emanote/static_gen/Coding/Haskell/Webapp-Example.html

2435 lines
83 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8' />
<meta name='viewport' content='width=device-width, initial-scale=1' />
<title>
Webapp-Development in Haskell Home
</title>
<meta property='og:description' content='Step-by-Step-Anleitung, wie man ein neues Projekt mit einer bereits erprobten Pipeline erstellt.' />
<meta property='og:site_name' content='Home' />
<meta property='og:image' content />
<meta property='og:type' content='website' />
<meta property='og:title' content='Webapp-Development in Haskell' />
<base href='/' />
<link href='favicon.svg' rel='icon' />
<script>
window.MathJax = {
startup: {
ready: () => {
MathJax.startup.defaultReady();
}
}
};
</script>
<script async id='MathJax-script' src='https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js'></script>
<!-- mermaid.js --><script src='https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.min.js'></script>
<script>
mermaid.initialize({startOnLoad:false});
mermaid.init(undefined,document.querySelectorAll(".mermaid"));
</script>
<!-- highlight.js -->
<link rel='stylesheet' href='https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.6.0/styles/hybrid.min.css' />
<script src='https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.6.0/highlight.min.js'></script>
<!-- Include languages that Emanote itself uses -->
<script src='https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.6.0/languages/haskell.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.6.0/languages/nix.min.js'></script>
<script>hljs.highlightAll();</script>
<link href='tailwind.css?instanceId=582ab847-21b9-4a5c-8fed-5c509514ffc2' rel='stylesheet' type='text/css' />
<style>
/* Heist error element */
strong.error {
color: lightcoral;
font-size: 90%;
font-family: monospace;
}
/* External link icon */
a[data-linkicon=""]::after {
content: ""
}
a[data-linkicon=none]::after {
content: ""
}
a[data-linkicon="external"]::after {
content: url('data:image/svg+xml,\
<svg xmlns="http://www.w3.org/2000/svg" height="0.7em" viewBox="0 0 20 20"> \
<g style="stroke:gray;stroke-width:1"> \
<line x1="5" y1="5" x2="5" y2="14" /> \
<line x1="14" y1="9" x2="14" y2="14" /> \
<line x1="5" y1="14" x2="14" y2="14" /> \
<line x1="5" y1="5" x2="9" y2="5" /> \
<line x1="10" y1="2" x2="17" y2="2" /> \
<line x1="17" y1="2" x2="17" y2="9" /> \
<line x1="10" y1="9" x2="17" y2="2" style="stroke-width:1.0" /> \
</g> \
</svg>');
}
a[data-linkicon="external"][href^="mailto:"]::after {
content: url('data:image/svg+xml,\
<svg \
xmlns="http://www.w3.org/2000/svg" \
height="0.7em" \
fill="none" \
viewBox="0 0 24 24" \
stroke="gray" \
stroke-width="2"> \
<path \
stroke-linecap="round" \
stroke-linejoin="round" \
d="M3 8l7.89 5.26a2 2 0 002.22 0L21 8M5 19h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z" /> \
</svg>');
}
</style>
<!-- What goes in this file will appear on near the end of <head>--><link rel='preload' href='_emanote-static/fonts/Work_Sans/WorkSans-VariableFont_wght.ttf' as='font' type='font/ttf' crossorigin />
<style>
@font-face {
font-family: 'WorkSans';
/* FIXME: This ought to be: ${ema:emanoteStaticLayerUrl}/fonts/Work_Sans/WorkSans-VariableFont_wght.ttf */
src: url(_emanote-static/fonts/Work_Sans/WorkSans-VariableFont_wght.ttf) format("truetype");
font-display: swap;
}
body {
font-family: 'WorkSans', sans-serif;
font-variation-settings: 'wght' 350;
}
a.mavenLinkBold {
font-variation-settings: 'wght' 400;
}
strong {
font-variation-settings: 'wght' 500;
}
h1,
h2,
h3,
h4,
h5,
h6,
header,
.header-font {
font-family: 'WorkSans', sans-serif;
}
h1 {
font-variation-settings: 'wght' 500;
}
h2 {
font-variation-settings: 'wght' 400;
}
h3 {
font-variation-settings: 'wght' 300;
}
</style>
<link rel='stylesheet' href='_emanote-static/inverted-tree.css' />
<link rel='stylesheet' href='_emanote-static/stork/flat.css' />
<!-- Custom Stork-search styling for Emanote -->
<style>
#stork-search-container {
z-index: 1000;
background-color: rgb(15 23 42/.8);
}
.stork-overflow-hidden-important {
overflow: hidden !important;
}
</style>
<script src='_emanote-static/stork/stork.js'></script>
<script id='emanote-stork' data-emanote-base-url='/'>
window.emanote = {};
window.emanote.stork = {
searchShown: false,
indexIsStale: false,
toggleSearch: function () {
window.emanote.stork.refreshIndex();
document.getElementById('stork-search-container').classList.toggle('hidden');
window.emanote.stork.searchShown = document.body.classList.toggle('stork-overflow-hidden-important');
if (window.emanote.stork.searchShown) {
document.getElementById('stork-search-input').focus();
}
},
clearSearch: function () {
document.getElementById('stork-search-container').classList.add('hidden');
document.body.classList.remove('stork-overflow-hidden-important');
window.emanote.stork.searchShown = false;
},
getBaseUrl: function () {
const baseUrl = document.getElementById("emanote-stork").getAttribute('data-emanote-base-url') || '/';
return baseUrl;
},
registerIndex: function (options) {
const indexName = 'emanote-search'; // used to match input[data-stork] attribute value
const indexUrl = window.emanote.stork.getBaseUrl() + '-/stork.st';
stork.register(
indexName,
indexUrl,
options);
},
init: function () {
if (document.readyState !== 'complete') {
window.addEventListener('load', function () {
stork.initialize(window.emanote.stork.getBaseUrl() + '_emanote-static/stork/stork.wasm');
window.emanote.stork.registerIndex();
});
document.addEventListener('keydown', event => {
if (window.emanote.stork.searchShown && event.key === 'Escape') {
window.emanote.stork.clearSearch();
event.preventDefault();
} else if ((event.key == 'k' || event.key == 'K') && (event.ctrlKey || event.metaKey)) {
window.emanote.stork.toggleSearch();
event.preventDefault();
}
});
} else {
// This section is called during Ema's hot reload.
//
// Mark the current index as stale, and refresh it *only when* the
// user actually invokes search.
//
// We do not refresh the index *right away*, as that will cause
// memory leaks in the browser. See
// https://github.com/srid/emanote/issues/411#issuecomment-1402056235
console.log("stork: Marking index as stale");
window.emanote.stork.markIndexAsStale();
}
},
markIndexAsStale: function () {
window.emanote.stork.indexIsStale = true;
},
refreshIndex: function () {
if (window.emanote.stork.indexIsStale) {
console.log("stork: Reloading index");
window.emanote.stork.indexIsStale = false;
// NOTE: This will leak memory. See the comment above.
window.emanote.stork.registerIndex({ forceOverwrite: true });
}
}
};
window.emanote.stork.init();
</script>
</head>
<!-- DoNotFormat -->
<!-- DoNotFormat -->
<body class='bg-gray-400 overflow-y-scroll'>
<div class='container mx-auto'>
<nav id='breadcrumbs' class='w-full text-gray-700 md:hidden'>
<div class='flex justify-left'>
<div class='w-full px-2 py-2 bg-gray-50'>
<ul class='flex flex-wrap text-lg'>
<li class='inline-flex items-center'>
<img style='width: 1rem;' src='favicon.svg' />
</li>
<li class='inline-flex items-center'>
<a class='px-1 font-bold' href=''>
Home
</a>
<svg fill='currentColor' viewBox='0 0 20 20' class='w-auto h-5 text-gray-400'>
<path fill-rule='evenodd' d='M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z' clip-rule='evenodd'></path>
</svg>
</li>
<li class='inline-flex items-center'>
<a class='px-1 font-bold' href='Coding'>
Coding
</a>
<svg fill='currentColor' viewBox='0 0 20 20' class='w-auto h-5 text-gray-400'>
<path fill-rule='evenodd' d='M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z' clip-rule='evenodd'></path>
</svg>
</li>
<li class='inline-flex items-center'>
<a class='px-1 font-bold' href='Coding/Haskell'>
Haskell
</a>
<svg fill='currentColor' viewBox='0 0 20 20' class='w-auto h-5 text-gray-400'>
<path fill-rule='evenodd' d='M7.293 14.707a1 1 0 010-1.414L10.586 10 7.293 6.707a1 1 0 011.414-1.414l4 4a1 1 0 010 1.414l-4 4a1 1 0 01-1.414 0z' clip-rule='evenodd'></path>
</svg>
</li>
</ul>
</div>
<button class='inline px-2 py-1 bg-gray-50 outline-none cursor-pointer focus:outline-none' title='Search (Ctrl+K)' type='button' onclick='window.emanote.stork.toggleSearch()'>
<svg xmlns='http://www.w3.org/2000/svg' style='width: 1rem;' class='hover:text-purple-700' f
fill='none' viewBox='0 0 24 24' stroke='currentColor' stroke-width='2'>
<path stroke-linecap='round' stroke-linejoin='round' d='M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z'></path>
</svg>
</button>
<button class='inline px-2 py-1 text-white bg-purple-600 outline-none cursor-pointer focus:outline-none' title='Toggle sidebar' type='button' onclick="toggleHidden('sidebar')">
<svg xmlns='http://www.w3.org/2000/svg' class='w-4' fill='none' viewBox='0 0 24 24' stroke='currentColor'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 6h16M4 12h16M4 18h16'></path>
</svg>
</button>
<script>
function toggleHidden(elemId) {
document.getElementById(elemId).classList.toggle("hidden");
}
</script>
</div>
</nav>
<div id='container' class='flex flex-nowrap flex-col md:flex-row bg-gray-50 md:mt-8 md:shadow-2xl md:mb-8'>
<!-- Sidebar column -->
<nav id='sidebar' class='flex-shrink hidden leading-relaxed md:block md:sticky md:top-0 md:h-full md:w-48 xl:w-64'>
<div class='px-2 py-2 text-gray-800'>
<div id='indexing-links' class='flex flex-row float-right p-2 space-x-2 text-gray-500'>
<a href='-/tags' title='View tags'>
<svg style='width: 1rem;' class='hover:text-purple-700' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 7h.01M7 3h5c.512 0 1.024.195 1.414.586l7 7a2 2 0 010 2.828l-7 7a2 2 0 01-2.828 0l-7-7A1.994 1.994 0 013 12V7a4 4 0 014-4z'>
</path>
</svg>
</a>
<a href='-/all' title='Expand full tree'>
<svg style='width: 1rem;' class='hover:text-purple-700' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 8V4m0 0h4M4 4l5 5m11-1V4m0 0h-4m4 0l-5 5M4 16v4m0 0h4m-4 0l5-5m11 5l-5-5m5 5v-4m0 4h-4'>
</path>
</svg>
</a>
<a title='Search (Ctrl+K)' class='cursor-pointer' onclick='window.emanote.stork.toggleSearch()'>
<svg xmlns='http://www.w3.org/2000/svg' style='width: 1rem;' class='hover:text-purple-700' f
fill='none' viewBox='0 0 24 24' stroke='currentColor' stroke-width='2'>
<path stroke-linecap='round' stroke-linejoin='round' d='M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z'></path>
</svg>
</a>
</div>
<div id='site-logo' class='pl-2'>
<div class='flex items-center my-2 space-x-2 justify-left'>
<a href='' title='Go to Home'>
<!-- The style width attribute here is to prevent huge
icon from displaying at those rare occasions when Tailwind
hasn't kicked in immediately on page load
-->
<img style='width: 1rem;' class='transition transform hover:scale-110 hover:opacity-80' src='favicon.svg' />
</a>
<a class='font-bold truncate' title='Go to Home' href=''>
Home
</a>
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='About me - Drezil' href='About'>
About me - Drezil
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Curriculum Vitae' href='About/CV'>
Curriculum Vitae
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Highlights of my experiences in the programming world' href='About/Experience'>
Highlights of my experiences in the programming world
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Work-Experience' href='About/Work'>
Work-Experience
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Android' href='Android'>
Android
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Einrichtung Android-Smartphones' href='Android/Einrichtung'>
Einrichtung Android-Smartphones
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Coding' href='Coding'>
Coding
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Haskell' href='Coding/Haskell'>
Haskell
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Talks und Posts zu Haskell' href='Coding/Haskell/Advantages'>
Talks und Posts zu Haskell
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-500' viewBox='0 0 20 20' fill='currentColor'>
<path d='M2 6a2 2 0 012-2h5l2 2h5a2 2 0 012 2v6a2 2 0 01-2 2H4a2 2 0 01-2-2V6z'></path>
</svg>
<a class='hover:underline truncate' title='Code-Snippets' href='Coding/Haskell/Code%20Snippets'>
Code-Snippets
</a>
<span class='text-gray-300' title='2 children inside'>
2
</span>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Fortgeschrittene funktionale Programmierung in Haskell' href='Coding/Haskell/FFPiH'>
Fortgeschrittene funktionale Programmierung in Haskell
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Lenses' href='Coding/Haskell/Lenses'>
Lenses
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold text-purple-600 hover:underline truncate' title='Webapp-Development in Haskell' href='Coding/Haskell/Webapp-Example'>
Webapp-Development in Haskell
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Webapp-Example: Main.hs' href='Coding/Haskell/Webapp-Example/Main.hs'>
Webapp-Example: Main.hs
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Webapp-Example: MyService/Types.hs' href='Coding/Haskell/Webapp-Example/MyService_Types.hs'>
Webapp-Example: MyService/Types.hs
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Openapi-generator' href='Coding/OpenAPI'>
Openapi-generator
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Health' href='Health'>
Health
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Mental Health' href='Health/Issues'>
Mental Health
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Logik für Dummies' href='Logik'>
Logik für Dummies
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Opinions' href='Opinions'>
Opinions
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Editors' href='Opinions/Editors'>
Editors
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Keyboard-Layouts' href='Opinions/Layout'>
Keyboard-Layouts
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Stuff' href='Stuff'>
Stuff
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Die Bielefeld-Verschwörung' href='Stuff/Bielefeldverschwoerung'>
Die Bielefeld-Verschwörung
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Todo' href='TODO'>
Todo
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Uni' href='Uni'>
Uni
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Studium generale / University-Life' href='Uni/Extracurricular'>
Studium generale / University-Life
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='Wie lerne ich richtig an der Uni?' href='Uni/Lernerfolg_an_der_Uni'>
Wie lerne ich richtig an der Uni?
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-4 h-4 flex-shrink-0 inline text-gray-700' viewBox='0 0 20 20' fill='currentColor'>
<path fill-rule='evenodd' d='M2 6a2 2 0 012-2h4l2 2h4a2 2 0 012 2v1H8a3 3 0 00-3 3v1.5a1.5 1.5 0 01-3 0V6z' clip-rule='evenodd'></path>
<path d='M6 12a2 2 0 012-2h8a2 2 0 012 2v2a2 2 0 01-2 2H2h2a2 2 0 002-2v-2z'></path>
</svg>
<a class='font-bold hover:underline truncate' title='Unix' href='Unix'>
Unix
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
<!-- Variable bindings for this tree-->
<!-- Rendering of this tree -->
<div class='pl-2'>
<!-- Node's rootLabel-->
<div class='flex items-center my-2 space-x-2 justify-left'>
<svg class='w-4 h-4 flex-shrink-0 inline' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z'>
</path>
</svg>
<a class='hover:underline truncate' title='SSH-Filter' href='Unix/SSH-Filter'>
SSH-Filter
</a>
</div>
<!-- Node's children forest, displayed only on active trees
TODO: Use <details> to toggle visibility?
-->
</div>
</div>
</div>
</nav>
<!-- Main body column -->
<div class='flex-1 w-full overflow-x-auto bg-white'>
<main class='px-4 py-4'>
<!-- DoNotFormat -->
<!-- DoNotFormat -->
<nav id='uptree' class='flipped tree' style='transform-origin: 50%;'>
<ul class='root'>
<li>
<ul>
<li>
<div class='text-gray-900 forest-link'>
<a href='Coding/OpenAPI'>
Openapi-generator
</a>
</div>
<ul>
<li>
<div class='text-gray-900 forest-link'>
<a href='Coding'>
Coding
</a>
</div>
<ul>
<li>
<div class='text-gray-900 forest-link'>
<a href=''>
Home
</a>
</div>
</li>
</ul>
</li>
</ul>
</li>
<li>
<div class='text-gray-900 forest-link'>
<a href='Coding/Haskell'>
Haskell
</a>
</div>
</li>
</ul>
</li>
</ul>
</nav>
<h1 class='flex items-end justify-center mb-4 p-3 bg-purple-100 text-5xl font-extrabold text-black rounded'>
<a class='z-40 tracking-tighter '>
Webapp-Development in Haskell
</a>
</h1>
<article class='overflow-auto'>
<!-- What goes in this file will appear on top of note body-->
<p class='mb-3'>
Step-by-Step-Anleitung, wie man ein neues Projekt mit einer bereits erprobten Pipeline erstellt.
</p>
<h2 id='definition-der-api' class='mt-6 mb-4 text-4xl font-bold text-gray-700 border-b-2'>Definition der API</h2>
<p class='mb-3'>
Erster Schritt ist immer ein wünsch-dir-was bei der Api-Defenition.
</p>
<p class='mb-3'>
Die meisten Services haben offensichtliche Anforderungen (Schnittstellen nach draußen, Schnittstellen intern, …). Diese kann man immer sehr gut in einem <code class='py-0.5 px-0.5 bg-gray-100'>Request -&gt; Response</code>-Model erfassen.
</p>
<p class='mb-3'>
Um die Anforderungen und Möglichkeiten des jeweiligen Services sauber zu erfassen und automatisiert zu prüfen, dummy-implementationen zu bekommen und vieles andere mehr, empfiehlt es sich den <a href='Coding/OpenAPI' class='text-purple-600 mavenLinkBold hover:underline' data-wikilink-type='WikiLinkTag'>openapi-generator</a> zu nutzen.
</p>
<p class='mb-3'>
Diese Definition läuft über openapi-v3 und kann z.b. mit Echtzeit-Vorschau im <a href='http://editor.swagger.io/' class='text-purple-600 hover:underline' data-linkicon='external' target='_blank' rel='noopener'>http://editor.swagger.io/</a> erspielen. Per Default ist der noch auf openapi-v2 (aka swagger), kann aber auch v3.
</p>
<p class='mb-3'>
Nach der Definition, was man am Ende haben möchte, muss man sich entscheiden, in welcher Sprache man weiter entwickelt. Ich empfehle aus verschiedenen Gründen primär 2 Sprachen: Python-Microservices (weil die ML-Libraries sehr gut sind, allerdings Änderungen meist schwer sind und der Code wenig robust - meist nur 1 API-Endpunkt pro service) und Haskell (Stabilität, Performace, leicht zu ändern, gut anzupassen).
</p>
<p class='mb-3'>
Im folgenden wird (aus offensichtlichen Gründen) nur auf das Haskell-Projekt eingegangen.
</p>
<h2 id='startprojekt-in-haskell' class='mt-6 mb-4 text-4xl font-bold text-gray-700 border-b-2'>Startprojekt in Haskell</h2><h3 id='erstellen-eines-neuen-projektes' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Erstellen eines neuen Projektes</h3>
<p class='mb-3'>
Zunächst erstellen wir in normales Haskell-Projekt ohne Funktionalität & Firlefanz:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='bash language-bash'>stack new myservice</code></pre></div>
<p class='mb-3'>
Dies erstellt ein neues Verzeichnis und das generelle scaffolding. Nach einer kurzen Anpassung der <code class='py-0.5 px-0.5 bg-gray-100'>stack.yaml</code> (resolver auf unserer setzen; aktuell: <code class='py-0.5 px-0.5 bg-gray-100'>lts-17.4</code>) fügen wir am Ende der Datei
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='yaml language-yaml'>allow-newer: true
ghc-options:
"$locals": -fwrite-ide-info</code></pre></div>
<p class='mb-3'>
ein. Anschließend organisieren™ wir uns noch eine gute <code class='py-0.5 px-0.5 bg-gray-100'>.gitignore</code> und initialisieren das git mittels <code class='py-0.5 px-0.5 bg-gray-100'>git init; git add .; git commit -m "initial scaffold"</code>
</p>
<h3 id='generierung-der-api' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Generierung der API</h3>
<p class='mb-3'>
Da die API immer wieder neu generiert werden kann (und sollte!) liegt sich in einem unterverzeichnis des Hauptprojektes.
</p>
<p class='mb-3'>
Initial ist es das einfachste ein leeres temporäres Verzeichnis woanders zu erstellen, die <code class='py-0.5 px-0.5 bg-gray-100'>api-doc.yml</code> hinein kopieren und folgendes ausführen:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='bash language-bash'>openapi-generator generate -g haskell -o . -i api-doc.yml</code></pre></div>
<p class='mb-3'>
Dieses erstellt einem dann eine komplette library inkl. Datentypen. Wichtig: Der Name in der <code class='py-0.5 px-0.5 bg-gray-100'>api-doc</code> sollte vom Namen des Services (oben <code class='py-0.5 px-0.5 bg-gray-100'>myservice</code>) abweichen - entweder in Casing oder im Namen direkt. Suffixe wie API schneidet der Generator hier leider ab. (Wieso das ganze? Es entstehen nachher 2 libraries, <code class='py-0.5 px-0.5 bg-gray-100'>foo</code> & <code class='py-0.5 px-0.5 bg-gray-100'>fooAPI</code>. Da der generator das API abschneidet endet man mit foo & foo und der compiler meckert, dass er nicht weiß, welche lib gemeint ist).
</p>
<p class='mb-3'>
danach: wie gewohnt <code class='py-0.5 px-0.5 bg-gray-100'>git init; git add .; git commit -m "initial"</code>. Auf dem Server der Wahl (github, gitea, gitlab, …) nun ein Repository erstellen (am Besten: <code class='py-0.5 px-0.5 bg-gray-100'>myserviceAPI</code> - nach Konvention ist alles auf API endend autogeneriert!) und den Anweisungen nach ein remote hinzufügen & pushen.
</p>
<h4 id='wieder-zurück-im-haskell-service' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Wieder zurück im Haskell-Service</h4>
<p class='mb-3'>
In unserem eigentlichen Service müssen wir nun die API einbinden. Dazu erstellen wir ein Verzeichnis <code class='py-0.5 px-0.5 bg-gray-100'>libs</code> (Konvention) und machen ein <code class='py-0.5 px-0.5 bg-gray-100'>git submodule add &lt;repository-url&gt; libs/myserviceAPI</code>
</p>
<p class='mb-3'>
Git hat nun die API in das submodul gepackt und wir können das oben erstellte temporäre Verzeichnis wieder löschen.
</p>
<p class='mb-3'>
Anschließend müssen wir stack noch erklären, dass wir die API da nun liegen haben und passen wieder die <code class='py-0.5 px-0.5 bg-gray-100'>stack.yaml</code> an, indem wir das Verzeichnis unter packages hinzufügen.
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='yaml language-yaml'>packages:
- .
- libs/myserviceAPI # &lt;&lt;</code></pre></div>
<p class='mb-3'>
Nun können wir in der <code class='py-0.5 px-0.5 bg-gray-100'>package.yaml</code> (oder <code class='py-0.5 px-0.5 bg-gray-100'>myservice.cabal</code>, falls kein <code class='py-0.5 px-0.5 bg-gray-100'>hpack</code> verwendet wird) unter den dependencies unsere API hinzufügen (name wie die cabal-Datei in <code class='py-0.5 px-0.5 bg-gray-100'>libs/myserviceAPI</code>).
</p>
<h3 id='einbinden-anderer-microservices' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Einbinden anderer Microservices</h3>
<p class='mb-3'>
Funktioniert komplett analog zu dem vorgehen oben (ohne das generieren natürlich <span class='emoji' data-emoji='grin' style='font-family: emoji'>😁</span>). <code class='py-0.5 px-0.5 bg-gray-100'>stack.yaml</code> editieren und zu den packages hinzufügen:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='yaml language-yaml'>packages:
- .
- libs/myserviceAPI
- libs/myCoolMLServiceAPI</code></pre></div>
<p class='mb-3'>
in der <code class='py-0.5 px-0.5 bg-gray-100'>package.yaml</code> (oder der cabal) die dependencies hinzufügen und schon haben wir die Features zur Verfügung und können gegen diese Services reden.
</p>
<h3 id='entfernen-von-anderen-technologienmicroservices' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Entfernen von anderen Technologien/Microservices</h3>
<p class='mb-3'>
In git ist das entfernen von Submodules etwas frickelig, daher hier ein copy&amp;paste der <a href='https://gist.github.com/myusuf3/7f645819ded92bda6677' class='text-purple-600 hover:underline' data-linkicon='external' target='_blank' rel='noopener'>GitHub-Antwort</a>:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='bash language-bash'>## Remove the submodule entry from .git/config
git submodule deinit -f path/to/submodule
## Remove the submodule directory from the superproject's .git/modules directory
rm-rf .git/modules/path/to/submodule
## Remove the entry in .gitmodules and remove the submodule directory located at path/to/submodule
git rm-f path/to/submodule</code></pre></div>
<p class='mb-3'>
Falls das nicht klappt, gibt es alternative Vorschläge unter dem Link oben.
</p>
<h3 id='woher-weiss-ich-was-wo-liegt-dokumentation-halloo' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Woher weiss ich, was wo liegt? Dokumentation? Halloo??</h3>
<p class='mb-3'>
Keine Panik. Ein <code class='py-0.5 px-0.5 bg-gray-100'>stack haddock --open</code> hilft da. Das generiert die Dokumentation für alle in der <code class='py-0.5 px-0.5 bg-gray-100'>package.yaml</code> (oder cabal-file) eingetragenen dependencies inkl. aller upstream-dependencies. Man bekommt also eine komplette lokale Dokumentation von allem. Geöffnet wird dann die Paket-Startseite inkl. der direkten dependencies:
</p>
<p class='mb-3'>
Es gibt 2 wichtige Pfade im Browser:
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
…../all/index.html - hier sind alle Pakete aufgeführt
</li>
<li>
…../index.html - hier sind nur die direkten dependencies aufgeführt.
</li>
</ul>
<p class='mb-3'>
Wenn man einen lokalen Webserver startet kann man mittels “s” auch die interaktive Suche öffnen (Suche nach Typen, Funktionen, Signaturen, etc.). In Bash mit <code class='py-0.5 px-0.5 bg-gray-100'>python3</code> geht das z.b. einfach über:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='bash language-bash'>cd $(stack path --local-doc-root)
python3 -m SimpleHTTPServer 8000
firefox "http://localhost:8000"</code></pre></div><h3 id='implementation-des-services-und-start' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Implementation des Services und Start</h3><h4 id='loaderbootstrapper' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Loader/Bootstrapper</h4>
<p class='mb-3'>
Generelles Vorgehen:
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
<p class='mb-3'>
in <code class='py-0.5 px-0.5 bg-gray-100'>app/Main.hs</code>: Hier ist quasi immer nur eine Zeile drin: <code class='py-0.5 px-0.5 bg-gray-100'>main = myServiceMain</code>
</p>
<p class='mb-3'>
Grund: Applications tauchen nicht im Haddock auf. Also haben wir ein “src”-Modul, welches hier nur geladen & ausgeführt wird.
</p>
</li>
<li>
<p class='mb-3'>
in <code class='py-0.5 px-0.5 bg-gray-100'>src/MyService.hs</code>: <code class='py-0.5 px-0.5 bg-gray-100'>myServiceMain :: IO ()</code> definieren
</p>
</li>
</ul>
<p class='mb-3'>
Für die Main kann man prinzipiell eine Main andere Services copy/pasten. Im folgenden eine Annotierte main-Funktion - zu den einzelnen Voraussetzungen kommen wir im Anschluss.
</p>
<section title='Embedded note' class='p-4 mx-2 mb-2 bg-white border-2 rounded-lg shadow-inner'>
<details>
<summary class='flex items-center justify-center text-2xl italic bg-purple-50 rounded py-1 px-2 mb-3'>
<header style='display:list-item'>
<a href='Coding/Haskell/Webapp-Example/Main.hs'>
Webapp-Example: Main.hs
</a>
</header>
</summary>
<div>
<p class='mb-3'>
Wie man das verwendet, siehe <a href='Coding/Haskell/Webapp-Example' class='text-purple-600 mavenLinkBold hover:underline' data-wikilink-type='WikiLinkTag'>Webapp-Development in Haskell</a>.
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='haskell language-haskell'>{-# OPTIONS_GHC -Wno-name-shadowing #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
module MyService where
-- generische imports aus den dependencies/base, nicht in der prelude
import Codec.MIME.Type
import Configuration.Dotenv as Dotenv
import Control.Concurrent (forkIO, threadDelay)
import Control.Concurrent.Async
import Control.Concurrent.STM
import Control.Monad
import Control.Monad.Catch
import Control.Monad.Except
import Conversion
import Conversion.Text ()
import Data.Binary.Builder
import Data.String (IsString (..))
import Data.Time
import Data.Time.Clock
import Data.Time.Format
import Data.Default
import Network.HostName
import Network.HTTP.Client as HTTP hiding
(withConnection)
import Network.HTTP.Types (Status, statusCode)
import Network.Mom.Stompl.Client.Queue
import Network.Wai (Middleware)
import Network.Wai.Logger
import Network.Wai.Middleware.Cors
import Network.Wai.Middleware.RequestLogger (OutputFormat (..),
logStdout,
mkRequestLogger,
outputFormat)
import Servant.Client (mkClientEnv,
parseBaseUrl)
import System.Directory
import System.Envy
import System.IO
import System.Log.FastLogger
import Text.PrettyPrint.GenericPretty
-- generische imports, aber qualified, weil es sonst zu name-clashes kommt
import qualified Data.ByteString as BS
-- import qualified Data.ByteString.Char8 as BS8
import qualified Data.ByteString.Lazy as LBS
import qualified Network.HTTP.Client.TLS as UseDefaultHTTPSSettings (tlsManagerSettings)
import qualified Network.Mom.Stompl.Client.Queue as AMQ
import qualified Network.Wai as WAI
-- Handler für den MyServiceBackend-Typen und Imports aus den Libraries
import MyService.Handler as H -- handler der H.myApiEndpointV1Post implementiert
import MyService.Types -- weitere Type (s. nächste box)
import MyServiceGen.API as MS -- aus der generierten library
myServicemain :: IO ()
myServicemain = do
-- .env-Datei ins Prozess-Environment laden, falls noch nicht von außen gesetzt
void $ loadFile $ Dotenv.Config [".env"] [] False
-- Config holen (defaults + overrides aus dem Environment)
sc@ServerConfig{..} &lt;- decodeWithDefaults defConfig
-- Backend-Setup
-- legt sowas wie Proxy-Server fest und wo man wie dran kommt. Benötigt für das Sprechen mit anderen Microservices
let defaultHTTPSSettings = UseDefaultHTTPSSettings.tlsManagerSettings { managerResponseTimeout = responseTimeoutMicro $ 1000 * 1000 * myserviceMaxTimeout }
createBackend url proxy = do
manager &lt;- newManager . managerSetProxy proxy
$ defaultHTTPSSettings
url' &lt;- parseBaseUrl url
return (mkClientEnv manager url')
internalProxy = case myserviceInternalProxyUrl of
"" -&gt; noProxy
url -&gt; useProxy $ HTTP.Proxy (fromString url) myserviceInternalProxyPort
-- externalProxy = case myserviceExternalProxyUrl of
-- "" -&gt; noProxy
-- url -&gt; useProxy $ HTTP.Proxy (fromString url) myserviceExternalProxyPort
-- Definieren & Erzeugen der Funktionen um die anderen Services anzusprechen.
calls &lt;- (,)
&lt;$&gt; createBackend myserviceAUri internalProxy
&lt;*&gt; createBackend myserviceBUri internalProxy
-- Logging-Setup
hSetBuffering stdout LineBuffering
hSetBuffering stderr LineBuffering
-- Infos holen, brauchen wir später
myName &lt;- getHostName
today &lt;- formatTime defaultTimeLocale "%F" . utctDay &lt;$&gt; getCurrentTime
-- activeMQ-Transaktional-Queue zum schreiben nachher vorbereiten
amqPost &lt;- newTQueueIO
-- bracket a b c == erst a machen, ergebnis an c als variablen übergeben. Schmeisst c ne exception/wird gekillt/..., werden die variablen an b übergeben.
bracket
-- logfiles öffnen
(LogFiles &lt;$&gt; openFile ("/logs/myservice-"&lt;&gt;myName&lt;&gt;"-"&lt;&gt;today&lt;&gt;".info") AppendMode
&lt;*&gt; openFile (if myserviceDebug then "/logs/myservice-"&lt;&gt;myName&lt;&gt;"-"&lt;&gt;today&lt;&gt;".debug" else "/dev/null") AppendMode
&lt;*&gt; openFile ("/logs/myservice-"&lt;&gt;myName&lt;&gt;"-"&lt;&gt;today&lt;&gt;".error") AppendMode
&lt;*&gt; openFile ("/logs/myservice-"&lt;&gt;myName&lt;&gt;"-"&lt;&gt;today&lt;&gt;".timings") AppendMode
)
-- und bei exception/beendigung schlißen.h
(\(LogFiles a b c d) -&gt; mapM_ hClose [a,b,c,d])
$ \logfiles -&gt; do
-- logschreibe-funktionen aliasen; log ist hier abstrakt, iolog spezialisiert auf io.
let log = printLogFiles logfiles :: MonadIO m =&gt; [LogItem] -&gt; m ()
iolog = printLogFilesIO logfiles :: [LogItem] -&gt; IO ()
-- H.myApiEndpointV1Post ist ein Handler (alle Handler werden mit alias H importiert) und in einer eigenen Datei
-- Per Default bekommen Handler sowas wie die server-config, die Funktionen um mit anderen Services zu reden, die AMQ-Queue um ins Kibana zu loggen und eine Datei-Logging-Funktion
-- Man kann aber noch viel mehr machen - z.b. gecachte Daten übergeben, eine Talk-Instanz, etc. pp.
server = MyServiceBackend{ myApiEndpointV1Post = H.myApiEndpointV1Post sc calls amqPost log
}
config = MS.Config $ "http://" ++ myserviceHost ++ ":" ++ show myservicePort ++ "/"
iolog . pure . Info $ "Using Server configuration:"
iolog . pure . Info $ pretty sc { myserviceActivemqPassword = "******" -- Do NOT log the password ;)
, myserviceMongoPassword = "******"
}
-- alle Services starten (Hintergrund-Aktionen wie z.b. einen MongoDB-Dumper, einen Talk-Server oder wie hier die ActiveMQ
void $ forkIO $ keepActiveMQConnected sc iolog amqPost
-- logging-Framework erzeugen
loggingMW &lt;- loggingMiddleware
-- server starten
if myserviceDebug
then runMyServiceMiddlewareServer config (cors (\_ -&gt; Just (simpleCorsResourcePolicy {corsRequestHeaders = ["Content-Type"]})) . loggingMW . logStdout) server
else runMyServiceMiddlewareServer config (cors (\_ -&gt; Just (simpleCorsResourcePolicy {corsRequestHeaders = ["Content-Type"]}))) server
-- Sollte bald in die Library hs-stomp ausgelagert werden
-- ist ein Beispiel für einen ActiveMQ-Dumper
keepActiveMQConnected :: ServerConfig -&gt; ([LogItem] -&gt; IO ()) -&gt; TQueue BS.ByteString -&gt; IO ()
keepActiveMQConnected sc@ServerConfig{..} printLog var = do
res &lt;- handle (\(e :: SomeException) -&gt; do
printLog . pure . Error $ "Exception in AMQ-Thread: "&lt;&gt;show e
return $ Right ()
) $ AMQ.try $ do -- catches all AMQ-Exception that we can handle. All others bubble up.
printLog . pure . Info $ "AMQ: connecting..."
withConnection myserviceActivemqHost myserviceActivemqPort [ OAuth myserviceActivemqUsername myserviceActivemqPassword
, OTmo (30*1000) {- 30 sec timeout -}
]
[] $ \c -&gt; do
let oconv = return
printLog . pure . Info $ "AMQ: connected"
withWriter c "Chaos-Logger for Kibana" "chaos.logs" [] [] oconv $ \writer -&gt; do
printLog . pure . Info $ "AMQ: queue created"
let postfun = writeQ writer (Type (Application "json") []) []
void $ race
(forever $ atomically (readTQueue var) &gt;&gt;= postfun)
(threadDelay (600*1000*1000)) -- wait 10 Minutes
-- close writer
-- close connection
-- get outside of all try/handle/...-constructions befor recursing.
case res of
Left ex -&gt; do
printLog . pure . Error $ "AMQ: "&lt;&gt;show ex
keepActiveMQConnected sc printLog var
Right _ -&gt; keepActiveMQConnected sc printLog var
-- Beispiel für eine Custom-Logging-Middleware.
-- Hier werden z.B. alle 4xx-Status-Codes inkl. Payload ins stdout-Log geschrieben.
-- Nützlich, wenn die Kollegen ihre Requests nicht ordentlich schreiben können und der Server das Format zurecht mit einem BadRequest ablehnt ;)
loggingMiddleware :: IO Middleware
loggingMiddleware = liftIO $ mkRequestLogger $ def { outputFormat = CustomOutputFormatWithDetails out }
where
out :: ZonedDate -&gt; WAI.Request -&gt; Status -&gt; Maybe Integer -&gt; NominalDiffTime -&gt; [BS.ByteString] -&gt; Builder -&gt; LogStr
out _ r status _ _ payload _
| statusCode status &lt; 300 = ""
| statusCode status &gt; 399 && statusCode status &lt; 500 = "Error code "&lt;&gt;toLogStr (statusCode status) &lt;&gt;" sent. Request-Payload was: "&lt;&gt; mconcat (toLogStr &lt;$&gt; payload) &lt;&gt; "\n"
| otherwise = toLogStr (show r) &lt;&gt; "\n"
</code></pre></div>
</div>
</details>
</section>
<h4 id='weitere-instanzen-und-definitionen-die-der-generator-noch-nicht-macht' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Weitere Instanzen und Definitionen, die der Generator (noch) nicht macht</h4>
<p class='mb-3'>
In der <code class='py-0.5 px-0.5 bg-gray-100'>Myservice.Types</code> werden ein paar hilfreiche Typen und Typ-Instanzen definiert. Im Folgenden geht es dabei um Dinge für:
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>Envy</code>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
Laden von <code class='py-0.5 px-0.5 bg-gray-100'>$ENV_VAR</code> in Datentypen
</li>
<li>
Definitionen für Default-Settings
</li>
</ul>
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>ServerConfig</code>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
Definition der Server-Konfiguration & Benennung der Environment-Variablen
</li>
</ul>
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>ExtraTypes</code>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
ggf. Paketweite extra-Typen, die der Generator nicht macht, weil sie nicht aus der API kommen (z.B. cache)
</li>
</ul>
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>Out</code>/<code class='py-0.5 px-0.5 bg-gray-100'>BSON</code>-Instanzen
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
Der API-Generator generiert nur wenige Instanzen automatisch (z.B. <code class='py-0.5 px-0.5 bg-gray-100'>aeson</code>), daher werden hier die fehlenden definiert.
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>BSON</code>: Kommunikation mit <code class='py-0.5 px-0.5 bg-gray-100'>MongoDB</code>
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>Out</code>: pretty-printing im Log
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
Nur nötig, wenn man pretty-printing via <code class='py-0.5 px-0.5 bg-gray-100'>Out</code> statt über Generics wie z.b. <code class='py-0.5 px-0.5 bg-gray-100'>pretty-generic</code> oder die automatische Show-Instanz via <code class='py-0.5 px-0.5 bg-gray-100'>prerryShow</code> macht.
</li>
</ul>
</li>
</ul>
</li>
</ul>
<section title='Embedded note' class='p-4 mx-2 mb-2 bg-white border-2 rounded-lg shadow-inner'>
<details>
<summary class='flex items-center justify-center text-2xl italic bg-purple-50 rounded py-1 px-2 mb-3'>
<header style='display:list-item'>
<a href='Coding/Haskell/Webapp-Example/MyService_Types.hs'>
Webapp-Example: MyService/Types.hs
</a>
</header>
</summary>
<div>
<p class='mb-3'>
Anleitung siehe <a href='Coding/Haskell/Webapp-Example' class='text-purple-600 mavenLinkBold hover:underline' data-wikilink-type='WikiLinkTag'>Webapp-Development in Haskell</a>.
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='haskell language-haskell'>{-# OPTIONS_GHC -Wno-orphans #-}
{-# OPTIONS_GHC -Wno-name-shadowing #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DerivingVia #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE RecordWildCards #-}
module MyService.Types where
import Data.Aeson (FromJSON, ToJSON)
import Data.Text
import Data.Time.Clock
import GHC.Generics
import System.Envy
import Text.PrettyPrint (text)
import Text.PrettyPrint.GenericPretty
-- Out hat hierfür keine Instanzen, daher kurz eine einfach Definition.
instance Out Text where
doc = text . unpack
docPrec i a = text $ showsPrec i a ""
instance Out UTCTime where
doc = text . show
docPrec i a = text $ showsPrec i a ""
-- Der ServerConfig-Typ. Wird mit den defaults unten initialisiert, dann mit den Variablen aus der .env-Datei überschrieben und zum Schluss können Serveradmins diese via $MYSERVICE_FOO nochmal überschreiben.
data ServerConfig = ServerConfig
{ myserviceHost :: String -- ^ Environment: $MYSERVICE_HOST
, myservicePort :: Int -- ^ Environment: $MYSERVICE_PORT
, myserviceMaxTimeout :: Int -- ^ Environment: $MYSERVICE_MAX_TIMEOUT
, myserviceInternalProxyUrl :: String -- ^ Environment: $MYSERVICE_INTERNAL_PROXY_URL
, myserviceInternalProxyPort :: Int -- ^ Environment: $MYSERVICE_INTERNAL_PROXY_PORT
, myserviceExternalProxyUrl :: String -- ^ Environment: $MYSERVICE_EXTERNAL_PROXY_URL
, myserviceExternalProxyPort :: Int -- ^ Environment: $MYSERVICE_EXTERNAL_PROXY_PORT
, myserviceActivemqHost :: String -- ^ Environment: $MYSERVICE_ACTIVEMQ_HOST
, myserviceActivemqPort :: Int -- ^ Environment: $MYSERVICE_ACTIVEMQ_PORT
, myserviceActivemqUsername :: String -- ^ Environment: $MYSERVICE_ACTIVEMQ_USERNAME
, myserviceActivemqPassword :: String -- ^ Environment: $MYSERVICE_ACTIVEMQ_PASSWORD
, myserviceMongoUsername :: String -- ^ Environment: $MYSERVICE_MONGO_USERNAME
, myserviceMongoPassword :: String -- ^ Environment: $MYSERVICE_MONGO_PASSWORD
, myserviceDebug :: Bool -- ^ Environment: $MYSERVICE_DEBUG
} deriving (Show, Eq, Generic)
-- Default-Konfigurations-Instanz für diesen Service.
instance DefConfig ServerConfig where
defConfig = ServerConfig "0.0.0.0" 8080 20
""
""
""
0
""
0
""
0
""
""
""
""
False
-- Kann auch aus dem ENV gefüllt werden
instance FromEnv ServerConfig
-- Und hübsch ausgegeben werden.
instance Out ServerConfig
instance Out Response
instance FromBSON Repsonse -- FromBSON-Instanz geht immer davon aus, dass alle keys da sind (ggf. mit null bei Nothing).</code></pre></div>
</div>
</details>
</section>
<h4 id='was-noch-zu-tun-ist' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Was noch zu tun ist</h4>
<p class='mb-3'>
Den Service implementieren. Einfach ein neues Modul aufmachen (z.B. <code class='py-0.5 px-0.5 bg-gray-100'>MyService.Handler</code> oder <code class='py-0.5 px-0.5 bg-gray-100'>MyService.DieserEndpunktbereich</code>/<code class='py-0.5 px-0.5 bg-gray-100'>MyService.JenerEndpunktbereich</code>) und dort die Funktion implementieren, die man in der <code class='py-0.5 px-0.5 bg-gray-100'>Main.hs</code> benutzt hat. In dem Handler habt ihr dann keinen Stress mehr mit Validierung, networking, logging, etc. pp. weil alles in der Main abgehandelt wurde und ihr nur noch den “Happy-Case” implementieren müsst. Beispiel für unseren Handler oben:
</p>
<div class='py-0.5 mb-3 text-sm'><pre><code class='haskell language-haskell'>myApiEndpointV1Post :: MonadIO m =&gt; ServerConfig -&gt; (ClientEnv,ClientEnv) -&gt; TQueue BS.ByteString -&gt; ([LogItem] -&gt; IO ()) -&gt; Request -&gt; m Response
myApiEndpointV1Post sc calls amqPost log req = do
liftIO . log $ [Info $ "recieved "&lt;&gt;pretty req] -- input-logging
liftIO . atomically . writeTQueue . LBS.toStrict $ "{\"hey Kibana, i recieved:\"" &lt;&gt; A.encode (pretty req) &lt;&gt; "}" -- log in activeMQ/Kibana
--- .... gaaaanz viel komplizierter code um die Response zu erhalten ;)
let ret = Response 1337 Nothing -- dummy-response ;)
-- gegeben wir haben eine gültige mongodb-pipe;
-- mehr logik will ich in die Beispiele nicht packen.
-- Man kann die z.b. als weiteren Wert in einer TMVar (damit man sie ändern & updaten kann) an die Funktion übergeben.
liftIO . access pipe master "DatabaseName" $ do
ifM (auth (myServiceMongoUsername sc) (myServiceMongoPassword sc)) (return ()) (liftIO . printLog . pure . Error $ "MongoDB: Login failed.")
save "DatabaseCollection" ["_id" =: 1337, "entry" =: ret] -- selbe id wie oben ;)
return ret</code></pre></div>
<p class='mb-3'>
Diese dummy-Antwort führt auf, wie gut man die ganzen Sachen mischen kann.
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
Logging in die Dateien/<code class='py-0.5 px-0.5 bg-gray-100'>stdout</code> - je nach Konfiguration
</li>
<li>
Logging von Statistiken in Kibana
</li>
<li>
Speichern der Antwort in der MongoDB
</li>
<li>
Generieren einer Serverantwort und ausliefern dieser über die Schnittstelle
</li>
</ul>
<h4 id='tipps--tricks' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Tipps & Tricks</h4><h5 id='dateien-die-statisch-ausgeliefert-werden-sollen' class='mt-6 mb-2 text-xl font-bold text-gray-700'>Dateien, die statisch ausgeliefert werden sollen</h5>
<p class='mb-3'>
Hierzu erstellt man ein Verzeichnis <code class='py-0.5 px-0.5 bg-gray-100'>static/</code> (Konvention; ist im generator so generiert, dass das ausgeliefert wird). Packt man hier z.b. eine <code class='py-0.5 px-0.5 bg-gray-100'>index.html</code> rein, erscheint die, wenn man den Service ansurft.
</p>
<h5 id='wie-bekomme-ich-diese-fancy-preview-hin' class='mt-6 mb-2 text-xl font-bold text-gray-700'>Wie bekomme ich diese fancy Preview hin?</h5>
<p class='mb-3'>
Der Editor, der ganz am Anfang zum Einsatz gekommen ist, braucht nur die <code class='py-0.5 px-0.5 bg-gray-100'>api-doc.yml</code> um diese Ansicht zu erzeugen. Daher empfiehlt sich hier ein angepasster Fork davon indem die Pfade in der index.html korrigiert sind. Am einfachsten (und von den meisten services so benutzt): In meiner Implementation liegt dann nach dem starten auf http://localhost:PORT/ui/ und kann direkt dort getestet werden.
</p>
<h5 id='wie-sorge-ich-für-bessere-warnungen-damit-der-compiler-meine-bugs-fängt' class='mt-6 mb-2 text-xl font-bold text-gray-700'>Wie sorge ich für bessere Warnungen, damit der Compiler meine Bugs fängt?</h5><div class='py-0.5 mb-3 text-sm'><pre><code class='bash language-bash'>stack build --file-watch --ghc-options '-freverse-errors -W -Wall -Wcompat' --interleaved-output</code></pre></div>
<p class='mb-3'>
Was tut das?
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>--file-watch</code>: automatisches (minimales) kompilieren bei dateiänderungen
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>--ghc-options</code>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>-freverse-errors</code>: Fehlermeldungen in umgekehrter Reihenfolge (Erster Fehler ganz unten; wenig scrollen )
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>-W</code>: Warnungen an
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>-Wall</code>: Alle sinnvollen Warnungen an (im gegensatz zu <code class='py-0.5 px-0.5 bg-gray-100'>-Weverything</code>, was WIRKLICH alles ist )
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>-Wcompat</code>: Warnungen für Sachen, die in der nächsten Compilerversion kaputt brechen werden & vermieden werden sollten
</li>
</ul>
</li>
<li>
<code class='py-0.5 px-0.5 bg-gray-100'>--interleaved-output</code>: stack-log direkt ausgeben & nicht in Dateien schreiben und die dann am ende zusammen cat'en.
</li>
</ul>
<p class='mb-3'>
Um pro Datei Warnungen auszuschalten (z.B. weil man ganz sicher weiss, was man tut -.-): <code class='py-0.5 px-0.5 bg-gray-100'>{-# OPTIONS_GHC -Wno-whatsoever #-}</code> als pragma in die Datei.
</p>
<p class='mb-3'>
<strong>Idealerweise sollte das Projekt keine Warnungen erzeugen.</strong>
</p>
<h3 id='deployment' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>Deployment</h3>
<p class='mb-3'>
Als Beispiel sei hier ein einfaches Docker-Build mit Jenkins-CI gezeigt, weil ich das aus Gründen rumliegen hatte. Kann man analog in fast alle anderen CI übersetzen.
</p>
<h4 id='docker' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Docker</h4>
<p class='mb-3'>
Die angehängten Scripte gehen von einer Standard-Einrichtung aus (statische Sachen in static, 2-3 händische Anpassungen auf das eigene Projekt nach auspacken). Nachher liegt dann auch unter static/version die gebaute Versionsnummer & kann abgerufen werden. In der <code class='py-0.5 px-0.5 bg-gray-100'>Dockerfile.release</code> und der <code class='py-0.5 px-0.5 bg-gray-100'>Jenkinsfile</code> müssen noch Anpassungen gemacht werden. Konkret:
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
in der <code class='py-0.5 px-0.5 bg-gray-100'>Dockerfile.release</code>: alle <code class='py-0.5 px-0.5 bg-gray-100'>&lt;&lt;&lt;HIER&gt;&gt;&gt;</code>-Stellen sinnvoll befüllen
</li>
<li>
in der <code class='py-0.5 px-0.5 bg-gray-100'>Jenkinsfile</code> die defs für “servicename” und “servicebinary” ausfüllen. Binary ist das, was bei stack exec aufgerufen wird; name ist der Image-Name für das docker-repository.
</li>
</ul>
<h4 id='jenkins' class='mt-6 mb-2 text-2xl font-bold text-gray-700'>Jenkins</h4>
<p class='mb-3'>
Änderungen die dann noch gemacht werden müssen:
</p>
<ul class='my-3 ml-6 space-y-1 list-disc'>
<li>
git-repository URL anpassen
</li>
<li>
Environment-Vars anpassen ($BRANCH = test & live haben keine zusatzdinger im docker-image-repository; ansonsten hat das image $BRANCH im Namen)
</li>
</ul>
<p class='mb-3'>
Wenn das fertig gebaut ist, liegt im test/live-repository ein docker-image namens <code class='py-0.5 px-0.5 bg-gray-100'>servicename:version</code>.
</p>
<h3 id='omg-ich-muss-meine-api-ändern-was-mache-ich-nun' class='mt-6 mb-2 text-3xl font-bold text-gray-700'>OMG! Ich muss meine API ändern. Was mache ich nun?</h3>
<ul class='my-3 ml-6 space-y-1 list-decimal list-inside'>
<li>
api-doc.yml bearbeiten, wie gewünscht
</li>
<li>
mittels generator die Api & submodule neu generieren
</li>
<li>
ggf. custom Änderungen übernehmen (:Gitdiffsplit hilft)
</li>
<li>
Alle Compilerfehler + Warnungen in der eigentlichen Applikation fixen
</li>
<li>
If it comipilez, ship it! (Besser nicht <span class='emoji' data-emoji='grin' style='font-family: emoji'>😁</span>)
</li>
</ul>
<!-- div class="flex items-center justify-center mt-2">
<ema:metadata>
<with var="template">
<a class="text-gray-300 hover:text-${theme}-600 text-sm" title="Edit this page on GitHub"
href="${value:editBaseUrl}/${ema:note:source-path}">
<svg xmlns="http://www.w3.org/2000/svg" class="h-6 w-6" fill="none" viewBox="0 0 24 24" stroke="currentColor">
<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2"
d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" />
</svg>
</a>
</with>
</ema:metadata>
</div -->
</article>
<div class='flex flex-col lg:flex-row lg:space-x-2'>
<div class='flex-1 p-4 mt-8 bg-gray-100 rounded'>
<header class='mb-2 text-xl font-semibold text-gray-500'>Links to this page</header>
<ul class='space-y-1'>
<li>
<a class='text-purple-600 mavenLinkBold hover:bg-purple-50' href='Coding/Haskell/Webapp-Example/MyService_Types.hs'>
Webapp-Example: MyService/Types.hs
</a>
<div class='mb-4 overflow-auto text-sm text-gray-500'>
<div class='pl-2 mt-2 border-l-2 border-purple-200 hover:border-purple-500'>
<div><p>Anleitung siehe <a href='Coding/Haskell/Webapp-Example' class='text-gray-600 font-bold hover:bg-gray-50' data-wikilink-type='WikiLinkTag'>Webapp-Development in Haskell</a>.</p></div>
</div>
</div>
</li>
<li>
<a class='text-purple-600 mavenLinkBold hover:bg-purple-50' href='Coding/Haskell/Webapp-Example/Main.hs'>
Webapp-Example: Main.hs
</a>
<div class='mb-4 overflow-auto text-sm text-gray-500'>
<div class='pl-2 mt-2 border-l-2 border-purple-200 hover:border-purple-500'>
<div><p>Wie man das verwendet, siehe <a href='Coding/Haskell/Webapp-Example' class='text-gray-600 font-bold hover:bg-gray-50' data-wikilink-type='WikiLinkTag'>Webapp-Development in Haskell</a>.</p></div>
</div>
</div>
</li>
<li>
<a class='text-purple-600 mavenLinkBold hover:bg-purple-50' href='Coding/OpenAPI'>
Openapi-generator
</a>
<div class='mb-4 overflow-auto text-sm text-gray-500'>
<div class='pl-2 mt-2 border-l-2 border-purple-200 hover:border-purple-500'>
<div><p>Wie im <a href='Coding/Haskell/Webapp-Example' class='text-gray-600 font-bold hover:bg-gray-50' data-wikilink-type='WikiLinkNormal'>Webapp-Development in Haskell</a> kurz angerissen wird in Haskell nicht zwischen Server und Client unterschieden. Daher können hier sehr viele Optimierungen bei Änderungen passieren, die in anderen Sprachen nicht so einfach möglich sind.</p></div>
</div>
</div>
</li>
</ul>
</div>
</div>
<section class='flex flex-wrap items-end justify-center my-4 space-x-2 space-y-2 font-mono text-sm'>
</section>
<!-- What goes in this file will at the very end of the main div -->
</main>
</div>
</div>
<footer class='flex items-center justify-center mt-2 mb-8 space-x-4 text-center text-gray-800'>
<div>
<a href='' title='Go to Home page'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-6 h-6 hover:text-purple-700' fill='none' viewBox='0 0 24 24' stroke='currentColor'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6'></path>
</svg>
</a>
</div>
<div>
<a href='-/all' title='View Index'>
<svg class='w-6 h-6 hover:text-purple-700' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 8V4m0 0h4M4 4l5 5m11-1V4m0 0h-4m4 0l-5 5M4 16v4m0 0h4m-4 0l5-5m11 5l-5-5m5 5v-4m0 4h-4'>
</path>
</svg>
</a>
</div>
<div>
<a href='https://emanote.srid.ca' target='_blank' title='Generated by Emanote 1.0.3.11'>
<img class='w-6 h-6 hover:text-purple-700' src='_emanote-static/emanote-logo.svg' />
</a>
</div>
<div>
<a href='-/tags' title='View tags'>
<svg class='w-6 h-6 hover:text-purple-700' fill='none' stroke='currentColor' viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M7 7h.01M7 3h5c.512 0 1.024.195 1.414.586l7 7a2 2 0 010 2.828l-7 7a2 2 0 01-2.828 0l-7-7A1.994 1.994 0 013 12V7a4 4 0 014-4z'>
</path>
</svg>
</a>
</div>
<div>
<a href='-/tasks' title='View tasks'>
<svg xmlns='http://www.w3.org/2000/svg' class='w-6 h-6 hover:text-purple-700' fill='none' viewBox='0 0 24 24' stroke='currentColor'>
<path stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z'></path>
</svg>
</a>
</div>
</footer>
</div>
<div id='stork-search-container' class='hidden fixed w-screen h-screen inset-0 backdrop-filter backdrop-blur-sm'>
<div class='fixed w-screen h-screen inset-0' onclick='window.emanote.stork.toggleSearch()'></div>
<div class='container mx-auto p-10 mt-10'>
<div class='stork-wrapper-flat container mx-auto'>
<input id='stork-search-input' data-stork='emanote-search' class='stork-input' placeholder='Search (Ctrl+K) ...' />
<div data-stork='emanote-search-output' class='stork-output'></div>
</div>
</div>
</div>
</body>
</html>