index.js

// Packages
const Metalsmith       = require('metalsmith');
const markdown         = require('metalsmith-markdownit');
const layouts          = require('metalsmith-layouts');
const permalinks       = require('metalsmith-permalinks');
const assets           = require('metalsmith-assets');
const dataLoader       = require('metalsmith-data-loader');
const watch            = require('metalsmith-watch');
const branch           = require('metalsmith-branch')
const serve            = require('metalsmith-serve');
const redirect         = require('metalsmith-redirect');
const webpack          = require('metalsmith-webpack2');
const anchor           = require('markdown-it-anchor');
const attrs            = require('markdown-it-attrs');
const timer            = require('metalsmith-timer');
const ignore           = require('metalsmith-ignore');

// Local Plugins
const reduce                  = require('./plugins/metalsmith-revision').reduce;
const restore                 = require('./plugins/metalsmith-revision').restore;
const hierarchy               = require('./plugins/metalsmith-hierarchy');
const hierarchyRss            = require('./plugins/metalsmith-hierarchy-rss');
const headings                = require('./plugins/metalsmith-headings');
const algolia                 = require('./plugins/metalsmith-algolia');
const inPlace                 = require('./plugins/metalsmith-in-place-dcos');
const includeContent          = require('./plugins/metalsmith-include-content-dcos');
const shortcodes              = require('./plugins/metalsmith-shortcodes');
const wkhtmltopdfLinkResolver = require('./plugins/metalsmith-wkhtmltopdf-link-resolver');

// Configs
const shortcodesConfig = require('./shortcodes');

function splitCommasOrEmptyArray(val) {
  return (val && val.length > 0) ? val.split(',') : [];
}

// Environment Variables
const GIT_BRANCH = process.env.GIT_BRANCH;
const ALGOLIA_UPDATE = process.env.ALGOLIA_UPDATE;
const ALGOLIA_PROJECT_ID = process.env.ALGOLIA_PROJECT_ID;
const ALGOLIA_PUBLIC_KEY = process.env.ALGOLIA_PUBLIC_KEY;
const ALGOLIA_PRIVATE_KEY = process.env.ALGOLIA_PRIVATE_KEY;
const ALGOLIA_INDEX = process.env.ALGOLIA_INDEX;
const ALGOLIA_CLEAR_INDEX = process.env.ALGOLIA_CLEAR_INDEX;
const RENDER_PATH_PATTERN = process.env.RENDER_PATH_PATTERN;
const ALGOLIA_SKIP_SECTIONS = splitCommasOrEmptyArray(process.env.ALGOLIA_SKIP_SECTIONS);
const METALSMITH_SKIP_SECTIONS = splitCommasOrEmptyArray(process.env.METALSMITH_SKIP_SECTIONS);

//
// Errors
//

if (!GIT_BRANCH && process.env.NODE_ENV !== 'development') {
  throw new Error('Env var GIT_BRANCH has not been set.');
}

if (ALGOLIA_UPDATE === 'true') {
  if (process.env.NODE_ENV === 'pdf') {
    throw new Error('Algolia env vars set while build env is pdf');
  }
  if (!ALGOLIA_PROJECT_ID) {
    throw new Error('Env var ALGOLIA_PROJECT_ID has not been set.');
  }
  if (!ALGOLIA_PUBLIC_KEY) {
    throw new Error('Env var ALGOLIA_PUBLIC_KEY has not been set.');
  }
  if (!ALGOLIA_PRIVATE_KEY) {
    throw new Error('Env var ALGOLIA_PRIVATE_KEY has not been set.');
  }
  if (!ALGOLIA_INDEX) {
    throw new Error('Env var ALGOLIA_INDEX has not been set.');
  }
}

//
// Metalsmith
//

const MS = Metalsmith(__dirname);

const currentYear = (new Date()).getFullYear();

// Metadata
// These are available in the layouts as js variables
MS.metadata({
  url: 'https://docs.mesosphere.com',
  siteTitle: 'Mesosphere DC/OS Documentation',
  siteDescription: 'Welcome to the DC/OS documentation. The DC/OS documentation ' +
  'can help you set up, learn about the system, and get your applications and' +
  ' workloads running on DC/OS.',
  copyright: `© ${currentYear} Mesosphere, Inc. All rights reserved.`,
  env: process.env.NODE_ENV,
  gitBranch: GIT_BRANCH,
  dcosDocsLatest: '1.11',
});

// Source
// Where metalsmith looks for all files
MS.source('./pages');

// Destination
// Where metalsmith will put the output code
MS.destination('./build');

// Don't Clean
// Cleaning removes the destination directory before writing to it
// I imagine cleaning makes watching take a long time, but untested for now
MS.clean(false);

//
// Content Branch Pipeline
//

const CB = branch();

// Start timer
CB.use(timer('CB: Init'));

CB.use(ignore(METALSMITH_SKIP_SECTIONS));
CB.use(timer('CB: Ignore'));

// Load model data from external .json/.yaml files
// For example (in your Front Matter):
//   model: path/to/my.yml (access content in my.yml as model.foo.bar)
// Can also specify multiple named models:
//   model:
//     data1: path/to/my.json (access content in my.json as model.data1.foo.bar)
//     data2: path/to/my.yml (access content in my.yml as model.data2.foo.bar)
CB.use(dataLoader({
  dataProperty: 'model',
  // Only enable in service pages for now.
  match: 'services/**/*.md',
}));
CB.use(timer('CB: Dataloader'));

// Load raw content via '#include' directives before rendering any mustache or markdown.
// For example (in your content):
//   #include path/to/file.tmpl
CB.use(includeContent({
  // Style as a C-like include statement. Must be on its own line.
  pattern: '^#include ([^ \n]+)$',
  // Only enable in service pages for now.
  match: 'services/**/*.md*',
}));
CB.use(timer('CB: IncludeContent'));

// Process any mustache templating in files.
// For example (in your Front Matter):
//   render: mustache
CB.use(inPlace({
  renderProperty: 'render',
  // Only enable in service pages for now.
  match: 'services/**/*.md',
}));
CB.use(timer('CB: Mustache'));

// Folder Hierarchy
CB.use(hierarchy({
  files: ['.md'],
  excerpt: true,
}));
CB.use(timer('CB: Hierarchy'));

// RSS Feed
CB.use(hierarchyRss({
  itemOptionsMap: {
    title: 'title',
    description: 'excerpt',
  },
}));
CB.use(timer('CB: Hierarchy RSS'));

// Filter unmodified files
if (process.env.NODE_ENV === 'development') {
  CB.use(reduce());
  CB.use(timer('CB: Reduce'));
}

//
// Slow Plugins
//

// Shortcodes
CB.use(shortcodes({
  files: ['.md'],
  shortcodes: shortcodesConfig,
}));
CB.use(timer('CB: Shortcodes'));

// Markdown
CB.use(markdown(
  {
    smartList: false,
    typographer: true,
    html: true,
  })
  .use(anchor, {
    permalink: true,
    renderPermalink: (slug, opts, state, idx) => {
      const linkTokens = [
        Object.assign(new state.Token('link_open', 'a', 1), {
          attrs: [
            ['class', opts.permalinkClass],
            ['href', opts.permalinkHref(slug, state)],
            ['aria-hidden', 'true'],
          ],
        }),
        Object.assign(new state.Token('html_block', '', 0), { content: opts.permalinkSymbol }),
        new state.Token('link_close', 'a', -1),
      ];
      state.tokens[idx + 1].children.unshift(...linkTokens);
    },
    permalinkClass: 'content__anchor',
    permalinkSymbol: '<i data-feather="bookmark"></i>',
    permalinkBefore: true,
  })
  .use(attrs),
);
CB.use(timer('CB: Markdown'));

// Headings
CB.use(headings());
CB.use(timer('CB: Headings'));

CB.use(redirect({
  '/support': 'https://support.mesosphere.com',
}));
CB.use(timer('CB: Redirects'));

// Permalinks
CB.use(permalinks());
CB.use(timer('CB: Permalinks'));

// Layouts
if (!RENDER_PATH_PATTERN) {
  // Default: Render all pages.
  CB.use(layouts({
    engine: 'pug',
    cache: true,
  }));
} else {
  // Dev optimization: Only render within a specific path (much faster turnaround)
  // For example, 'services/beta-cassandra/latest/**'
  CB.use(layouts({
    engine: 'pug',
    pattern: RENDER_PATH_PATTERN,
    cache: true,
  }));
}
CB.use(timer('CB: Layouts'));

//
// Slow Plugins End
//

// Restore unmodified files
if (process.env.NODE_ENV === 'development') {
  CB.use(restore());
  CB.use(timer('CB: Reduce'));
}

// The expected pattern format doesn't work with regex
let pathPatternRegex;
if (RENDER_PATH_PATTERN) {
  pathPatternRegex = RENDER_PATH_PATTERN.split('/').slice(0, -1).join("\/");
}

// Search Indexing
if (ALGOLIA_UPDATE === 'true') {
  CB.use(algolia({
    projectId: ALGOLIA_PROJECT_ID,
    privateKey: ALGOLIA_PRIVATE_KEY,
    index: ALGOLIA_INDEX,
    clearIndex: (ALGOLIA_CLEAR_INDEX !== undefined) ? (ALGOLIA_CLEAR_INDEX === 'true') : true,
    skipSections: ALGOLIA_SKIP_SECTIONS,
    renderPathPattern: pathPatternRegex,
  }));
  CB.use(timer('CB: Algolia'));
}

// Enable watching
// The keys represent the files to watch, the values are the files that will
// be updated. ONLY the files that are being updated will be accessible to
// during the rebuild. We must include everything at this point or the
// templates will not be accessible. Need changes to fix this.

// Can only watch with a RENDER_PATH_PATTERN because there are too many
// files without it.
if (process.env.NODE_ENV === 'development' && RENDER_PATH_PATTERN) {
  CB.use(watch({
    paths: {
      [`pages/${RENDER_PATH_PATTERN}/*`]: '**/*.{md,tmpl}',
      'layouts/**/*': '**/*.pug',
    },
  }));
  CB.use(timer('CB: Watch'));
}

// WkhtmltopdfLinkResolver
if (process.env.NODE_ENV === 'pdf') {
  CB.use(wkhtmltopdfLinkResolver({
    prefix: '/tmp/pdf/build',
  }));
  CB.use(timer('CB: WkhtmltopdfLinkResolver'));
}

// Serve
if (process.env.NODE_ENV === 'development') {
  CB.use(serve({
    port: 3000,
  }));
  CB.use(timer('CB: Webserver'));
}

//
// Assets Branch
//

const AB = branch();

// Start timer
AB.use(timer('AB: Init'));

// Watch
// Can only watch with a RENDER_PATH_PATTERN because there are too many
// files without it.
if (process.env.NODE_ENV === 'development' && RENDER_PATH_PATTERN) {
  AB.use(watch({
    paths: {
      'js/**/*': '**/*.js',
      'scss/**/*': '**/*.scss',
    },
  }));
  AB.use(timer('AB: Watch'));
}

// Assets
AB.use(assets({
  source: 'assets',
  destination: 'assets',
}));
AB.use(timer('AB: Assets'));

// Webpack
AB.use(webpack('./webpack.config.js'));
AB.use(timer('AB: Webpack'));

//
// Metalsmith
//

MS.use(CB);
MS.use(AB);

// Build
MS.build((err, files) => {
  if (err) throw err;
});