Merge pull request #17940 from github/use-redirects-file-instead-of-stubbed-archived-redirects

Use archived redirects.json files instead of stubbed redirect files

Author: sarahs

lib/enterprise-server-releases.js

@@ -47,8 +47,8 @@ const nextDeprecationDate = dates[oldestSupported].deprecationDate
 const isOldestReleaseDeprecated = new Date() > new Date(nextDeprecationDate)
 const deprecatedOnNewSite = deprecated.filter(version => versionSatisfiesRange(version, '>=2.13'))
 const firstVersionDeprecatedOnNewSite = '2.13'
-// starting from 2.18, we updated the archival script to create stubbed HTML redirect files
-const lastVersionWithoutStubbedRedirectFiles = '2.17'
+// starting from 2.18, we updated the archival script to create a redirects.json top-level file in the archived repo
+const lastVersionWithoutArchivedRedirectsFile = '2.17'
 // last version using paths like /enterprise/<release>/<user>/<product>/<category>/<article>
 // instead of /enterprise-server@<release>/<product>/<category>/<article>
 const lastReleaseWithLegacyFormat = '2.18'
@@ -68,7 +68,7 @@ module.exports = {
   deprecatedOnNewSite,
   dates,
   firstVersionDeprecatedOnNewSite,
-  lastVersionWithoutStubbedRedirectFiles,
+  lastVersionWithoutArchivedRedirectsFile,
   lastReleaseWithLegacyFormat,
   deprecatedReleasesWithLegacyFormat,
   deprecatedReleasesWithNewFormat,

middleware/archived-enterprise-versions.js

@@ -1,6 +1,6 @@
 const path = require('path')
 const slash = require('slash')
-const { firstVersionDeprecatedOnNewSite, lastVersionWithoutStubbedRedirectFiles } = require('../lib/enterprise-server-releases')
+const { firstVersionDeprecatedOnNewSite, lastVersionWithoutArchivedRedirectsFile } = require('../lib/enterprise-server-releases')
 const patterns = require('../lib/patterns')
 const versionSatisfiesRange = require('../lib/version-satisfies-range')
 const isArchivedVersion = require('../lib/is-archived-version')
@@ -25,21 +25,42 @@ module.exports = async (req, res, next) => {
   }
 
   // find redirects for versions between 2.13 and 2.17
-  // starting with 2.18, we updated the archival script to create stubbed HTML redirect files
+  // starting with 2.18, we updated the archival script to create a redirects.json file
   if (versionSatisfiesRange(requestedVersion, `>=${firstVersionDeprecatedOnNewSite}`) &&
-    versionSatisfiesRange(requestedVersion, `<=${lastVersionWithoutStubbedRedirectFiles}`)) {
+    versionSatisfiesRange(requestedVersion, `<=${lastVersionWithoutArchivedRedirectsFile}`)) {
     const redirect = archvivedRedirects[req.path]
     if (redirect && redirect !== req.path) {
       return res.redirect(301, redirect)
     }
   }
 
+  let reqPath = req.path
+  let isRedirect = false
+  if (versionSatisfiesRange(requestedVersion, `>${lastVersionWithoutArchivedRedirectsFile}`)) {
+    try {
+      const redirectJson = await got(getProxyPath('redirects.json', requestedVersion))
+
+      if (redirectJson[req.path]) {
+        isRedirect = true
+      }
+      reqPath = redirectJson[req.path] || req.path
+    } catch (err) {
+      // nooop
+    }
+  }
+
   try {
-    const r = await got(getProxyPath(req.path, requestedVersion))
+    const r = await got(getProxyPath(reqPath, requestedVersion))
     res.set('content-type', r.headers['content-type'])
     res.set('x-robots-tag', 'noindex')
 
-    // make the stubbed redirect files added in >=2.18 return 301 instead of 200
+    // make redirects found via redirects.json return 301 instead of 200
+    if (isRedirect) {
+      res.status(301)
+      res.set('location', reqPath)
+    }
+
+    // make stubbed redirect files (which exist in versions <2.13) return 301 instead of 200
     const staticRedirect = r.body.match(patterns.staticRedirect)
     if (staticRedirect) {
       res.status(301)
@@ -73,7 +94,7 @@ function getProxyPath (reqPath, requestedVersion) {
 // this workaround finds potentially relevant frontmatter redirects in currently supported pages
 function getFallbackRedirects (req, requestedVersion) {
   if (versionSatisfiesRange(requestedVersion, `<${firstVersionDeprecatedOnNewSite}`)) return
-  if (versionSatisfiesRange(requestedVersion, `>${lastVersionWithoutStubbedRedirectFiles}`)) return
+  if (versionSatisfiesRange(requestedVersion, `>${lastVersionWithoutArchivedRedirectsFile}`)) return
 
   return archivedFrontmatterFallbacks.find(arrayOfFallbacks => arrayOfFallbacks.includes(req.path))
 }

script/enterprise-server-deprecations/archive-version.js

@@ -9,7 +9,6 @@ const host = `http://localhost:${port}`
 const scrape = require('website-scraper')
 const program = require('commander')
 const rimraf = require('rimraf').sync
-const mkdirp = require('mkdirp').sync
 const version = require('../../lib/enterprise-server-releases').oldestSupported
 const archivalRepoName = 'help-docs-archived-enterprise-versions'
 const archivalRepoUrl = `https://github.com/github/${archivalRepoName}`
@@ -173,18 +172,20 @@ async function main () {
     console.log(`\n\ndone scraping! added files to ${path.relative(process.cwd(), finalDirectory)}\n`)
 
     // create redirect html files to preserve frontmatter redirects
-    await createRedirectPages(permalinksPerVersion, pageMap, finalDirectory)
+    await createRedirectsFile(permalinksPerVersion, pageMap, finalDirectory)
 
     console.log(`next step: deprecate ${version} in lib/enterprise-server-releases.js`)
 
     process.exit()
   })
 }
 
-async function createRedirectPages (permalinks, pageMap, finalDirectory) {
+async function createRedirectsFile (permalinks, pageMap, finalDirectory) {
   const pagesPerVersion = permalinks.map(permalink => pageMap[permalink])
   const redirects = await loadRedirects(pagesPerVersion, pageMap)
 
+  const redirectsPerVersion = {}
+
   Object.entries(redirects).forEach(([oldPath, newPath]) => {
     // remove any liquid variables that sneak in
     oldPath = oldPath
@@ -193,31 +194,8 @@ async function createRedirectPages (permalinks, pageMap, finalDirectory) {
     // ignore any old paths that are not in this version
     if (!(oldPath.includes(`/enterprise-server@${version}`) || oldPath.includes(`/enterprise/${version}`))) return
 
-    const fullPath = path.join(finalDirectory, oldPath)
-    const filename = `${fullPath}/index.html`
-    const html = getRedirectHtml(newPath)
-
-    mkdirp(fullPath)
-    fs.writeFileSync(filename, html)
+    redirectsPerVersion[oldPath] = newPath
   })
 
-  console.log('done creating redirect files!\n')
-}
-
-// redirect html files already exist in <=2.12 because these versions were deprecated on the old static site
-function getRedirectHtml (newPath) {
-  return `<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<title>Redirecting...</title>
-<link rel="canonical" href="${newPath}">
-<meta http-equiv="refresh" content="0; url=${newPath}">
-</head>
-<body>
-<h1>Redirecting...</h1>
-<a href="${newPath}">Click here if you are not redirected.</a>
-<script>location='${newPath}'</script>
-</body>
-</html>`
+  fs.writeFileSync(path.posix.join(finalDirectory, 'redirects.json'), JSON.stringify(redirectsPerVersion, null, 2))
 }

tests/routing/deprecated-enterprise-versions.js

@@ -30,6 +30,12 @@ describe('enterprise deprecation', () => {
     expect(res.headers.location).toBe('/en/enterprise/2.15/user/articles/viewing-contributions-on-your-profile')
   })
 
+  test('can access redirects from redirects.json in deprecated enterprise content >2.17', async () => {
+    const res = await get('/enterprise/2.19/admin/categories/time')
+    expect(res.statusCode).toBe(301)
+    expect(res.headers.location).toBe('/en/enterprise-server@2.19/admin/configuration/configuring-time-synchronization')
+  })
+
   test('handles requests for deprecated Enterprise pages ( >=2.13 )', async () => {
     expect(enterpriseServerReleases.deprecated.includes('2.13')).toBe(true)
     const $ = await getDOM('/en/enterprise/2.13/user/articles/about-branches')