use new static redirects file instead of precompiling on every server restart

Author: sarahs

lib/redirects/precompile.js

@@ -1,9 +1,6 @@
-const patterns = require('../patterns')
 const { latest } = require('../enterprise-server-releases')
-const getOldPathsFromPermalink = require('../redirects/get-old-paths-from-permalink')
 const getDocsPathFromDevPath = require('../redirects/get-docs-path-from-developer-path')
 const DEVELOPER_ROUTES = require('../redirects/static/developer-docs-routes-for-supported-versions')
-const ARCHIVED_ROUTES = require('../redirects/static/archived-routes-from-213-to-217')
 
 // This function runs at server warmup and precompiles possible redirect routes.
 // It outputs them in key-value pairs within a neat Javascript object: { oldPath: newPath }
@@ -14,26 +11,7 @@ module.exports = function precompileRedirects (pageList, pageMap) {
   // create backwards-compatible old paths for page permalinks and frontmatter redirects
   pageList.forEach(page => Object.assign(allRedirects, page.buildRedirects()))
 
-  // 2. REDIRECTS FOR ARCHIVED ROUTES FROM 2.13 TO 2.17
-  // Starting with 2.18, we updated the archival script to create stubbed HTML redirect files,
-  // so those files do the heavy lifting. The handling here is only for blanket redirects
-  // (like /articles -> /github) between 2.13 and 2.17. This works by creating possible
-  // old/incoming paths from the archived routes JSON. Frontmatter redirects were lost
-  // for 2.13-2.17, but the archived middleware tries to find fallbacks.
-  ARCHIVED_ROUTES.forEach(archivedRoute => {
-    const languageFromPath = archivedRoute.match(patterns.getLanguageCode)[1]
-    const versionFromPath = archivedRoute.match(patterns.getEnterpriseVersionNumber)[1]
-
-    // get an array of possible old paths, e.g., /desktop/guides/ from /desktop/
-    const possibleOldPaths = getOldPathsFromPermalink(archivedRoute, languageFromPath, versionFromPath)
-
-    // for each old path, add a redirect to the current route
-    possibleOldPaths.forEach(oldPath => {
-      allRedirects[oldPath] = archivedRoute
-    })
-  })
-
-  // 3. DEVELOPER ROUTES FOR CURRENTLY SUPPORTED VERSIONS
+  // 2. DEVELOPER ROUTES FOR CURRENTLY SUPPORTED VERSIONS
   // From the list of developer docs routes, create new docs.github.com-style paths.
   // Note that the list only includes supported enterprise paths up to 2.21, which is
   // the last version that was available on developer.github.com before the migration.

middleware/archived-enterprise-versions.js

@@ -6,6 +6,7 @@ const versionSatisfiesRange = require('../lib/version-satisfies-range')
 const isArchivedVersion = require('../lib/is-archived-version')
 const findPage = require('../lib/find-page')
 const got = require('got')
+const archvivedRedirects = require('../lib/redirects/static/archived-redirects-from-213-to-217')
 
 // This module handles requests for deprecated GitHub Enterprise versions
 // by routing them to static content in help-docs-archived-enterprise-versions
@@ -27,7 +28,7 @@ module.exports = async (req, res, next) => {
   // starting with 2.18, we updated the archival script to create stubbed HTML redirect files
   if (versionSatisfiesRange(requestedVersion, `>=${firstVersionDeprecatedOnNewSite}`) &&
     versionSatisfiesRange(requestedVersion, `<=${lastVersionWithoutStubbedRedirectFiles}`)) {
-    const redirect = req.context.redirects[req.path]
+    const redirect = archvivedRedirects[req.path]
     if (redirect && redirect !== req.path) {
       return res.redirect(301, redirect)
     }