deployment: set cache headers (#1036)

package.json

@@ -8,7 +8,7 @@
     "debug": "node --inspect-brk server.js",
     "build": "next build",
     "test": "jest",
-    "start": "NODE_ENV=production node server.js",
+    "start": "./scripts/clear-cloudflare-cache.js; NODE_ENV=production node server.js",
     "format-staged": "pretty-quick --staged --no-restage --bail",
     "format-check": "prettier --check '{.,pages/**,public/static/docs/**,src/**}/*.{js,md,json}'",
     "lint-check": "eslint --ext .json,.js src pages",

scripts/clear-cloudflare-cache.js

@@ -0,0 +1,49 @@
+#!/usr/bin/env node
+/* global process */
+
+// This script runs just before the app starts. If we are running the
+// production heroku app (the only one with the below env variables)
+// the cache gets cleared.
+//
+// To clear the cache yourself, you can use the button in the
+// cloudflare dashboard ("Caching tab > Purge everything"), or run
+// this script with the required environment variables:
+//
+// - CLOUDFLARE_TOKEN: a token with the "Zone.Cache Purge" permission.
+// You can generate this token in "My Profile > API Tokens"
+//
+// - CLOUDFLARE_ZONE_ID: The zone ID to purge. You can find it in the
+// sidebar of the "overview" tab for dvc.org
+
+const fetch = require('isomorphic-fetch');
+
+const { CLOUDFLARE_TOKEN, CLOUDFLARE_ZONE_ID } = process.env;
+
+async function main() {
+  const res = await fetch(
+    `https://api.cloudflare.com/client/v4/zones/${CLOUDFLARE_ZONE_ID}/purge_cache`,
+    {
+      method: 'POST',
+      headers: {
+        authorization: `Bearer ${CLOUDFLARE_TOKEN}`,
+        'content-type': 'application/json'
+      },
+      body: JSON.stringify({ purge_everything: true })
+    }
+  );
+
+  const body = await res.text();
+
+  if (!res.ok) {
+    throw new Error('Error response received from CloudFlare: ' + body);
+  }
+
+  console.log('Cleared cache successfully');
+}
+
+if (CLOUDFLARE_TOKEN) {
+  main().catch(e => {
+    console.error(e);
+    process.exit(1);
+  });
+}

scripts/exclude-links.txt

@@ -8,6 +8,7 @@ https://accounts.google.com/o/oauth2/auth
 https://api.github.com/repos/$
 https://blog.$
 https://circleci.com/gh/iterative/dvc.org
+https://api.cloudflare.com/client/v4/zones/$
 https://code.dvc.org/foo/bar
 https://data.dvc.org/foo/bar
 https://discuss.$

server.js

@@ -28,10 +28,13 @@ app.prepare().then(() => {
     const { pathname, query } = parsedUrl
     const host = req.headers.host
 
+    res.setHeader('Cache-Control', 'public, max-age=0, s-maxage=99999')
+
     let [redirectCode, redirectLocation] = getRedirect(host, pathname, {
       req,
       dev
     })
+
     if (redirectLocation) {
       // HTTP redirects
 
@@ -40,7 +43,6 @@ app.prepare().then(() => {
         redirectLocation += '?' + queryStr
       }
       res.writeHead(redirectCode, {
-        'Cache-control': 'no-cache',
         Location: redirectLocation
       })
       res.end()