CDN: Adds support for serving assets over a CDN (#30691)

* CDN: Initial poc support for serving assets over a CDN

* Minor fix

* added build path and test

* fix lint error

* Added edition to cdn path

* Move master builds to a separate path

* Added error handling for the url parsing, changed setting name, and added docs

* Updated sample.ini

* Some property renames

* updated

* Minor update to html

* index template improvements

* Update docs/sources/administration/configuration.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/administration/configuration.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

* Added ContentDeliveryPrefix to Licence service

* updated docs

* Updated test mock

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

conf/defaults.ini

@@ -66,6 +66,9 @@ cert_key =
 # Unix socket path
 socket = /tmp/grafana.sock
 
+# CDN Url
+cdn_url =
+
 #################################### Database ############################
 [database]
 # You can configure the database connection by specifying type, host, name, user and password

conf/sample.ini

@@ -67,6 +67,9 @@
 # Unix socket path
 ;socket =
 
+# CDN Url
+;cdn_url =
+
 #################################### Database ####################################
 [database]
 # You can configure the database connection by specifying type, host, name, user and password

docs/sources/administration/configuration.md

@@ -259,6 +259,15 @@ Path to the certificate key file (if `protocol` is set to `https` or `h2`).
 
 Path where the socket should be created when `protocol=socket`. Make sure that Grafana has appropriate permissions before you change this setting.
 
+### cdn_url
+
+> **Note**: Available in Grafana v7.4 and later versions.
+
+Specify a full HTTP URL address to the root of your Grafana CDN assets. Grafana will add edition and version paths.
+
+For example, given a cdn url like `https://cdn.myserver.com` grafana will try to load a javascript file from
+`http://cdn.myserver.com/grafana-oss/v7.4.0/public/build/app.<hash>.js`.
+
 <hr />
 
 ## [database]

pkg/api/dtos/index.go

@@ -25,6 +25,7 @@ type IndexViewData struct {
 	AppleTouchIcon          template.URL
 	AppTitle                string
 	Sentry                  *setting.Sentry
+	ContentDeliveryURL      string
 	// Nonce is a cryptographic identifier for use with Content Security Policy.
 	Nonce string
 }

pkg/api/index.go

@@ -428,6 +428,7 @@ func (hs *HTTPServer) setIndexViewData(c *models.ReqContext) (*dtos.IndexViewDat
 		NavTree:                 navTree,
 		Sentry:                  &hs.Cfg.Sentry,
 		Nonce:                   c.RequestNonce,
+		ContentDeliveryURL:      hs.Cfg.GetContentDeliveryURL((hs.License.Edition())),
 	}
 
 	if setting.DisableGravatar {

pkg/models/licensing.go

@@ -13,6 +13,9 @@ type Licensing interface {
 	// Return edition
 	Edition() string
 
+	// Used to build content delivery URL
+	ContentDeliveryPrefix() string
+
 	LicenseURL(user *SignedInUser) string
 
 	StateInfo() string

pkg/plugins/backendplugin/manager_test.go

@@ -403,6 +403,10 @@ func (t *testLicensingService) StateInfo() string {
 	return ""
 }
 
+func (t *testLicensingService) ContentDeliveryPrefix() string {
+	return ""
+}
+
 func (t *testLicensingService) LicenseURL(user *models.SignedInUser) string {
 	return ""
 }

pkg/services/licensing/oss.go

@@ -32,6 +32,10 @@ func (*OSSLicensingService) StateInfo() string {
 	return ""
 }
 
+func (*OSSLicensingService) ContentDeliveryPrefix() string {
+	return "grafana-oss"
+}
+
 func (l *OSSLicensingService) LicenseURL(user *models.SignedInUser) string {
 	if user.IsGrafanaAdmin {
 		return l.Cfg.AppSubURL + "/admin/upgrading"

pkg/setting/setting.go

@@ -197,6 +197,7 @@ type Cfg struct {
 	SocketPath       string
 	RouterLogging    bool
 	Domain           string
+	CDNRootURL       *url.URL
 
 	// build
 	BuildVersion string
@@ -767,7 +768,7 @@ func (cfg *Cfg) Load(args *CommandLineArgs) error {
 	provisioning := valueAsString(iniFile.Section("paths"), "provisioning", "")
 	cfg.ProvisioningPath = makeAbsolute(provisioning, HomePath)
 
-	if err := readServerSettings(iniFile, cfg); err != nil {
+	if err := cfg.readServerSettings(iniFile); err != nil {
 		return err
 	}
 
@@ -1251,7 +1252,7 @@ func readSnapshotsSettings(cfg *Cfg, iniFile *ini.File) error {
 	return nil
 }
 
-func readServerSettings(iniFile *ini.File, cfg *Cfg) error {
+func (cfg *Cfg) readServerSettings(iniFile *ini.File) error {
 	server := iniFile.Section("server")
 	var err error
 	AppUrl, AppSubUrl, err = parseAppUrlAndSubUrl(server)
@@ -1263,8 +1264,8 @@ func readServerSettings(iniFile *ini.File, cfg *Cfg) error {
 	cfg.AppURL = AppUrl
 	cfg.AppSubURL = AppSubUrl
 	cfg.ServeFromSubPath = ServeFromSubPath
-
 	cfg.Protocol = HTTPScheme
+
 	protocolStr := valueAsString(server, "protocol", "http")
 
 	if protocolStr == "https" {
@@ -1297,9 +1298,34 @@ func readServerSettings(iniFile *ini.File, cfg *Cfg) error {
 		return err
 	}
 
+	cdnURL := valueAsString(server, "cdn_url", "")
+	if cdnURL != "" {
+		cfg.CDNRootURL, err = url.Parse(cdnURL)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
+// GetContentDeliveryURL returns full content delivery URL with /<edition>/<version> added to URL
+func (cfg *Cfg) GetContentDeliveryURL(prefix string) string {
+	if cfg.CDNRootURL != nil {
+		url := *cfg.CDNRootURL
+		preReleaseFolder := ""
+
+		if strings.Contains(cfg.BuildVersion, "pre") || strings.Contains(cfg.BuildVersion, "alpha") {
+			preReleaseFolder = "pre-releases"
+		}
+
+		url.Path = path.Join(url.Path, prefix, preReleaseFolder, cfg.BuildVersion)
+		return url.String()
+	}
+
+	return ""
+}
+
 func (cfg *Cfg) readDataSourcesSettings() {
 	datasources := cfg.Raw.Section("datasources")
 	cfg.DataSourceLimit = datasources.Key("datasource_limit").MustInt(5000)

pkg/setting/setting_test.go

@@ -2,6 +2,7 @@ package setting
 
 import (
 	"bufio"
+	"net/url"
 	"os"
 	"path"
 	"path/filepath"
@@ -389,3 +390,35 @@ func TestAuthDurationSettings(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, maxLifetimeDurationTest, cfg.LoginMaxLifetime)
 }
+
+func TestGetCDNPath(t *testing.T) {
+	var err error
+	cfg := NewCfg()
+	cfg.BuildVersion = "v7.5.0-11124"
+	cfg.CDNRootURL, err = url.Parse("http://cdn.grafana.com")
+	require.NoError(t, err)
+
+	require.Equal(t, "http://cdn.grafana.com/grafana-oss/v7.5.0-11124", cfg.GetContentDeliveryURL("grafana-oss"))
+	require.Equal(t, "http://cdn.grafana.com/grafana/v7.5.0-11124", cfg.GetContentDeliveryURL("grafana"))
+}
+
+func TestGetCDNPathWithPreReleaseVersionAndSubPath(t *testing.T) {
+	var err error
+	cfg := NewCfg()
+	cfg.BuildVersion = "v7.5.0-11124pre"
+	cfg.CDNRootURL, err = url.Parse("http://cdn.grafana.com/sub")
+	require.NoError(t, err)
+	require.Equal(t, "http://cdn.grafana.com/sub/grafana-oss/pre-releases/v7.5.0-11124pre", cfg.GetContentDeliveryURL("grafana-oss"))
+	require.Equal(t, "http://cdn.grafana.com/sub/grafana/pre-releases/v7.5.0-11124pre", cfg.GetContentDeliveryURL("grafana"))
+}
+
+// Adding a case for this in case we switch to proper semver version strings
+func TestGetCDNPathWithAlphaVersion(t *testing.T) {
+	var err error
+	cfg := NewCfg()
+	cfg.BuildVersion = "v7.5.0-alpha.11124"
+	cfg.CDNRootURL, err = url.Parse("http://cdn.grafana.com")
+	require.NoError(t, err)
+	require.Equal(t, "http://cdn.grafana.com/grafana-oss/pre-releases/v7.5.0-alpha.11124", cfg.GetContentDeliveryURL("grafana-oss"))
+	require.Equal(t, "http://cdn.grafana.com/grafana/pre-releases/v7.5.0-alpha.11124", cfg.GetContentDeliveryURL("grafana"))
+}

public/app/index.ts

-import app from './app';
+declare let __webpack_public_path__: string;
+
+/**
+ * Check if we are hosting files on cdn and set webpack public path
+ */
+if ((window as any).public_cdn_path) {
+  __webpack_public_path__ = (window as any).public_cdn_path;
+}
 
+import app from './app';
 app.initEchoSrv();
 app.init();

public/views/index-template.html

@@ -3,16 +3,15 @@
   <head>
     <script nonce="[[.Nonce]]">
       // https://github.com/GoogleChromeLabs/tti-polyfill
-      !(function() {
+      !(function () {
         if ('PerformanceLongTaskTiming' in window) {
           var g = (window.__tti = { e: [] });
-          g.o = new PerformanceObserver(function(l) {
+          g.o = new PerformanceObserver(function (l) {
             g.e = g.e.concat(l.getEntries());
           });
           g.o.observe({ entryTypes: ['longtask'] });
         }
       })();
-
     </script>
     <meta charset="utf-8" />
     <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
@@ -25,16 +24,15 @@
 
     <link
       rel="preload"
-      href="public/fonts/roboto/RxZJdnzeo3R5zSexge8UUVtXRa8TVwTICgirnJhmVJw.woff2"
+      href="[[.ContentDeliveryURL]]/public/fonts/roboto/RxZJdnzeo3R5zSexge8UUVtXRa8TVwTICgirnJhmVJw.woff2"
       as="font"
       crossorigin
     />
 
     <link rel="icon" type="image/png" href="[[.FavIcon]]" />
     <link rel="apple-touch-icon" sizes="180x180" href="[[.AppleTouchIcon]]" />
-    <link rel="mask-icon" href="public/img/grafana_mask_icon.svg" color="#F05A28" />
-
-    <link rel="stylesheet" href="public/build/grafana.[[ .Theme ]].<%= webpack.hash %>.css" />
+    <link rel="mask-icon" href="[[.ContentDeliveryURL]]/public/img/grafana_mask_icon.svg" color="#F05A28" />
+    <link rel="stylesheet" href="[[.ContentDeliveryURL]]/public/build/grafana.[[ .Theme ]].<%= webpack.hash %>.css" />
 
     <script nonce="[[.Nonce]]">
       performance.mark('css done blocking');
@@ -199,14 +197,17 @@
         </p>
         <p>
           1. This could be caused by your reverse proxy settings.<br /><br />
-          2. If you host grafana under subpath make sure your grafana.ini root_url setting includes subpath. If not using a reverse proxy make sure to set serve_from_sub_path to true.<br />
+          2. If you host grafana under subpath make sure your grafana.ini root_url setting includes subpath. If not
+          using a reverse proxy make sure to set serve_from_sub_path to true.<br />
           <br />
           3. If you have a local dev build make sure you build frontend using: yarn start, yarn start:hot, or yarn
           build<br />
           <br />
           4. Sometimes restarting grafana-server can help<br />
           <br />
-          5. You might be using a non-supported browser. To make sure read the documentation on <a href="https://grafana.com/docs/grafana/latest/installation/requirements/#supported-web-browsers">supported browsers</a>.
+          5. Check if you are using a non-supported browser. For more information, refer to the list of <a 
+            href="https://grafana.com/docs/grafana/latest/installation/requirements/#supported-web-browsers">
+            supported browsers</a>.
         </p>
       </div>
     </div>
@@ -217,7 +218,7 @@
       <search-wrapper></search-wrapper>
 
       <div class="main-view">
-				<div ng-view class="scroll-canvas"></div>
+        <div ng-view class="scroll-canvas"></div>
       </div>
     </grafana-app>
 
@@ -235,57 +236,64 @@
             preloader[0].className = "preloader preloader--done";
           }
         };
+
+        window.public_cdn_path = '[[.ContentDeliveryURL]]/public/build/';
     </script>
 
     [[if .GoogleTagManagerId]]
-    <!-- Google Tag Manager -->
-    <script nonce="[[.Nonce]]">
-      dataLayer = [
-        {
-          IsSignedIn: '[[.User.IsSignedIn]]',
-          Email: '[[.User.Email]]',
-          Name: '[[.User.Name]]',
-          UserId: '[[.User.Id]]',
-          OrgId: '[[.User.OrgId]]',
-          OrgName: '[[.User.OrgName]]',
-        },
-      ];
-    </script>
-    <noscript>
-      <iframe
-        src="//www.googletagmanager.com/ns.html?id=[[.GoogleTagManagerId]]"
-        height="0"
-        width="0"
-        style="display:none;visibility:hidden"
-      ></iframe>
-    </noscript>
-    <script nonce="[[.Nonce]]">
-      (function(w, d, s, l, i) {
-        w[l] = w[l] || [];
-        w[l].push({ 'gtm.start': new Date().getTime(), event: 'gtm.js' });
-        var f = d.getElementsByTagName(s)[0],
-          j = d.createElement(s),
-          dl = l != 'dataLayer' ? '&l=' + l : '';
-        j.async = true;
-        j.src = '//www.googletagmanager.com/gtm.js?id=' + i + dl;
-        f.parentNode.insertBefore(j, f);
-      })(window, document, 'script', 'dataLayer', '[[.GoogleTagManagerId]]');
-    </script>
-    <!-- End Google Tag Manager -->
-    [[end]]
+      <!-- Google Tag Manager -->
+      <script nonce="[[.Nonce]]">
+        dataLayer = [
+          {
+            IsSignedIn: '[[.User.IsSignedIn]]',
+            Email: '[[.User.Email]]',
+            Name: '[[.User.Name]]',
+            UserId: '[[.User.Id]]',
+            OrgId: '[[.User.OrgId]]',
+            OrgName: '[[.User.OrgName]]',
+          },
+        ];
+      </script>
+      <noscript>
+        <iframe
+          src="//www.googletagmanager.com/ns.html?id=[[.GoogleTagManagerId]]"
+          height="0"
+          width="0"
+          style="display: none; visibility: hidden"
+        ></iframe>
+      </noscript>
+      <script nonce="[[.Nonce]]">
+        (function (w, d, s, l, i) {
+          w[l] = w[l] || [];
+          w[l].push({ 'gtm.start': new Date().getTime(), event: 'gtm.js' });
+          var f = d.getElementsByTagName(s)[0],
+            j = d.createElement(s),
+            dl = l != 'dataLayer' ? '&l=' + l : '';
+          j.async = true;
+          j.src = '//www.googletagmanager.com/gtm.js?id=' + i + dl;
+          f.parentNode.insertBefore(j, f);
+        })(window, document, 'script', 'dataLayer', '[[.GoogleTagManagerId]]');
+      </script>
+      <!-- End Google Tag Manager -->
+    [[end]] 
 
-    <%
-    for (key in htmlWebpackPlugin.files.chunks) { %><%
-      if (htmlWebpackPlugin.files.jsIntegrity) { %>
-    <script nonce="[[.Nonce]]"
-      src="<%= htmlWebpackPlugin.files.chunks[key].entry %>"
-      type="text/javascript"
-      integrity="<%= htmlWebpackPlugin.files.jsIntegrity[htmlWebpackPlugin.files.js.indexOf(htmlWebpackPlugin.files.chunks[key].entry)] %>"
-      crossorigin="<%= webpackConfig.output.crossOriginLoading %>"></script><%
-      } else { %>
-    <script nonce="[[.Nonce]]" src="<%= htmlWebpackPlugin.files.chunks[key].entry %>" type="text/javascript"></script><%
-      } %><%
-    } %>
+    <% for (key in htmlWebpackPlugin.files.chunks) { %>
+      <% if (htmlWebpackPlugin.files.jsIntegrity) { %>
+        <script
+          nonce="[[.Nonce]]"
+          src="[[.ContentDeliveryURL]]/<%= htmlWebpackPlugin.files.chunks[key].entry %>"
+          type="text/javascript"
+          integrity="<%= htmlWebpackPlugin.files.jsIntegrity[htmlWebpackPlugin.files.js.indexOf(htmlWebpackPlugin.files.chunks[key].entry)] %>"
+          crossorigin="<%= webpackConfig.output.crossOriginLoading %>">
+        </script>
+      <% } else { %>
+        <script
+          nonce="[[.Nonce]]"
+          src="[[.ContentDeliveryURL]]/<%= htmlWebpackPlugin.files.chunks[key].entry %>"
+          type="text/javascript">
+        </script>
+      <% } %>
+    <% } %>
     <script nonce="[[.Nonce]]">
       performance.mark('js done blocking');
     </script>