More instructions + docker container link

config.js

@@ -1,9 +1,15 @@
 const env = process.env.APP__ENV_NAME || "local";
 const isLocal = env === "local" || env === "test";
+const strippedPath = process.env.APP__STRIPPED_PATH || '';
+
+console.log("Environment variables:");
+console.log(`APP__STRIPPED_PATH=${strippedPath} (path added to original host in analytics scripts)`);
+console.log(`APP__ENV_NAME=${env} (should not be local nor test in production)`);
 
 export default {
     isLocalEnv: isLocal,
     httpPort: process.env.PORT || 80,
+    strippedPath,
     proxyDomain: "",          // Domain to proxy calls through. Leave it empty to use the requested domain as a proxy domain
     proxy: {                  // Proxy configuration is here
         domains: [            // These domains are replaced in any proxied response (including scripts, URLs and redirects)
@@ -69,6 +75,7 @@ export default {
         },
         maskPaths: [ // Paths which are masked in URLs and redirects in order to avoid firing ad-blocking rules
             "/google-analytics",
+            "/www.google-analytics.com",
             "/adsbygoogle",
             "/googleads",
             "/log_event\\?",

package.json

@@ -5,7 +5,9 @@
   "module": "src/api.js",
   "scripts": {
     "test": "exit 0",
-    "start": "node -r esm src/api.js"
+    "start": "node -r esm src/api.js",
+    "mask": "node -r esm scripts.js mask",
+    "unmask": "node -r esm scripts.js unmask"
   },
   "keywords": [
     "proxy"

readme.md

@@ -43,15 +43,17 @@ Technically, NodeJS proxy API works as follows:
 
 ## Prerequisites
 
-In order to enable analytics proxying, you have to have some "DevOps" skills to perform the following:
+In order to enable analytics proxying, you have to perform some DevOps in your infrastructure. Assuming you're using microservices:
 
-1. Run a dedicated back end with proxy (NodeJS application in this repository).
-2. Enable forwarding of a particular path (for example, `/gtm-proxy/*`) on your domain to this back end.
-    1. It is important to use your own domain, as using centralized domains might appear at the ad-blocking databases.
-    2. Make sure you strip the prefix path before proxy, the request path `https://your-domain.com/gtm-proxy/www.google-analytics.com/analytics.js` should land as `/www.google-analytics.com/analytics.js` at the NodeJS proxy application (this repository), stripping `gtm-proxy/` from the URL.
+1. Run a dedicated back end (container) with proxy (NodeJS application / container in this repository) - see setup instructions below.
+2. Create forwarding rule from your front end to hit this back end.
+    1. For instance, proxy all calls requesting `/gtm-proxy/*` to this back end. You can either strip `/gtm-proxy` in your setup or make use of `APP__STRIPPED_PATH` env variable by specifying it to `/gtm-proxy`. Ultimately, the request path `https://your-domain.com/gtm-proxy/www.google-analytics.com/analytics.js` should land as `/www.google-analytics.com/analytics.js` at the NodeJS proxy application/container (this repository), stripping `/gtm-proxy` from the URL.
+    2. It is important to use your own domain, as using centralized domains might one day appear at the ad-blocking databases.
 3. **Modify your initial Google Tag Manager / Google Analytics script to request the proxied file**
-    1. Replace `https://www.googletagmanager.com/gtag/js?id=UA-123456-7` there to use `https://your-domain.com/gtm-proxy/www.googletagmanager.com/gtag/js?id=UA-123456-7` (or whatever path you've set up).
-    2. The [example](src/test-static/index.html) in this repository uses `/www.googletagmanager.com/gtm.js` (which is equivalent of `http://localhost/www.googletagmanager.com/gtm.js`).
+    1. Replace `https://www.googletagmanager.com/gtag/js?id=UA-123456-7` there to use `https://your-domain.com/gtm-proxy/www.googletagmanager.com/gtag/js?id=UA-123456-7` (or whatever path you've set up). Also, mask the URL by running `npm run mask <YOUR_URL>` in this repository so that ad-blockers won't block it right away.
+    2. For instance, if you run `npm run mask www.google-analytics.com/analytics.js`, you get this masked URL: `*(d3d3Lmdvb2dsZS1hbmFseXRpY3MuY29t)*/*(YW5hbHl0aWNzLmpz)*`. Use it in your script tag now: `<script src="/gtm-proxy/*(d3d3Lmdvb2dsZS1hbmFseXRpY3MuY29t)*/*(YW5hbHl0aWNzLmpz)*" async></script>`.
+    3. The [example](src/test-static/index.html) in this repository uses unmasked `/www.googletagmanager.com/gtm.js` (which is equivalent of `http://localhost/www.googletagmanager.com/gtm.js`).
+4. Test the thing!
 
 **This to consider before implementing the solution**:
 
@@ -61,6 +63,25 @@ In order to enable analytics proxying, you have to have some "DevOps" skills to
 
 ## Setup
 
+### In Docker
+
+The [light Docker container](https://hub.docker.com/r/zitros/analytics-saviour) of 41.5MB is available and ready to be run in your infrastructure.
+
+```bash
+docker pull zitros/analytics-saviour
+docker run -p 80:80 zitros/analytics-saviour
+# Now open http://localhost and check the proxy.
+```
+
+Available environment variables:
+
+```bash
+APP__STRIPPED_PATH=/gtm-proxy
+# A URL prefix to strip. If you didn't manage to remove this prefix in the request hitting the container, you can specify it here. 
+```
+
+### NodeJS Application
+
 To run the NodeJS application, simply clone the repository, navigate to its directory and run:
 
 ```bash
@@ -77,8 +98,6 @@ Proxied: www.google-analytics.com/collect?v=1&_v=j73&a=531530768&t=pageview&_s=1
 
 Check the [test-static/index.html](test-static/index.html) file's code to see how to bind the proxied analytics to your front end.
 
-Later, you can containerize this repository and route the incoming traffic to `/gtm-proxy` path (for example) through this container in order to avoid analytics blocking.
-
 ## Configuration 
 
 You can configure which third-parties to proxy/replace and how to do it in the config file. Find the actual configuration in [config.js](config.js) file:
@@ -114,7 +133,7 @@ You can configure which third-parties to proxy/replace and how to do it in the c
 
 ## License
 
-[MIT](LICENSE) © [Nikita Savchenko](https://nikita.tk)
+[MIT](LICENSE) © [Nikita Savchenko](https://nikita.tk/developer)
 
 ## Contributions
 

scripts.js

@@ -0,0 +1,28 @@
+import { mask, unmask } from './src/modules/mask';
+
+const command = process.argv[2];
+const args = process.argv.slice(3);
+
+const f = ({
+
+  "mask": (path) => {
+
+    if (typeof path !== 'string') {
+      console.log('Please provide an argument to mask');
+      return;
+    }
+    console.log(`Masking ${path}...`);
+    console.log('Masked URL:', mask(path));
+  },
+
+  "unmask": (path) => {
+    if (typeof path !== 'string') {
+      console.log('Please provide an argument to unmask');
+      return;
+    }
+    console.log('Unmasked URL:', unmask(path));
+  },
+
+})[command] || (() => console.log(`No script ${command}!`));
+
+f(...args);

src/api.js

@@ -48,7 +48,7 @@ export async function init () {
         });
 
         app.listen(config.httpPort, function onReady () {
-            info(`Web server is listening on port ${ config.httpPort }`);
+            info(`Analytics proxy web server is listening on port ${ config.httpPort }`);
             isReady = true;
         });
 

src/modules/proxy.js

@@ -16,12 +16,12 @@ const maskRegex = new RegExp(
     "gi"
 );
 const replaceDomainsForHost = (host) => (match, pos, str) => {
-    const escapedSlashes = str[pos - 2] === "\\" && str[pos - 2] === "/"
+    const escapedSlashes = str[pos - 2] === "\\" && str[pos - 2] === "/" // wat?
     const r = `${
         escapedSlashes
             ? (config.proxyDomain || host).replace(/\//g, "\\/") + "\\"
             : (config.proxyDomain || host)
-    }/${ match }`;
+    }${ config.strippedPath }/${ match }`;
     return r;
 };
 
@@ -37,19 +37,31 @@ export function createDefaultProxy (targetDomain, proxyOptionsOverride = {}) {
                 ? proxyOptionsOverride["proxyReqOptDecorator"](proxyRequest, originalRequest)
                 : proxyRequest;
         },
-        userResHeaderDecorator: (headers, { headers: { host } }) => {
-            if (headers.location) {
+        userResHeaderDecorator: (proxyHeaders, origninalHeaders) => {
+            const { headers: { host } } = origninalHeaders;
+            if (proxyHeaders.location) {
                 if (config.proxy.specialContentReplace[servername]) { // Keep before other replacements
                     const replacements = config.proxy.specialContentReplace[servername];
                     for (const r of replacements) {
-                        headers.location = headers.location.replace(r.regex, r.replace);
+                        proxyHeaders.location = proxyHeaders.location.replace(r.regex, r.replace);
                     }
                 }
-                headers.location = headers.location
+                proxyHeaders.location = proxyHeaders.location
                     .replace(replaceDomainRegex, replaceDomainsForHost(host))
                     .replace(maskRegex, match => mask(match));
             }
-            return headers;
+            // [
+            //     "user-agent",
+            //     "accept",
+            //     "accept-encoding",
+            //     "accept-language",
+            //     "cookie"
+            // ].forEach(prop => {
+            //     if (origninalHeaders.headers.hasOwnProperty(prop) && !proxyHeaders[prop]) {
+            //         proxyHeaders[prop] = origninalHeaders.headers[prop];
+            //     }
+            // });
+            return proxyHeaders;
         },
         userResDecorator: (_, proxyResData, { headers: { host } }) => {
             if (_.req.res && _.req.res.client && _.req.res.client.servername) {
@@ -84,8 +96,9 @@ export function createDefaultProxy (targetDomain, proxyOptionsOverride = {}) {
             ) {
 
                 const parsedUrl = url.parse(unmasked);
-                const clientIp = req.headers["x-forwarded-for"]
-                    ? req.headers["x-forwarded-for"].split(/,\s?/g)[0]
+                const pverwrittenIp = req.headers["x-forwarded-for"] || req.headers["x-real-ip"];
+                const clientIp = pverwrittenIp
+                    ? pverwrittenIp.split(/,\s?/g)[0]
                     : req.connection.remoteAddress.split(":").pop();
                 const encodedIp = encodeURIComponent(clientIp);
 

test-static/index.html

@@ -7,7 +7,7 @@
     <!-- Google Tag Manager Setup (a script which loads other analytics tools) -->
     <script>(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=
+    j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= // Don't forget to mask and replace the URL! npm run mask www.googletagmanager.com/gtm.js?id=ABCDEFG
     '/www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); // When you're done setting up URL forwarding, prefix /www.googletagmanager.com/... path with your proxy route (/gtm-proxy)
     })(window,document,'script','dataLayer','GTM-XXXXXXX');</script> <!-- Replace GTM-XXXXXXX with your tag -->
     <!-- End Google Tag Manager Setup -->
@@ -19,7 +19,8 @@
         ga('create', 'UA-98253329-1', 'auto'); // Replace UA-98253329-1 with your tag
         ga('send', 'pageview');
     </script>
-    <script src="/www.google-analytics.com/analytics.js" async></script> <!-- When you're done setting up URL forwarding, prefix /www.google-analytics.com/... path with your proxy route (/gtm-proxy) -->
+    <!-- Masked www.google-analytics.com/analytics.js is below -->
+    <script src="/*(d3d3Lmdvb2dsZS1hbmFseXRpY3MuY29t)*/*(YW5hbHl0aWNzLmpz)*" async></script> <!-- When you're done setting up URL forwarding, prefix /www.google-analytics.com/... path with your proxy route (/gtm-proxy) -->
     <!-- End Google Analytics Setup -->
 
 </head>