Refactor nginx.conf for simplicity, IP forwarding, and high concurrency

.gitignore

@@ -0,0 +1,27 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Nginx temp files
+client_body_temp
+proxy_temp
+fastcgi_temp
+uwsgi_temp
+scgi_temp
+
+# OS
+.DS_Store
+
+# Env files
+.env
+.env.*
+
+# Docker overrides
+docker-compose.override.yml
+
+# Editors/IDEs
+.vscode/
+.idea/

README.md

@@ -1,94 +1,36 @@
-# Nginx Proxy for Mixpanel
-An example nginx config that serves as a proxy to Mixpanel's Ingestion API and JavaScript library endpoints. To learn more, visit our [docs on Tracking via Proxy](https://docs.mixpanel.com/docs/tracking/how-tos/tracking-via-proxy).
+# 🚀 Mixpanel Tracking Proxy
 
+A lightweight nginx-based HTTP proxy server for Mixpanel tracking API, forked and customized for enhanced tracking capabilities. 📊
 
-## Installation
+## 📋 Overview
 
-There are a few ways you can use this repo to deploy a server that can be use to proxy Mixpanel API requests: 
+This proxy acts as an intermediary between client applications and Mixpanel's API endpoints, enabling:
 
-1. **one-click deploy** to your cloud provider
-2. **build a docker image** and run it on your own servers
-3. **copy and paste** the nginx settings to your existing nginx config file
+- **🎯 Tracking API Proxy**: Forwards requests to `api.mixpanel.com` with proper header management
+- **📚 JavaScript Library Proxy**: Serves Mixpanel's client libraries via `/lib.js` and `/lib.min.js`
+- **🔀 Decision API Proxy**: Handles feature flag requests via `/decide` endpoint
+- **🌍 IP Preservation**: Maintains accurate geolocation tracking through sophisticated IP forwarding
+- **🌐 Multi-Region Support**: Configurable for EU and IN data residency requirements
 
-### Option 1: One-Click Deploy
-click on a button below to deploy to your favorite cloud provider:
-
-[![Google Cloud Btn]][Google Cloud Deploy]
-[<img src=https://www.deploytodo.com/do-btn-blue.svg width=198px />][Digital Ocean Deploy]
-[![Railway Btn]][Railway Deploy]
-[![Render Btn]][Render Deploy]
-
-
-<!-- URLS -->
-[Google Cloud Btn]: https://binbashbanana.github.io/deploy-buttons/buttons/remade/googlecloud.svg
-[Google Cloud Deploy]: https://deploy.cloud.run
-
-[Digital Ocean Btn]: https://www.deploytodo.com/do-btn-blue.svg
-[Digital Ocean Deploy]: https://cloud.digitalocean.com/apps/new?repo=https://github.com/mixpanel/tracking-proxy/tree/master
-
-[Railway Btn]: https://binbashbanana.github.io/deploy-buttons/buttons/remade/railway.svg
-[Railway Deploy]: https://railway.app/template/_RaWSW
-
-[Render Btn]: https://binbashbanana.github.io/deploy-buttons/buttons/remade/render.svg
-[Render Deploy]: https://render.com/deploy?repo=https://github.com/mixpanel/tracking-proxy
-
-
-<!-- Maybe later? -->
-
-<!-- Heroku's app.json conflicts with GCP 0_o  -->
-[Heroku Btn]: https://binbashbanana.github.io/deploy-buttons/buttons/remade/heroku.svg
-[Heroku Deploy]: https://heroku.com/deploy/?template=https://github.com/mixpanel/tracking-proxy
-
-<!-- Azure is too... complicated -->
-[Azure Btn]: https://binbashbanana.github.io/deploy-buttons/buttons/remade/azure.svg
-[Azure Deploy]: https://portal.azure.com/#create/Microsoft.Template/uri/https%3A%2F%2Fraw.githubusercontent.com%2FYOUR_GITHUB_USERNAME%2FYOUR_REPO_NAME%2FYOUR_BRANCH_NAME%2Fpath%2Fto%2Fazuredeploy.json
-
-
-
-
-### Option 2: Docker Image
-   Assuming you have Docker installed on your system, you can do the following:
-
-   1. Clone the repo 
-   `git clone https://github.com/mixpanel/tracking-proxy`
-   2. Build the Docker image: 
-   `docker build -t mixpanel-proxy .`
-   3. Run a container using the image: 
-   `docker run --name my-tracking-proxy -d -p 8080:80 mixpanel-proxy`
-   4. Visit 
-   `http://localhost:8080`
-
-You should see:
-
-```json
-{
-  "error": "Welcome. Get started with our API by visiting https://developer.mixpanel.com/"
-}
-```
-This is same response you would get from visiting https://api.mixpanel.com/ (which means your proxy is working as expected).
-
-You can also verify the nginx config on the command line:
+## ⚡ Quick Start
 
+### 🐳 Docker Deployment
 ```bash
-nginx -t -c /etc/nginx/nginx.conf
+docker build -t mixpanel-proxy .
+docker run -p 8080:80 mixpanel-proxy
 ```
-
-For production, you would deploy this docker image to whatever servers you run your production services on.
-
-### Option 3: Add locations to your existing Nginx config
-If you already have servers running nginx, you can copy and paste the locations from the [nginx.conf](https://github.com/mixpanel/tracking-proxy/blob/master/nginx.conf) file in this repo and adjust the locations to match your preference.
-
-### Additional Configuration
-In case you see events tracked to your project, but geo-location properties are not being added correctly, there's likely a configuration issue with passing the IP address through the headers. Within the [nginx configuration]([url](https://github.com/mixpanel/tracking-proxy/blob/2c08e999d4b38aa943fad55884bcfe0ef72bb681/nginx.conf#L31)), by default, we leverage `$http_x_forwarded_for` and pass it through the `X-Real-IP` header to forward the IP from the original client; in some providers, this is not available and you will want to review which header/variable provides the IP address from the client. As an example, in Cloudflare, you need to pass `$realip_remote_addr` instead. You'll want to review the option that applies to your cloud provider.
-
-When you're seeing events ingested into Mixpanel, but no geo-location data included as properties (you don't see the mp_country_code property created, for example), one more aspect to check is if the query string param/value `ip=1` is being passed to our ingestion endpoint. Our client-side libraries, by default (unless you've disabled geo-location tracking), will append `ip=1` to the URL of the ingestion endpoint to indicate we should parse geo-location from the IP address of the incoming request. In some setups, this param might not be included in the request from the proxy, so it's also an aspect to check in this situation.
 
-### EU Residency
-This proxy server resolves requests to `api.mixpanel.com`, which points to Mixpanel's primary data centers in the United States. If you are using Mixpanel's **[EU Data Residency](https://docs.mixpanel.com/docs/other-bits/privacy-and-security/eu-residency)**, you will need to change the [nginx.config](https://github.com/mixpanel/tracking-proxy/blob/master/nginx.conf#L34) from `api.mixpanel.com` to `api-eu.mixpanel.com`
+### ⚙️ Configuration
+The nginx configuration includes:
+- ☁️ Cloudflare and Render.com IP range support
+- 🐛 Debug headers for troubleshooting
+- ⚡ High-performance settings with connection backlog optimization
 
-### IN Residency
-This proxy server resolves requests to `api.mixpanel.com`, which points to Mixpanel's primary data centers in the United States. If you are using Mixpanel's **[IN Data Residency](https://docs.mixpanel.com/docs/privacy/in-residency)**, you will need to change the [nginx.config](https://github.com/mixpanel/tracking-proxy/blob/master/nginx.conf#L34) from `api.mixpanel.com` to `api-in.mixpanel.com`
+## ✨ Features
 
-### Load Testing
+- **🔍 Client IP Preservation**: Advanced IP detection and forwarding logic
+- **📝 Debug Logging**: Comprehensive request debugging capabilities  
+- **⚖️ Load Balancing Ready**: Optimized for high-concurrency environments
+- **☁️ Cloud Provider Agnostic**: Works across different hosting platforms
 
-If you wish to load test your proxy, see **[mp-proxy-load-test](https://github.com/ak--47/mp-proxy-load-test/)** for a load testing script with artillery.
+🍴 Forked from the original Mixpanel tracking proxy with enhanced debugging and IP handling capabilities.

nginx.conf

@@ -1,6 +1,15 @@
-events {}
+worker_processes auto;
+
+events {
+    worker_connections 65536;
+    multi_accept on;
+}
+
 http {
-    # Cloudflare real IP configuration
+    server_tokens off;
+
+    # --- Real client IP handling (Cloudflare + Render) ---
+    # Trust Cloudflare edge networks so we can accept their headers as truth
     set_real_ip_from 173.245.48.0/20;
     set_real_ip_from 103.21.244.0/22;
     set_real_ip_from 141.101.64.0/18;
@@ -11,66 +20,69 @@ http {
     set_real_ip_from 162.158.0.0/15;
     set_real_ip_from 104.16.0.0/13;
     set_real_ip_from 172.64.0.0/13;
-    # Render.com internal IPs (10.223.x.x range)
+
+    # Trust Render's internal proxy network (requests may traverse it)
     set_real_ip_from 10.223.0.0/16;
-    real_ip_header CF-Connecting-IP;
 
-    # Map to get the most reliable client IP
+    # Use X-Forwarded-For to reconstruct client IP through trusted proxies
+    real_ip_header X-Forwarded-For;
+    real_ip_recursive on;
+
+    # Prefer Cloudflare-provided client IP headers when they exist,
+    # otherwise fall back to the resolved real IP from the proxy chain.
+    map $http_true_client_ip $tci_or_real {
+        ""      $realip_remote_addr;
+        default $http_true_client_ip;
+    }
     map $http_cf_connecting_ip $client_ip {
-        "" $remote_addr;
+        ""      $tci_or_real;
         default $http_cf_connecting_ip;
     }
 
-    # Debug logging format to see all IP variables
-    log_format debug_ips '$remote_addr - $realip_remote_addr - $http_cf_connecting_ip - $http_x_forwarded_for - $http_x_real_ip';
+    # Debug format to help validate IP forwarding behavior
+    log_format debug_ips 'remote_addr=$remote_addr realip_remote_addr=$realip_remote_addr client_ip=$client_ip cf_connecting_ip=$http_cf_connecting_ip x_forwarded_for="$http_x_forwarded_for" x_real_ip=$http_x_real_ip';
+
     server {
-        listen 80 default backlog=16384;
-        listen [::]:80 default backlog=16384;
+        listen 80 default_server backlog=16384;
+        listen [::]:80 default_server backlog=16384;
 
-        # Enable debug logging
+        # Enable debug logging to stdout
         access_log /dev/stdout debug_ips;
 
-        location /lib.min.js {
-            proxy_set_header X-Real-IP $client_ip;
-            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-            proxy_set_header X-Forwarded-Host $server_name;
+        # Common proxy headers applied to all locations
+        proxy_set_header X-Real-IP $client_ip;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Host $host;
+        proxy_set_header X-Forwarded-Proto $scheme;
+
+        # Mixpanel JS libraries
+        location = /lib.min.js {
             proxy_pass https://cdn.mxpnl.com/libs/mixpanel-2-latest.min.js;
         }
-
-        location /lib.js {
-            proxy_set_header X-Real-IP $client_ip;
-            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-            proxy_set_header X-Forwarded-Host $server_name;
+        location = /lib.js {
             proxy_pass https://cdn.mxpnl.com/libs/mixpanel-2-latest.js;
         }
 
-        location /decide {
+        # Decide endpoint
+        location = /decide {
             proxy_set_header Host decide.mixpanel.com;
-            proxy_set_header X-Real-IP $client_ip;
-            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-            proxy_set_header X-Forwarded-Host $server_name;
-            proxy_set_header X-Forwarded-Proto $scheme;
             proxy_pass https://decide.mixpanel.com/decide;
         }
 
+        # Catch-all forwards to Mixpanel's main API
         location / {
             proxy_set_header Host api.mixpanel.com;
-            proxy_set_header X-Real-IP $client_ip;
-            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-            proxy_set_header X-Forwarded-Host $server_name;
-            proxy_set_header X-Forwarded-Proto $scheme;
 
-            # Comprehensive debug headers
+            # Extra debug headers for troubleshooting IP forwarding/geolocation
             proxy_set_header X-Debug-RemoteAddr $remote_addr;
             proxy_set_header X-Debug-RealIP $realip_remote_addr;
+            proxy_set_header X-Debug-ClientIP $client_ip;
             proxy_set_header X-Debug-CFConnectingIP $http_cf_connecting_ip;
             proxy_set_header X-Debug-XForwardedFor $http_x_forwarded_for;
             proxy_set_header X-Debug-XRealIP $http_x_real_ip;
             proxy_set_header X-Debug-UserAgent $http_user_agent;
             proxy_set_header X-Debug-Referer $http_referer;
             proxy_set_header X-Debug-TrueClientIP $http_true_client_ip;
-            proxy_set_header X-Debug-XForwardedForOriginal $http_x_forwarded_for_original;
-            proxy_set_header X-Debug-AllHeaders "$http_user_agent $http_referer $http_cf_connecting_ip $http_x_forwarded_for $http_x_real_ip $http_true_client_ip";
 
             proxy_pass https://api.mixpanel.com/;
         }