Using nginx as a reverse proxy

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Note: The following self-hosted proxy isn't provided by PostHog, so we can't take responsibility for it! If unsure, we recommend using our managed reverse proxy.

Note: If you are using the EU cloud then use eu instead of us in all domains (e.g. us.i.posthog.com -> eu.i.posthog.com)

You can use nginx as a reverse proxy. To do this, first create a Dockerfile to build a nginx container:

dockerfile
FROM nginx:alpine
COPY nginx.conf /etc/nginx/nginx.conf

Next, create the nginx.conf file with the reverse proxy configuration. The following checks the Referer header to ensure the request is coming from your domain (set as hogbook.com in this case), then proxies the request to PostHog Cloud US. Change us to eu to proxy to our EU Cloud.

nginx.conf
# The main context
events {
    worker_connections 1024;
}


http {
    server {
        listen 8080;  # Set the port to 8080


        server_name _;  # Accept requests for any domain


        # Specify DNS resolver for variables, this is Google Public DNS
        # You should adjust this to a DNS resolver of your choice
        resolver 8.8.8.8 8.8.4.4 [2001:4860:4860::]:8888 [2001:4860:4860::]:8844 valid=300s;
        resolver_timeout 5s;  # Timeout for DNS resolution


        # Check Referer header
        # Change hogbook to your domain as needed to ensure requests only come from your domain
        set $valid_referer 0;
        if ($http_referer ~* "^https?://(localhost|([a-zA-Z0-9-]+)\.hogbook\.com)") {
            set $valid_referer 1;
        }


        if ($valid_referer = 0) {
            return 403;  # Return forbidden if the Referer header is invalid
        }


        location ~ ^/static/(.*)$ {
            set $posthog_static "https://us-assets.i.posthog.com/static/";
            # use variable to force proper DNS re-resolution, also must manually pass along path
            proxy_pass $posthog_static$1$is_args$args;
            proxy_set_header Host "us-assets.i.posthog.com";
        }


        location ~ ^/(.*)$ {
            set $posthog_main "https://us.i.posthog.com/";
            # use variable to force proper DNS re-resolution, also must manually pass along path
            proxy_pass $posthog_main$1$is_args$args;
            proxy_set_header Host "us.i.posthog.com";
        }
    }
}

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