Kimserey's blog

Inspect proxied requests from Nginx to Kestrel with Mitmproxy In previous blog posts, we saw how to proxy requests to an ASP NET Core application using Nginx . We saw that request headers also can be proxied with proxy_set_header In order to ease development, we need to be able to debug the values to verify that they are what we expect. Today we will see two methods to inspect the proxied requests. This post will be composed by two parts: Nginx location routing Nginx variable debugging Nginx proxied request debug with Mitmproxy 1 Nginx location routing Considering the following configuration of our server: server { listen 80; location / { proxy_pass http://localhost:5000; } location /api/ { proxy_pass http://localhost:5001/; } } If we want to check whether our location routes are properly configured, we can short circuit the proxy_pass with return and use curl to check whether the location is properly selected. server { listen ...

Nginx 502 bad gateway after SSL setup When proxying a request to an underlying server, it is necessary to validate its SSL certificate. For example, if we have a process running on https://localhost:5001 , we can configure Nginx to validate the certificate used by localhost:5001 . But if we miss one step, we face the common error 502 Bad Gateway returned by Nginx. Today we will see two scenarios where we can face the error and how to fix them: Setup SSL verification Scenario 1: self-signed certificate Scenario 2: upstream server 1. Setup SSL verification We can tell Nginx to verify the underlying SSL by adding the following directives, either on server or location level: server { // ... more config proxy_ssl_trusted_certificate /etc/ssl/certs/ca-certificates.crt; proxy_ssl_verify on; proxy_ssl_session_reuse on; location / { proxy_pass https://localhost:5001/; } } proxy_ssl_trusted_certificate indicates to Nginx the location of the trusted CA certificates...