Description:
I am facing an issue in Nginx where certain response headers, such as Strict-Transport-Security, and X-Request-Time, are appearing twice in the response headers.
Issue Details:
- I have multiple location blocks handling API routes (/api/1.1/…).
- I use proxy_pass to forward requests to an upstream server (api2).
- I have used rewrite … break; inside some location blocks, expecting that once a request matches, it should not be evaluated further.
- Despite this, some requests appear to be processed by multiple location blocks, causing duplicate headers in the response.
Debugging Steps Taken:
- Checked Logs: Used log_format and added custom response headers to confirm that some requests are processed more than once.
- Enabled Debug Mode: error_log /var/log/nginx/error.log debug; rewrite_log on; revealed that certain requests might be internally redirected.
Questions:
- Why is Nginx evaluating multiple location blocks for the same request even after using rewrite … break;?
- How can I ensure that a request is handled by only one location block and does not proceed to another?
- Is there a way to completely prevent duplicate headers in the response when using proxy_pass?