Fix proxy_set_header for websocket and custom override locations

[mesudip]

No description provided.

[gemini-code-assist]

Code Review

This pull request introduces a ProxyHeaderProcessor to manage the reinsertion of default proxy headers when custom headers are injected or for websocket locations. It also updates the Jinja2 template to conditionally render these headers and adds comprehensive unit tests. The review feedback highlights a fragile type check in ProxyHeaderProcessor where checking for list instead of str can break other iterable types. Additionally, it suggests simplifying both the Python logic and the Jinja2 template by treating all websocket locations as requiring header reinsertion, which would eliminate redundant hardcoded blocks in the template.

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[gemini-code-assist]

Using isinstance(injected, list) to distinguish between a single string and an iterable of strings is fragile. Since str is also an Iterable, any other iterable type (such as set, tuple, or a custom sequence) will fail the list check and be incorrectly wrapped as a single-element list containing the iterable itself. This causes str(directive) to serialize the entire collection (e.g., "{'proxy_set_header ...'}"), which fails the regex match.

Instead, check if injected is a string to decide whether to wrap it.

Suggested change

	directives = injected if isinstance(injected, list) else [injected]
	directives = [injected] if isinstance(injected, str) else injected

[gemini-code-assist]

We can significantly simplify both the Python logic and the Jinja2 template by making needs_reinsertion True for all websocket locations (regardless of whether location.http is True or False).

Since any websocket location block must define at least Upgrade and Connection headers, Nginx's inheritance rules dictate that it will not inherit any global proxy_set_header directives. Therefore, all websocket locations always need the full set of default headers re-inserted.

If we change this condition to:

needs_reinsertion = bool(overridden_headers) or location.websocket

Then location.reinsert_global_config will be True for all websocket locations, and location.reinserted_proxy_set_headers will contain the complete list of headers.

This allows us to completely remove the redundant, hardcoded header blocks in vhosts_template/default.conf.jinja2 (lines 57-75), leaving only the clean loop over location.reinserted_proxy_set_headers.

Suggested change

	needs_reinsertion = bool(overridden_headers) or (location.websocket and not location.http)
	needs_reinsertion = bool(overridden_headers) or location.websocket

[gemini-code-assist]

If we simplify the Python logic in ProxyHeaderProcessor to set needs_reinsertion = True for all websocket locations (by changing needs_reinsertion = bool(overridden_headers) or location.websocket), we can completely eliminate the redundant, hardcoded header blocks here.

This leaves only the clean loop over location.reinserted_proxy_set_headers, greatly improving template maintainability.

            proxy_redirect $scheme://$http_host{{ location.container.path if location.container.path else '/' }} $scheme://$http_host{{location.name}};{% endif %} {% if location.reinsert_global_config %}{% for header_name, header_value in location.reinserted_proxy_set_headers %}
            proxy_set_header {{ header_name }} {{ header_value }};{% endfor %}{% endif %}{% if location.websocket and not location.http %}

[codecov]

Codecov Report

❌ Patch coverage is 95.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.61%. Comparing base (c8c60b0) to head (aff3d9e).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...nx_proxy/post_processors/proxy_header_processor.py	94.28%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #53      +/-   ##
==========================================
+ Coverage   70.31%   70.61%   +0.29%     
==========================================
  Files          31       32       +1     
  Lines        3261     3301      +40     
  Branches      542      550       +8     
==========================================
+ Hits         2293     2331      +38     
- Misses        801      802       +1     
- Partials      167      168       +1     

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