proxy_wasm_request_headers_in_access
The `proxy_wasm_request_headers_in_access` directive specifies a WebAssembly filter to be executed when processing incoming request headers.
Description
The proxy_wasm_request_headers_in_access directive is a part of the WasmX module used in NGINX to enable the execution of WebAssembly (Wasm) code for additional processing during the request lifecycle. It allows users to specify which Wasm filter should be invoked during the access phase of processing incoming request headers. The directive plays a critical role in extending NGINX functionalities by enabling dynamic behavior such as header modification, logging, or authorization checks.
This directive's parameter is the name of the Wasm module that contains the filter to be executed. By using the proxy_wasm_request_headers_in_access, developers can create tailored processing logic that operates seamlessly within the NGINX request handling flow. This enhances NGINX's extensibility, particularly for use cases that require sophisticated request handling or integration with microservices.
Additionally, since this directive can be used in various contexts like http, server, or location, it provides flexibility in where developers can apply their custom Wasm filters within the NGINX configuration. Properly implementing the directive enables responsive and dynamic web applications capable of handling complex workflows efficiently.
Config Example
http {
server {
listen 80;
location / {
proxy_pass http://backend_service;
proxy_wasm_request_headers_in_access my_custom_filter;
}
}
}Ensure the specified Wasm filter is correctly compiled and available at runtime.
Check that the function in the Wasm module is correctly defined and matches the expected signature.
Be aware of performance implications when using Wasm filters extensively.