Random hacky snippets for use within Nginx, mostly for debugging purposes.

links.rst

Iterating through a list within Nginx:

https://github.com/nginx/nginx/blob/master/src/core/ngx_list.h#L57

nginx-snippets.c

/* Injecting a header within Nginx core code
 * ngx_http_request_t *r;   is predefined.
 */
ngx_table_elt_t               *h;
h = ngx_list_push(&r->headers_out.headers);
if (h == NULL) {
    return NGX_ERROR;
}
h->hash = 1;
ngx_str_set(&h->key, "Header")
ngx_str_set(&h->value, "Value")

/* Logging within the debug log
 * debug1 can be debug0 through debug8, depending on the number of arguments to pass
 * sprintf formatting can feature %V, for value, %i for integer, etc.
 * This example logging outputs the fake header as we defined above.
 */
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "**** %V: %V", &h->key, &h->value);