final

Author: Revolyssup

config

@@ -1,7 +1,6 @@
 ngx_module_type=HTTP
 ngx_module_name=ngx_http_apisix_module
 ngx_module_srcs="$ngx_addon_dir/src/ngx_http_apisix_module.c"
-ngx_module_srcs="$ngx_addon_dir/src/ngx_http_apisix_log_handler.c"
 ngx_module_deps=$ngx_addon_dir/src/ngx_http_apisix_module.h
 ngx_module_incs="$ngx_addon_dir/src"
 

src/ngx_http_apisix_log_handler.c

@@ -1,9 +1,9 @@
 
+#include <ngx_config.h>
 #include <ngx_core.h>
 #include <ngx_http.h>
-#include <ngx_http_realip_module.c>
+#include <ngx_http_realip_module.h>
 #include "ngx_http_apisix_module.h"
-#include "ngx_http_apisix_log_handler.c"
 
 #define NGX_HTTP_APISIX_SSL_ENC     1
 #define NGX_HTTP_APISIX_SSL_SIGN    2
@@ -51,6 +51,7 @@ static ngx_command_t ngx_http_apisix_cmds[] = {
     },
     ngx_null_command
 };
+
 static ngx_http_module_t ngx_http_apisix_module_ctx = {
     NULL,                                    /* preconfiguration */
     ngx_http_apisix_init,                                    /* postconfiguration */
@@ -838,3 +839,132 @@ ngx_http_apisix_is_ntls_enabled(ngx_http_conf_ctx_t *conf_ctx)
     acf = ngx_http_get_module_main_conf(conf_ctx, ngx_http_apisix_module);
     return acf->enable_ntls;
 }
+
+/*******************Log handler***************** */
+/*
+ * This function contains the logic to append the Request ID to
+ * the error log line when being called.
+ * Get the location configuration from helper function. Find indexed variable with the loc_conf->request_id_var_index. and add that to buffer.
+ */
+static u_char*
+ngx_http_apisix_error_log_handler(ngx_http_request_t *r, u_char *buf, size_t len)
+{
+		ngx_http_variable_value_t *request_id_var;
+		ngx_http_apisix_loc_conf_t *loc_conf;
+
+		loc_conf = ngx_http_get_module_loc_conf(r, ngx_http_apisix_module);
+		if (loc_conf->request_id_var_index == NGX_CONF_UNSET) {
+				return buf;
+		}
+
+		request_id_var = ngx_http_get_indexed_variable(r, loc_conf->request_id_var_index);
+		if (request_id_var == NULL || request_id_var->not_found) {
+				return buf;
+		}
+		buf = ngx_snprintf(buf, len, ", request_id: \"%v\"", request_id_var);
+		return buf;
+}
+
+
+/*
+ * This function replaces the original HTTP error
+ * log handler (r->log_handler). It executes the original logic
+ * and then our error log handler: ngx_http_apisix_error_log_handler
+ * This function returns the final message.
+ */
+static u_char*
+ngx_http_apisix_combined_error_log_handler(ngx_http_request_t *r, ngx_http_request_t *sr, u_char *buf, size_t len)
+{
+		u_char *p;
+		ngx_http_apisix_ctx_t *ctx;
+
+		ctx = ngx_http_apisix_get_module_ctx(r);
+		if (ctx == NULL || ctx->orig_log_handler == NULL) {
+				return buf;
+		}
+
+		//Get the original log message
+		p = ctx->orig_log_handler(r, sr, buf, len);
+		//p - buf calculates the number of bytes written by the original log handler into the buffer.
+		//len -= (p - buf) reduces the remaining buffer length by the amount already used.
+		len -= p-buf;
+
+		//Apisix log handler
+		buf = ngx_http_apisix_error_log_handler(r, buf, len);
+		return buf;
+}
+
+
+//It replaces the r->log_handler which is the log handler of the request with the combined log handler.
+// Creates the apisix context we need from the request to act on it.
+static ngx_int_t
+ngx_http_apisix_replace_error_log_handler(ngx_http_request_t *r)
+{
+		ngx_http_apisix_ctx_t *ctx;
+
+		ctx = ngx_http_apisix_get_module_ctx(r);
+		if (ctx == NULL) {
+				return NGX_OK;
+		}
+
+		if (r->log_handler == NULL){
+				return NGX_DECLINED;
+		}
+
+    /*
+     * Store the original log handler in ctx->orig_log_handler, replace
+     * it with the combined log handler, which will execute the original
+     * handler's logic in addition to our own.
+     */
+		ctx->orig_log_handler = r->log_handler;
+		r->log_handler = ngx_http_apisix_combined_error_log_handler;
+
+		return NGX_DECLINED;
+}
+
+//This function is part of postconfiguration passed to module context and will override the post_read_phase with custom log handler.
+// It extracts the pointer to log handler from the post read phase handlers and then override that with new function address.
+char *
+ngx_http_apisix_error_log_init(ngx_conf_t *cf)
+{
+		ngx_http_handler_pt *h;
+		ngx_http_core_main_conf_t *cmcf;
+
+		cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
+		h = ngx_array_push(&cmcf->phases[NGX_HTTP_POST_READ_PHASE].handlers);
+		if (h == NULL) {
+        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                           "failed setting error log handler");
+        return NGX_CONF_ERROR;
+    }
+
+		*h = ngx_http_apisix_replace_error_log_handler;
+
+		return NGX_CONF_OK;
+}
+
+// This function does the translation of the configuration file to the internal representation.
+// So this will just set the value in loc_conf that it gets by reference.
+char * 
+ngx_http_apisix_error_log_request_id(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
+{
+    ngx_str_t *value;
+		ngx_http_apisix_loc_conf_t *loc_conf = conf;
+
+		value = cf->args->elts;
+		if (value[1].data[0] != '$') {
+				ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &value[1]);
+				return NGX_CONF_ERROR;
+		}
+
+		value[1].len--;
+		value[1].data++;
+
+		loc_conf->request_id_var_index = ngx_http_get_variable_index(cf, &value[1]);
+		if (loc_conf->request_id_var_index == NGX_ERROR) {
+				return NGX_CONF_ERROR;
+		}
+
+		return NGX_CONF_OK;
+}
+