HTTP: added route logging.

-  Configuration: added "/config/settings/http/log_route".

   Type: bool
   Default: false

   This adds configurability to the error log.  It allows enabling and
   disabling logs related to how the router performs selection of the
   routes.

-  HTTP: logging request line.

   Log level: [notice]

   The request line is essential to understand which logs correspond to
   which request when reading the logs.

-  HTTP: logging route that's been discarded.

   Log level: [info]

-  HTTP: logging route whose action is selected.

   Log level: [notice]

-  HTTP: logging when "fallback" action is taken.

   Log level: [notice]

Closes: <https://github.com/nginx/unit/issues/758>
Link: <https://github.com/nginx/unit/pull/824>
Link: <https://github.com/nginx/unit/pull/839>
Suggested-by: Timo Stark <t.stark@nginx.com>
Suggested-by: Mark L Wood-Patrick <mwoodpatrick@gmail.com>
Suggested-by: Liam Crilly <liam@nginx.com>
Tested-by: Liam Crilly <liam@nginx.com>
Acked-by: Artem Konev <a.konev@f5.com>
Cc: Andrew Clayton <a.clayton@nginx.com>
Cc: Andrei Zeliankou <zelenkov@nginx.com>
Reviewed-by: Zhidao Hong <z.hong@f5.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/nxt_http_static.c b/src/nxt_http_static.c
index 68174b9d..5e44aab4 100644
--- a/src/nxt_http_static.c
+++ b/src/nxt_http_static.c
@@ -196,6 +196,9 @@ nxt_http_static(nxt_task_t *task, nxt_http_request_t *r,
 
         if (!nxt_str_eq(r->method, "HEAD", 4)) {
             if (action->fallback != NULL) {
+                if (nxt_slow_path(r->log_route)) {
+                    nxt_log(task, NXT_LOG_NOTICE, "\"fallback\" taken");
+                }
                 return action->fallback;
             }
 
@@ -690,6 +693,9 @@ nxt_http_static_next(nxt_task_t *task, nxt_http_request_t *r,
     }
 
     if (action->fallback != NULL) {
+        if (nxt_slow_path(r->log_route)) {
+            nxt_log(task, NXT_LOG_NOTICE, "\"fallback\" taken");
+        }
         nxt_http_request_action(task, r, action->fallback);
         return;
     }