MEDIUM: config: report a warning when multiple servers have the same name

A config where multiple servers have the same name in the same backend is
prone to a number of issues : logs are not really exploitable, stats get
really tricky and even harder to change, etc...

In fact, it can be safe to have the same name between multiple servers only
when their respective IDs are known and used. So now we detect this situation
and emit a warning for the first conflict detected per server if any of the
servers uses an automatic ID.

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 864a9fb9babf1d9c371e55811c5983e808f3fe89..e11730e5abbaa80310bae6e61fa0a70e43077634 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -6937,6 +6937,30 @@ out_uri_auth_compat:
                        curproxy->srv = next;
                }
 
+               /* Check that no server name conflicts. This causes trouble in the stats.
+                * We only emit a warning for the first conflict affecting each server,
+                * in order to avoid combinatory explosion if all servers have the same
+                * name. We do that only for servers which do not have an explicit ID,
+                * because these IDs were made also for distinguishing them and we don't
+                * want to annoy people who correctly manage them.
+                */
+               for (newsrv = curproxy->srv; newsrv; newsrv = newsrv->next) {
+                       struct server *other_srv;
+
+                       if (newsrv->puid)
+                               continue;
+
+                       for (other_srv = curproxy->srv; other_srv && other_srv != newsrv; other_srv = other_srv->next) {
+                               if (!other_srv->puid && strcmp(other_srv->id, newsrv->id) == 0) {
+                                       Warning("parsing [%s:%d] : %s '%s', another server named '%s' was defined without an explicit ID at line %d, this is not recommended.\n",
+                                               newsrv->conf.file, newsrv->conf.line,
+                                               proxy_type_str(curproxy), curproxy->id,
+                                               newsrv->id, other_srv->conf.line);
+                                       break;
+                               }
+                       }
+               }
+
                /* assign automatic UIDs to servers which don't have one yet */
                next_id = 1;
                newsrv = curproxy->srv;