BUG/MEDIUM: stats: mismatch between behaviour and doc about front/back

In version 1.3.4, we got the ability to split configuration parts between
frontends and backends. The stats was attached to the backend and a control
was made to ensure that it was used only in a listen or backend section, but
not in a frontend.

The documentation clearly says that the statement may only be used in the
backend.

But since that same version above, the defaults stats configuration is
only filled in the frontend part of the proxy and not in the backend's.
So a backend will not get stats which are enabled in a defaults section,
despite what the doc says. However, a frontend configured after a defaults
section will get stats and will not emit the warning!

There were many technical limitations in 1.3.4 making it impossible to
have the stats working both in the frontend and backend, but now this has
become a total mess.

It's common however to see people create a frontend with a perfectly
working stats configuration which only emits a warning stating that it
might not work, adding to the confusion. Most people workaround the tricky
behaviour by declaring a "listen" section with no server, which was the
recommended solution in 1.3 where it was even suggested to add a dispatch
address to avoid a warning.

So the right solution seems to do the following :

  - ensure that the defaults section's settings apply to the backends,
    as documented ;

  - let the frontends work in order not to break existing setups relying
    on the defaults section ;

  - officially allow stats to be declared in frontends and remove the
    warninng

This patch should probably not be backported since it's not certain that
1.4 is fully compatible with having stats in frontends and backends (which
was really made possible thanks to applets).

diff --git a/doc/configuration.txt b/doc/configuration.txt
index 3c34349ba8d43bc9b4c3b377d686fa2d8ec4e12b..3c245abada966222589cf66bb5164de42292a130 100644 (file)
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -5983,7 +5983,7 @@ srvtimeout <timeout> (deprecated)
 stats admin { if | unless } <cond>
   Enable statistics admin level if/unless a condition is matched
   May be used in sections :   defaults | frontend | listen | backend
-                                 no    |    no    |   yes  |   yes
+                                 no    |    yes   |   yes  |   yes
 
   This statement enables the statistics admin level if/unless a condition is
   matched.
@@ -6036,7 +6036,7 @@ stats admin { if | unless } <cond>
 stats auth <user>:<passwd>
   Enable statistics with authentication and grant access to an account
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments :
     <user>    is a user name to grant access to
 
@@ -6085,7 +6085,7 @@ stats auth <user>:<passwd>
 stats enable
   Enable statistics reporting with default settings
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments : none
 
   This statement enables statistics reporting with default settings defined
@@ -6123,7 +6123,7 @@ stats enable
 stats hide-version
   Enable statistics and hide HAProxy version reporting
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments : none
 
   By default, the stats page reports some useful status information along with
@@ -6182,7 +6182,7 @@ stats http-request { allow | deny | auth [realm <realm>] }
 stats realm <realm>
   Enable statistics and set authentication realm
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments :
     <realm>   is the name of the HTTP Basic Authentication realm reported to
               the browser. The browser uses it to display it in the pop-up
@@ -6222,7 +6222,7 @@ stats realm <realm>
 stats refresh <delay>
   Enable statistics with automatic refresh
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments :
     <delay>   is the suggested refresh delay, specified in seconds, which will
               be returned to the browser consulting the report page. While the
@@ -6264,7 +6264,7 @@ stats refresh <delay>
 stats scope { <name> | "." }
   Enable statistics and limit access scope
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments :
     <name>    is the name of a listen, frontend or backend section to be
               reported. The special name "." (a single dot) designates the
@@ -6305,7 +6305,7 @@ stats scope { <name> | "." }
 stats show-desc [ <desc> ]
   Enable reporting of a description on the statistics page.
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
 
     <desc>    is an optional description to be reported. If unspecified, the
               description from global section is automatically used instead.
@@ -6330,6 +6330,11 @@ stats show-desc [ <desc> ]
 
 
 stats show-legends
+  Enable reporting additional information on the statistics page
+  May be used in sections :   defaults | frontend | listen | backend
+                                 yes   |    yes   |   yes  |   yes
+  Arguments : none
+
   Enable reporting additional information on the statistics page :
     - cap: capabilities (proxy)
     - mode: one of tcp, http or health (proxy)
@@ -6347,7 +6352,7 @@ stats show-legends
 stats show-node [ <name> ]
   Enable reporting of a host name on the statistics page.
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments:
     <name>    is an optional name to be reported. If unspecified, the
               node name from global section is automatically used instead.
@@ -6375,7 +6380,7 @@ stats show-node [ <name> ]
 stats uri <prefix>
   Enable statistics and define the URI prefix to access them
   May be used in sections :   defaults | frontend | listen | backend
-                                 yes   |    no    |   yes  |   yes
+                                 yes   |    yes   |   yes  |   yes
   Arguments :
     <prefix>  is the prefix of any URI which will be redirected to stats. This
               prefix may contain a question mark ('?') to indicate part of a

diff --git a/src/cfgparse.c b/src/cfgparse.c
index c2c188695eee6c84c72959f08ba1c6a2df2abd65..19c5599572b2b43beeeb7a7e4d1e8d9cff59f41c 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1971,7 +1971,6 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
                        curproxy->timeout.tarpit = defproxy.timeout.tarpit;
                        curproxy->timeout.httpreq = defproxy.timeout.httpreq;
                        curproxy->timeout.httpka = defproxy.timeout.httpka;
-                       curproxy->uri_auth  = defproxy.uri_auth;
                        curproxy->mon_net = defproxy.mon_net;
                        curproxy->mon_mask = defproxy.mon_mask;
                        if (defproxy.monitor_uri)
@@ -2007,6 +2006,7 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
                }
 
                curproxy->mode = defproxy.mode;
+               curproxy->uri_auth = defproxy.uri_auth; /* for stats */
 
                /* copy default logsrvs to curproxy */
                list_for_each_entry(tmplogsrv, &defproxy.logsrvs, list) {
@@ -3284,9 +3284,6 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
                        LIST_ADDQ(&curproxy->sticking_rules, &rule->list);
        }
        else if (!strcmp(args[0], "stats")) {
-               if (warnifnotcap(curproxy, PR_CAP_BE, file, linenum, args[0], NULL))
-                       err_code |= ERR_WARN;
-
                if (curproxy != &defproxy && curproxy->uri_auth == defproxy.uri_auth)
                        curproxy->uri_auth = NULL; /* we must detach from the default config */