MINOR: compression: Warn for 'compression offload' in defaults sections

This directive is documented as being ignored if set in a defaults
section. But it is only mentionned in a small note in the configuration
manual. Thus, now, a warning is emitted. To do so, the errors handling in
parse_compression_options() function was slightly changed.

In addition, this directive is now documented apart from the other
compression directives. This way, it is clearly visible that it must not be
used in a defaults section.

diff --git a/doc/configuration.txt b/doc/configuration.txt
index 42efa329ee0a07fb4a3d0dfb7c4e8594a05dfe73..6f61e266075fb401b2c1da25e15dd2cebfc7d9e5 100644 (file)
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -4424,14 +4424,12 @@ clitcpka-intvl <timeout>
 
 compression algo <algorithm> ...
 compression type <mime type> ...
-compression offload
   Enable HTTP compression.
   May be used in sections :   defaults | frontend | listen | backend
                                  yes   |    yes   |   yes  |   yes
   Arguments :
     algo     is followed by the list of supported compression algorithms.
     type     is followed by the list of MIME types that will be compressed.
-    offload  makes HAProxy work as a compression offloader only (see notes).
 
   The currently supported algorithms are :
     identity     this is mostly for debugging, and it was useful for developing
@@ -4465,19 +4463,6 @@ compression offload
   there is Accept-Encoding header in request, HAProxy will compress the
   matching response.
 
-  The "offload" setting makes HAProxy remove the Accept-Encoding header to
-  prevent backend servers from compressing responses. It is strongly
-  recommended not to do this because this means that all the compression work
-  will be done on the single point where HAProxy is located. However in some
-  deployment scenarios, HAProxy may be installed in front of a buggy gateway
-  with broken HTTP compression implementation which can't be turned off.
-  In that case HAProxy can be used to prevent that gateway from emitting
-  invalid payloads. In this case, simply removing the header in the
-  configuration does not work because it applies before the header is parsed,
-  so that prevents HAProxy from compressing. The "offload" setting should
-  then be used for such scenarios. Note: for now, the "offload" setting is
-  ignored when set in a defaults section.
-
   Compression is disabled when:
     * the request does not advertise a supported compression algorithm in the
       "Accept-Encoding" header
@@ -4501,6 +4486,29 @@ compression offload
         compression algo gzip
         compression type text/html text/plain
 
+  See also : "compression offload"
+
+compression offload
+  Makes HAProxy work as a compression offloader only.
+  May be used in sections :   defaults | frontend | listen | backend
+                                 no    |    yes   |   yes  |   yes
+
+  The "offload" setting makes HAProxy remove the Accept-Encoding header to
+  prevent backend servers from compressing responses. It is strongly
+  recommended not to do this because this means that all the compression work
+  will be done on the single point where HAProxy is located. However in some
+  deployment scenarios, HAProxy may be installed in front of a buggy gateway
+  with broken HTTP compression implementation which can't be turned off.
+  In that case HAProxy can be used to prevent that gateway from emitting
+  invalid payloads. In this case, simply removing the header in the
+  configuration does not work because it applies before the header is parsed,
+  so that prevents HAProxy from compressing. The "offload" setting should
+  then be used for such scenarios.
+
+  If this setting is used in a defaults section, a warning is emitted and the
+  option is ignored.
+
+  See also : "compression type", "compression algo"
 
 cookie <name> [ rewrite | insert | prefix ] [ indirect ] [ nocache ]
               [ postonly ] [ preserve ] [ httponly ] [ secure ]

diff --git a/src/flt_http_comp.c b/src/flt_http_comp.c
index 9d8c3fa6402ea54a60c6ed6f50926af4158f622e..f2b210a6770d5fe8034cc8d6f5c3958e8d9d0e56 100644 (file)
--- a/src/flt_http_comp.c
+++ b/src/flt_http_comp.c
@@ -631,6 +631,7 @@ parse_compression_options(char **args, int section, struct proxy *proxy,
                          char **err)
 {
        struct comp    *comp;
+       int ret = 0;
 
        if (proxy->comp == NULL) {
                comp = calloc(1, sizeof(*comp));
@@ -644,58 +645,71 @@ parse_compression_options(char **args, int section, struct proxy *proxy,
                int              cur_arg = 2;
 
                if (!*args[cur_arg]) {
-                       memprintf(err, "parsing [%s:%d] : '%s' expects <algorithm>\n",
+                       memprintf(err, "parsing [%s:%d] : '%s' expects <algorithm>.",
                                  file, line, args[0]);
-                       return -1;
+                       ret = -1;
+                       goto end;
                }
                while (*(args[cur_arg])) {
                        int retval = comp_append_algo(comp, args[cur_arg]);
                        if (retval) {
                                if (retval < 0)
-                                       memprintf(err, "'%s' : '%s' is not a supported algorithm.\n",
+                                       memprintf(err, "'%s' : '%s' is not a supported algorithm.",
                                                  args[0], args[cur_arg]);
                                else
-                                       memprintf(err, "'%s' : out of memory while parsing algo '%s'.\n",
+                                       memprintf(err, "'%s' : out of memory while parsing algo '%s'.",
                                                  args[0], args[cur_arg]);
-                               return -1;
+                               ret = -1;
+                               goto end;
                        }
 
                        if (proxy->comp->algos->init(&ctx, 9) == 0)
                                proxy->comp->algos->end(&ctx);
                        else {
-                               memprintf(err, "'%s' : Can't init '%s' algorithm.\n",
+                               memprintf(err, "'%s' : Can't init '%s' algorithm.",
                                          args[0], args[cur_arg]);
-                               return -1;
+                               ret = -1;
+                               goto end;
                        }
                        cur_arg++;
                        continue;
                }
        }
-       else if (strcmp(args[1], "offload") == 0)
+       else if (strcmp(args[1], "offload") == 0) {
+               if (proxy->cap & PR_CAP_DEF) {
+                       memprintf(err, "'%s' : '%s' ignored in 'defaults' section.",
+                                 args[0], args[1]);
+                       ret = 1;
+               }
                comp->offload = 1;
+       }
        else if (strcmp(args[1], "type") == 0) {
                int cur_arg = 2;
 
                if (!*args[cur_arg]) {
-                       memprintf(err, "'%s' expects <type>\n", args[0]);
-                       return -1;
+                       memprintf(err, "'%s' expects <type>.", args[0]);
+                       ret = -1;
+                       goto end;
                }
                while (*(args[cur_arg])) {
                        if (comp_append_type(comp, args[cur_arg])) {
                                memprintf(err, "'%s': out of memory.", args[0]);
-                               return -1;
+                               ret = -1;
+                               goto end;
                        }
                        cur_arg++;
                        continue;
                }
        }
        else {
-               memprintf(err, "'%s' expects 'algo', 'type' or 'offload'\n",
+               memprintf(err, "'%s' expects 'algo', 'type' or 'offload'",
                          args[0]);
-               return -1;
+               ret = -1;
+               goto end;
        }
 
-       return 0;
+  end:
+       return ret;
 }
 
 static int