glusterd-hooks: added support for separate namespace for 'volume set' keys

The keys in the above mentioned namespace could be used by hook
scripts to peform tasks on 'special' keys as defined by the storage
admin. The choice of the key and its semantics of it are outside
the scope of glusterd. It is the responsibility of the storage admin
to keep the meaning of the key(s) consistent.

If a user gives a command like

 'gluster volume set <VOLNAME> user.for-this-key do-this"

scripts would get 'user.for-this-key=do-this' as argument.

Change-Id: I5509e17d99e4ddd8bf5df968dcd51ff9a80dc3ab
Signed-off-by: Amar Tumballi <amarts@redhat.com>
BUG: 825902
Reviewed-on: http://review.gluster.com/3443
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

2 files changed, 32 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-hooks.h b/xlators/mgmt/glusterd/src/glusterd-hooks.h
index 120fd5a47..e717395be 100644
--- a/xlators/mgmt/glusterd/src/glusterd-hooks.h
+++ b/xlators/mgmt/glusterd/src/glusterd-hooks.h
@@ -25,12 +25,16 @@
 #include "config.h"
 #endif
 
+#include <fnmatch.h>
+
 #define GLUSTERD_GET_HOOKS_DIR(path, version, priv) \
         snprintf (path, PATH_MAX, "%s/hooks/%d", priv->workdir,\
                   version);
 
 #define GLUSTERD_HOOK_VER       1
 
+#define GD_HOOKS_SPECIFIC_KEY   "user.*"
+
 typedef enum glusterd_commit_hook_type {
         GD_COMMIT_HOOK_NONE = 0,
         GD_COMMIT_HOOK_PRE,
@@ -55,6 +59,22 @@ typedef struct hooks_stub {
 } glusterd_hooks_stub_t;
 
 
+static inline gf_boolean_t
+is_key_glusterd_hooks_friendly (xlator_t *this, char *volname, char *key)
+{
+        gf_boolean_t is_friendly = _gf_false;
+
+        /* This is very specific to hooks friendly behavior */
+        if (fnmatch (GD_HOOKS_SPECIFIC_KEY, key, FNM_NOESCAPE) == 0) {
+                gf_log (this->name, GF_LOG_DEBUG,
+                        "user configured key (%s) sent on volume %s",
+                        key, volname);
+                is_friendly = _gf_true;
+        }
+
+        return is_friendly;
+}
+
 int
 glusterd_hooks_create_hooks_directory (char *basedir);
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index f727a76eb..9b635f021 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -415,6 +415,12 @@ glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)
                         ret = 0;
                         goto out;
                 }
+
+                if (is_key_glusterd_hooks_friendly (this, volname, key)) {
+                        ret = 0;
+                        goto out;
+                }
+
                 exists = glusterd_check_option_exists (key, &key_fixed);
                 if (exists == -1) {
                         ret = -1;
@@ -1106,6 +1112,12 @@ glusterd_op_set_volume (dict_t *dict)
                                                  &volinfo->memory_accounting);
                         goto out;
                 }
+
+                if (is_key_glusterd_hooks_friendly (this, volname, key)) {
+                        ret = 0;
+                        goto out;
+                }
+
                 ret = glusterd_check_option_exists (key, &key_fixed);
                 GF_ASSERT (ret);
                 if (ret == -1) {