glusterd: Added init scripts like interface for gluster commands

Directories to hold the scripts mentioned above would be created for each
gluster command under glusterd's 'working dir' as follows:
(eg.)
<glusterd-working-dir>/hooks/version/create/pre

<glusterd-working-dir>/hooks/version/create/post

where, version corresponds to the version of hook scripts.

The scripts beginning with 'S' under the above directories would be run before
(pre) and after (post) the volume created. The scripts would receive a command
line argument as below:
--volname=<volname>

This can be optionally used  by the script.

Change-Id: Ia81b4ff9dd4477d99dd59b39c805aa645521edb0
BUG: 806996
Signed-off-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-on: http://review.gluster.com/3010
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Csaba Henk <csaba@redhat.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 211 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 56c1d9875..4cfbf5e4c 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -51,6 +51,39 @@
 #include <inttypes.h>
 #include <dirent.h>
 
+extern int mkdir_if_missing (char *dir);
+
+#define EMPTY ""
+char glusterd_hook_dirnames[GD_OP_MAX][256] =
+{
+        [GD_OP_NONE]                    = EMPTY,
+        [GD_OP_CREATE_VOLUME]           = "create",
+        [GD_OP_START_BRICK]             = EMPTY,
+        [GD_OP_STOP_BRICK]              = EMPTY,
+        [GD_OP_DELETE_VOLUME]           = "delete",
+        [GD_OP_START_VOLUME]            = "start",
+        [GD_OP_STOP_VOLUME]             = "stop",
+        [GD_OP_DEFRAG_VOLUME]           = EMPTY,
+        [GD_OP_ADD_BRICK]               = "add-brick",
+        [GD_OP_REMOVE_BRICK]            = "remove-brick",
+        [GD_OP_REPLACE_BRICK]           = EMPTY,
+        [GD_OP_SET_VOLUME]              = EMPTY,
+        [GD_OP_RESET_VOLUME]            = EMPTY,
+        [GD_OP_SYNC_VOLUME]             = EMPTY,
+        [GD_OP_LOG_ROTATE]              = EMPTY,
+        [GD_OP_GSYNC_SET]               = EMPTY,
+        [GD_OP_PROFILE_VOLUME]          = EMPTY,
+        [GD_OP_QUOTA]                   = EMPTY,
+        [GD_OP_STATUS_VOLUME]           = EMPTY,
+        [GD_OP_REBALANCE]               = EMPTY,
+        [GD_OP_HEAL_VOLUME]             = EMPTY,
+        [GD_OP_STATEDUMP_VOLUME]        = EMPTY,
+        [GD_OP_LIST_VOLUME]             = EMPTY,
+        [GD_OP_CLEARLOCKS_VOLUME]       = EMPTY,
+        [GD_OP_DEFRAG_BRICK_VOLUME]     = EMPTY,
+};
+#undef EMPTY
+
 static int32_t
 glusterd_store_mkdir (char *path)
 {
@@ -2464,3 +2497,181 @@ out:
         gf_log ("", GF_LOG_DEBUG, "Returning %d", ret);
         return ret;
 }
+
+static inline gf_boolean_t
+glusterd_is_hook_enabled (char *script)
+{
+        return (script[0] == 'S');
+}
+
+int
+glusterd_store_create_hooks_directory (char *basedir)
+{
+        int  ret                                        = -1;
+        int  op                                         = GD_OP_NONE;
+        int  type                                       = GD_COMMIT_HOOK_NONE;
+        char version_dir[PATH_MAX]                      = {0, };
+        char path[PATH_MAX]                             = {0, };
+        char *cmd_subdir                                = NULL;
+        char type_subdir[GD_COMMIT_HOOK_MAX][256]       = {{0, },
+                                                           "pre",
+                                                           "post"};
+        glusterd_conf_t *priv                           = NULL;
+
+        priv = THIS->private;
+
+        snprintf (path, sizeof (path), "%s/hooks", basedir);
+        ret = mkdir_if_missing (path);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_CRITICAL, "Unable to create %s due"
+                         "to %s", path, strerror (errno));
+                goto out;
+        }
+
+        GLUSTERD_GET_HOOKS_DIR (version_dir, GLUSTERD_HOOK_VER, priv);
+        ret = mkdir_if_missing (version_dir);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_CRITICAL, "Unable to create %s due "
+                        "to %s", version_dir, strerror (errno));
+                goto out;
+        }
+
+        for (op = GD_OP_NONE+1; op < GD_OP_MAX; op++) {
+                cmd_subdir = glusterd_store_get_hooks_cmd_subdir (op);
+                if (strlen (cmd_subdir) == 0)
+                        continue;
+
+                snprintf (path, sizeof (path), "%s/%s", version_dir,
+                          cmd_subdir);
+                ret = mkdir_if_missing (path);
+                if (ret) {
+                        gf_log (THIS->name, GF_LOG_CRITICAL,
+                                "Unable to create %s due to %s",
+                                path, strerror (errno));
+                        goto out;
+                }
+
+                for (type = GD_COMMIT_HOOK_PRE; type < GD_COMMIT_HOOK_MAX;
+                     type++) {
+                        snprintf (path, sizeof (path), "%s/%s/%s",
+                                  version_dir, cmd_subdir, type_subdir[type]);
+                        ret = mkdir_if_missing (path);
+                        if (ret) {
+                                gf_log (THIS->name, GF_LOG_CRITICAL,
+                                        "Unable to create %s due to %s",
+                                        path, strerror (errno));
+                                goto out;
+                        }
+                }
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
+
+char*
+glusterd_store_get_hooks_cmd_subdir (glusterd_op_t op)
+{
+        GF_ASSERT ((op > GD_OP_NONE) && (op < GD_OP_MAX));
+
+        return glusterd_hook_dirnames[op];
+}
+
+int
+glusterd_store_run_hooks (char *hooks_path, dict_t *op_ctx)
+{
+        xlator_t        *this                   = NULL;
+        glusterd_conf_t *priv                   = NULL;
+        runner_t        runner                  = {0, };
+        struct dirent   *entry                  = NULL;
+        DIR             *hookdir                = NULL;
+        char            *volname                = NULL;
+        char            **lines                 = NULL;
+        int             N                       = 8; /*arbitrary*/
+        int             lineno                  = 0;
+        int             line_count              = 0;
+        int             ret                     = -1;
+
+        this = THIS;
+        priv = this->private;
+
+        ret = dict_get_str (op_ctx, "volname", &volname);
+        if (ret) {
+                gf_log (this->name, GF_LOG_CRITICAL, "Failed to get volname "
+                        "from operation context");
+                goto out;
+        }
+
+        hookdir = opendir (hooks_path);
+        if (!hookdir) {
+                ret = -1;
+                gf_log (this->name, GF_LOG_ERROR, "Failed to open dir %s, due "
+                        "to %s", hooks_path, strerror (errno));
+                goto out;
+        }
+
+        lines = GF_CALLOC (1, N * sizeof (*lines), gf_gld_mt_charptr);
+        if (!lines) {
+                ret = -1;
+                goto out;
+        }
+
+        ret = -1;
+        line_count = 0;
+        glusterd_for_each_entry (entry, hookdir);
+        while (entry) {
+                if (line_count == N-1) {
+                        N *= 2;
+                        lines = GF_REALLOC (lines, N * sizeof (char *));
+                        if (!lines)
+                                goto out;
+                }
+
+                if (glusterd_is_hook_enabled (entry->d_name)) {
+                        lines[line_count] = gf_strdup (entry->d_name);
+                        line_count++;
+                }
+
+                glusterd_for_each_entry (entry, hookdir);
+        }
+
+        lines[line_count] = NULL;
+        lines = GF_REALLOC (lines, (line_count + 1) * sizeof (char *));
+        if (!lines)
+                goto out;
+
+        qsort (lines, line_count, sizeof (*lines), glusterd_compare_lines);
+
+        for (lineno = 0; lineno < line_count; lineno++) {
+
+                runinit (&runner);
+                runner_argprintf (&runner, "%s/%s", hooks_path, lines[lineno]);
+                /*Add future command line arguments to hook scripts below*/
+                runner_argprintf (&runner, "--volname=%s", volname);
+                ret = runner_run_reuse (&runner);
+                if (ret) {
+                        runner_log (&runner, this->name, GF_LOG_ERROR,
+                                    "Failed to execute script");
+                } else {
+                        runner_log (&runner, this->name, GF_LOG_INFO,
+                                    "Ran script");
+                }
+                runner_end (&runner);
+        }
+
+        ret = 0;
+out:
+        if (lines) {
+                for (lineno = 0; lineno < line_count+1; lineno++)
+                        if (lines[lineno])
+                                GF_FREE (lines[lineno]);
+
+                GF_FREE (lines);
+        }
+
+        if (hookdir)
+                closedir (hookdir);
+
+        return ret;
+}