glusterd, cli: implement gluster system uuid reset command

A commonly faced problem among glusterfs users is: after a fresh
installation of glusterfs in a virtual machine, the VM image is
cloned to make multiple instances of the server. This breaks
glusterd because right after glusterfs installation on the first
boot glusterd would have created the node UUID and this gets
inherited into the clone. The result is wierd behavior at the time
of peer probe where glusterd does not (yet) deal with UUID
collisions in a user friendly way.

To handle it gluster peer reset command is implemented which upon
execution changes the uuid of local glusterd.

Change-Id: If207dd2ad93ab94ef1a3253f409c21c442975f87
BUG: 811493
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/3637
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/cli/src/cli-cmd-system.c b/cli/src/cli-cmd-system.c
index 255eb605e64..b969c227b31 100644
--- a/cli/src/cli-cmd-system.c
+++ b/cli/src/cli-cmd-system.c
@@ -278,6 +278,67 @@ cli_cmd_umount_cbk (struct cli_state *state, struct cli_cmd_word *word,
         return ret;
 }
 
+int
+cli_cmd_uuid_reset_cbk (struct cli_state *state, struct cli_cmd_word *word,
+                        const char **words, int wordcount)
+{
+        int                     ret = -1;
+        rpc_clnt_procedure_t    *proc = NULL;
+        call_frame_t            *frame = NULL;
+        int                     sent = 0;
+        int                     parse_error = 0;
+        gf_answer_t             answer = GF_ANSWER_NO;
+        char                    *question = NULL;
+        cli_local_t             *local = NULL;
+        dict_t                  *dict  = NULL;
+        xlator_t                *this  = NULL;
+
+        question = "Resetting uuid changes the uuid of local glusterd. "
+                   "Do you want to continue?";
+
+        if (wordcount != 3) {
+                cli_usage_out (word->pattern);
+                parse_error = 1;
+                goto out;
+        }
+
+        proc = &cli_rpc_prog->proctable[GLUSTER_CLI_UUID_RESET];
+
+        this = THIS;
+        frame = create_frame (this, this->ctx->pool);
+        if (!frame)
+                goto out;
+
+        dict = dict_new ();
+        if (!dict) {
+                ret = -1;
+                goto out;
+        }
+        CLI_LOCAL_INIT (local, words, frame, dict);
+        answer = cli_cmd_get_confirmation (state, question);
+
+        if (GF_ANSWER_NO == answer) {
+                ret = 0;
+                goto out;
+        }
+
+        //send NULL as argument since no dictionary is sent to glusterd
+        if (proc->fn) {
+                ret = proc->fn (frame, this, dict);
+        }
+
+out:
+        if (ret) {
+                cli_cmd_sent_status_get (&sent);
+                if ((sent == 0) && (parse_error == 0))
+                        cli_out ("uuid reset failed");
+        }
+
+        CLI_STACK_DESTROY (frame);
+
+        return ret;
+}
+
 struct cli_cmd cli_system_cmds[] = {
         { "system:: getspec <VOLID>",
           cli_cmd_getspec_cbk,
@@ -303,6 +364,10 @@ struct cli_cmd cli_system_cmds[] = {
           cli_cmd_umount_cbk,
           "request an umount"},
 
+        { "system:: uuid reset",
+          cli_cmd_uuid_reset_cbk,
+          "reset the uuid of glusterd"},
+
         { "system:: help",
            cli_cmd_system_help_cbk,
            "display help for system commands"},