glusterd / cli: mount-broker service

Mountbroker is configured in glusterd volfile through a DSL
which is restriced enough to be able to appear in the role
of the value of a volfile knob.

Basically the DSL describes set-theorical requirements
against the option set which is sent by the cli (in the
hope of getting a mount with these options).

If the requirements meet and the volume id and the uid
who is to "own" the mount can be unambigously deduced from
the given request, glusterd does the mount with the given
parameters.

The use case of geo-replication is sugared by means of volume
options which then generate a complete mount-broker option set.

Demo:

- add the following option to your glusterd volfile:

    option mountbroker-root /tmp/mbr
    option mountbroker.fool EQL(volfile-id=pop*|user-map-root=*|volfile-server=localhost)&MEET(user-map-root=john|user-map-root=jane)

- before starting glusterd, create /tmp/mbr owned by root with mode 0755

- with cli, do

   $ gluster system:: mount fool volfile-id=pop33 user-map-root=jane volfile-server=localhost

- on succesful completion (volume pop33 exists and is started, jane is a valid username),
  the mount path will be echoed to you

- you can get rid of the mount by

   $ gluster system:: umount <mount-path>

Change-Id: I629cf64add0a45500d05becc3316f67cdb5b42ff
BUG: 3482
Reviewed-on: http://review.gluster.com/128
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 118 insertions, 0 deletions

diff --git a/cli/src/cli-cmd-system.c b/cli/src/cli-cmd-system.c
index 061cf4e83..25938b897 100644
--- a/cli/src/cli-cmd-system.c
+++ b/cli/src/cli-cmd-system.c
@@ -178,6 +178,116 @@ out:
         return ret;
 }
 
+static dict_t *
+make_seq_dict (int argc, char **argv)
+{
+        char index[] = "4294967296"; // 1<<32
+        int i        = 0;
+        int ret      = 0;
+        dict_t *dict = dict_new ();
+
+        if (!dict)
+                return NULL;
+
+        for (i = 0; i < argc; i++) {
+                snprintf(index, sizeof(index), "%d", i);
+                ret = dict_set_str (dict, index, argv[i]);
+                if (ret == -1)
+                        break;
+        }
+
+        if (ret) {
+                dict_destroy (dict);
+                dict = NULL;
+        }
+
+        return dict;
+}
+
+int
+cli_cmd_mount_cbk (struct cli_state *state, struct cli_cmd_word *word,
+                   const char **words, int wordcount)
+{
+        rpc_clnt_procedure_t *proc = NULL;
+        call_frame_t *frame        = NULL;
+        int ret                    = -1;
+        dict_t *dict               = NULL;
+        void *dataa[]              = {NULL, NULL};
+
+        if (wordcount < 4) {
+                cli_usage_out (word->pattern);
+                goto out;
+        }
+
+        dict = make_seq_dict (wordcount - 3, (char **)words + 3);
+        if (!dict)
+                goto out;
+
+        dataa[0] = (void *)words[2];
+        dataa[1] = dict;
+
+        proc = &cli_rpc_prog->proctable[GLUSTER_CLI_MOUNT];
+        if (proc && proc->fn) {
+                frame = create_frame (THIS, THIS->ctx->pool);
+                if (!frame)
+                        goto out;
+                ret = proc->fn (frame, THIS, dataa);
+        }
+
+ out:
+        if (dict)
+                dict_unref (dict);
+
+        if (!proc && ret)
+                cli_out ("Mount command failed");
+
+        return ret;
+}
+
+int
+cli_cmd_umount_cbk (struct cli_state *state, struct cli_cmd_word *word,
+                   const char **words, int wordcount)
+{
+        rpc_clnt_procedure_t *proc = NULL;
+        call_frame_t *frame        = NULL;
+        int ret                    = -1;
+        dict_t *dict               = NULL;
+
+        if (!(wordcount == 3 ||
+              (wordcount == 4 && strcmp (words[3], "lazy") == 0))) {
+                cli_usage_out (word->pattern);
+                goto out;
+        }
+
+        dict = dict_new ();
+        if (!dict)
+                goto out;
+
+        ret = dict_set_str (dict, "path", (char *)words[2]);
+        if (ret != 0)
+                goto out;
+        ret = dict_set_int32 (dict, "lazy", wordcount == 4);
+        if (ret != 0)
+                goto out;
+
+        proc = &cli_rpc_prog->proctable[GLUSTER_CLI_UMOUNT];
+        if (proc && proc->fn) {
+                frame = create_frame (THIS, THIS->ctx->pool);
+                if (!frame)
+                        goto out;
+                ret = proc->fn (frame, THIS, dict);
+        }
+
+ out:
+        if (dict)
+                dict_unref (dict);
+
+        if (!proc && ret)
+                cli_out ("Umount command failed");
+
+        return ret;
+}
+
 struct cli_cmd cli_system_cmds[] = {
         { "system:: getspec <VOLID>",
           cli_cmd_getspec_cbk,
@@ -195,6 +305,14 @@ struct cli_cmd cli_system_cmds[] = {
           cli_cmd_getwd_cbk,
           "query glusterd work directory"},
 
+        { "system:: mount <label> <args...>",
+          cli_cmd_mount_cbk,
+          "request a mount"},
+
+        { "system:: umount <path> [lazy]",
+          cli_cmd_umount_cbk,
+          "request an umount"},
+
         { "system:: help",
            cli_cmd_system_help_cbk,
            "display help for system commands"},