MB-34149: Handle master password correctly.

With the new erlang distribution mechanism implemented in cluster manager,
the master password command in the CLI stopped working. This change
passes in the necessary arguments to the erlang VM that will be started
by the CLI to set the master password.

Earlier the CLI was scraping the stdout of the sub-process to determine
the success/failure of the command. Now, the CLI will use the discrete
exit codes returned by babysitter's helper API to determine success/failure
of the command.

This change is dependent on the following change:
http://review.couchbase.org/#/c/111937/

Change-Id: I7b531bf26c385f0632ec3793a5ef22f958c26aec
Reviewed-on: http://review.couchbase.org/111938
Reviewed-by: Patrick Varley <patrick@couchbase.com>
Tested-by: Ajit Yagaty <ajit.yagaty@couchbase.com>
Tested-by: Build Bot <build@couchbase.com>

Author: ajityagaty

cbmgr.py

@@ -35,6 +35,7 @@
 
 CB_BIN_PATH = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", "bin"))
 CB_ETC_PATH = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", "etc", "couchbase"))
+CB_LIB_PATH = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", "lib"))
 
 # On MacOS the config is store in the users home directory
 if platform.system() == "Darwin":
@@ -1404,37 +1405,41 @@ def execute(self, opts):
             nodefile = os.path.join(opts.config_path, "couchbase-server.babysitter.node")
             node = _exit_on_file_read_failure(nodefile).rstrip()
 
-            self.prompt_for_master_pwd(node, cookie, opts.send_password)
+            self.prompt_for_master_pwd(node, cookie, opts.send_password, opts.config_path)
         else :
             _exitIfErrors(["No parameters set"])
 
-    def prompt_for_master_pwd(self, node, cookie, password):
+    def prompt_for_master_pwd(self, node, cookie, password, cb_cfg_path):
+        ns_server_ebin_path = os.path.join(CB_LIB_PATH, "ns_server", "erlang", "lib", "ns_server", "ebin")
+        babystr_ebin_path = os.path.join(CB_LIB_PATH, "ns_server", "erlang", "lib", "ns_babysitter", "ebin")
+        inetrc_file = os.path.join(CB_ETC_PATH, "hosts.cfg")
+        dist_cfg_file = os.path.join(cb_cfg_path, "config", "dist_cfg")
+
         if password == '':
             password = getpass.getpass("\nEnter master password:")
-        password = "\"" + password.replace("\\", "\\\\").replace("\"", "\\\"") + "\""
-
-        randChars = ''.join(random.choice(string.ascii_letters) for i in range(20))
-        name = f'cb-{randChars}@127.0.0.1'
 
-        instr = "Res = rpc:call('" + node + "', encryption_service, set_password, [" \
-                + password + "]), io:format(\"~p~n\", [Res])."
-        args = ["-noinput", "-name", name, "-setcookie", cookie, "-eval", \
-                instr, "-run", "init", "stop"]
+        name = f'executioner@cb.local'
+        args = ['-pa', ns_server_ebin_path, babystr_ebin_path, '-noinput', '-name', name, \
+                '-proto_dist', 'cb', '-epmd_module', 'cb_epmd', \
+                '-kernel', 'inetrc', f'"{inetrc_file}"', 'dist_config_file', f'"{dist_cfg_file}"', \
+                '-setcookie', cookie, \
+                '-run', 'encryption_service', 'remote_set_password', node, password]
 
-        res, error = self.run_process("erl", args)
-        res = res.decode().strip()
+        rc, out, err = self.run_process("erl", args)
 
-        if res == "ok":
+        if rc == 0:
             print("SUCCESS: Password accepted. Node started booting.")
-        elif res == "retry":
+        elif rc == 1:
             print("Incorrect password.")
-            self.prompt_for_master_pwd(node, cookie, '')
-        elif res == "{error,not_allowed}":
+            self.prompt_for_master_pwd(node, cookie, '', cb_cfg_path)
+        elif rc == 2:
             _exitIfErrors(["Password was already supplied"])
-        elif res == "{badrpc,nodedown}":
+        elif rc == 3:
             _exitIfErrors(["The node is down"])
-        else:
+        elif rc == 4:
             _exitIfErrors(["Incorrect password. Node shuts down."])
+        else:
+            _exitIfErrors([f'Unknown error: {out}, {err}'])
 
     def run_process(self, name, args):
         try:
@@ -1447,7 +1452,7 @@ def run_process(self, name, args):
             error = p.stderr.read()
             p.wait()
             rc = p.returncode
-            return output, error
+            return rc, output, error
         except OSError:
             _exitIfErrors([f'Could not locate the {name} executable'])