MB-35282: Make cbvdiff use appropriate default user and bucket

Make bucket default to "default" and user default to bucket name.
Follows the precedent set by cbstats.

Not integrating cbvdiff with CliTool at this time due to the slightly
different structure.

Change-Id: Ibff1dde224ba8ad7fe5935844979f2f9a32a266b
Reviewed-on: http://review.couchbase.org/113333
Tested-by: James Harrison <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: jameseh96

engines/ep/management/cbvdiff

@@ -12,11 +12,13 @@ def main():
              usage="usage: %prog ip1:memcachedport1,ip2:memcachedport2",
              version="%prog 1.1")
     parser.add_option('-b', "--bucketName", dest="bucketName",
-                        help="name of bucket. default, if unspecified")
+                        help="name of bucket. default, if unspecified",
+                        default="default")
     parser.add_option('-u', "--user", dest="user",
                         help="Username for authentication")
     parser.add_option('-p', "--bucketPassword", dest="bucketPassword",
-                        help="password to authenticate to bucket")
+                        help="password to authenticate to bucket",
+                        default="")
     stat_cmd = "vbucket-details"
     vbstats = {}
     states = {}
@@ -37,15 +39,15 @@ def main():
         except socket.gaierror as e:
             print('Source %s connection error: %s' % (host, e))
             sys.exit(1)
-        if options.bucketName:
-            password = ""
-            if options.bucketPassword:
-                password = options.bucketPassword
-            try:
-                mc.sasl_auth_plain(options.user, password)
-            except mc_bin_client.MemcachedError:
-                print("Authentication error for %s" % options.bucketName)
-                sys.exit(2)
+
+        user = options.user or options.bucketName
+        password = options.bucketPassword
+
+        try:
+            mc.sasl_auth_plain(user, password)
+        except mc_bin_client.MemcachedError:
+            print("Authentication error for %s" % options.bucketName)
+            sys.exit(2)
         # ----- run cbstats to get the stats as a map ----
         mc.bucket_select(options.bucketName)
         try: