[multi-DB] Part 4: add sonic-db-cli to replace redis-cli (#54)

* [multi-DB] Part 4: add sonic-db-cli to replace redis-cli
* use SonicV2Connector instead and fix previous if condition typo
* remove unused import
* use_unix_socket_path set to False by default to avoid unnecessary failed
* update Usage message and add example under -h
* remove logging and update usage msg

Author: dzhangalibaba

setup.py

@@ -14,6 +14,7 @@
     package_dir={'swsssdk': 'src/swsssdk'},
     packages=['swsssdk'],
     package_data={'swsssdk': ['config/*.json']},
+    scripts=['src/swsssdk/scripts/sonic-db-cli'],
     license='Apache 2.0',
     author='SONiC Team',
     author_email='[email protected]',

src/swsssdk/dbconnector.py

@@ -103,15 +103,15 @@ def get_separator(db_name):
         return SonicDBConfig._sonic_db_config["DATABASES"][db_name]["separator"]
 
 class SonicV2Connector(DBInterface):
-    def __init__(self, use_unix_socket_path=True, **kwargs):
+    def __init__(self, use_unix_socket_path=False, **kwargs):
         super(SonicV2Connector, self).__init__(**kwargs)
         self.use_unix_socket_path = use_unix_socket_path
         for db_name in self.get_db_list():
             # set a database name as a constant value attribute.
             setattr(self, db_name, db_name)
 
     def connect(self, db_name, retry_on=True):
-        if self.use_unix_socket_path == False:
+        if self.use_unix_socket_path:
             self.redis_kwargs["unix_socket_path"] = self.get_db_socket(db_name)
             self.redis_kwargs["host"] = None
             self.redis_kwargs["port"] = None

src/swsssdk/scripts/sonic-db-cli

@@ -0,0 +1,23 @@
+#!/usr/bin/python
+import sys
+import swsssdk
+
+argc = len(sys.argv)
+if argc == 2 and sys.argv[1] == '-h':
+    print "Example 1: sonic-db-cli CONFIG_DB keys *"
+    print "Example 2: sonic-db-cli APPL_DB HGETALL VLAN_TABLE:Vlan10"
+    print "Example 3: sonic-db-cli APPL_DB HGET VLAN_TABLE:Vlan10 mtu"
+elif argc < 3:
+    msg = "'Usage: sonic-db-cli <db_name> <cmd> [arg [arg ...]]'. See 'sonic-db-cli -h' for detail examples."
+    print >> sys.stderr, msg
+else:
+    dbname = sys.argv[1]
+    dbconn = swsssdk.SonicV2Connector(use_unix_socket_path=False)
+    try:
+        dbconn.connect(dbname)
+    except RuntimeError:
+        msg = "Invalid database name input : '{}'".format(sys.argv[1])
+        print >> sys.stderr, msg
+    else:
+        client = dbconn.get_redis_client(dbname)
+        print client.execute_command(" ".join(sys.argv[2:]))