jsonrpc: add Python with statement support

The JSONRPCClient class now support the with statement. From now on the
__del__() method is changed to close() and user need to call it manually
at object disposal or use the 'with' Python statement.

Change-Id: I74afd93d411b9596ab8f9523c54a4a7523eec5e5
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/444686
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Pawel Kaminski <pawelx.kaminski@intel.com>

scripts/rpc.py

@@ -1737,10 +1737,11 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse
 
     args = parser.parse_args()
 
-    try:
-        args.client = rpc.client.JSONRPCClient(args.server_addr, args.port, args.timeout, log_level=getattr(logging, args.verbose.upper()))
-        args.func(args)
-    except JSONRPCException as ex:
-        print("Exception:")
-        print(ex.message)
-        exit(1)
+    with rpc.client.JSONRPCClient(args.server_addr, args.port, args.timeout, log_level=getattr(logging, args.verbose.upper())) as client:
+        try:
+            args.client = client
+            args.func(args)
+        except JSONRPCException as ex:
+            print("Exception:")
+            print(ex.message)
+            exit(1)

scripts/rpc/client.py

@@ -48,6 +48,12 @@ class JSONRPCClient(object):
             raise JSONRPCException("Error while connecting to %s\n"
                                    "Error details: %s" % (addr, ex))
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        self.close()
+
     def get_logger(self):
         return self._logger
 
@@ -61,9 +67,11 @@ class JSONRPCClient(object):
         self._logger.setLevel(lvl)
         self._logger.info("Log level set to %s", lvl)
 
-    def __del__(self):
+    def close(self):
         if getattr(self, "sock", None):
+            self.sock.shutdown(socket.SHUT_RDWR)
             self.sock.close()
+            self.sock = None
 
     def add_request(self, method, params):
         self._request_id += 1

scripts/spdkcli.py

@@ -6,6 +6,7 @@ from os import getuid
 from rpc.client import JSONRPCException
 from configshell_fb import ConfigShell, shell, ExecutionError
 from spdkcli import UIRoot
+import rpc.client
 from pyparsing import (alphanums, Optional, Suppress, Word, Regex,
                        removeQuotes, dblQuotedString, OneOrMore)
 
@@ -43,29 +44,30 @@ def main():
                         help="commands to execute by SPDKCli as one-line command")
     args = parser.parse_args()
 
-    root_node = UIRoot(args.socket, spdk_shell)
-    root_node.verbose = args.verbose
-    try:
-        root_node.refresh()
-    except BaseException:
-        pass
-
-    if len(args.commands) > 0:
+    with rpc.client.JSONRPCClient(args.socket) as client:
+        root_node = UIRoot(client, spdk_shell)
+        root_node.verbose = args.verbose
         try:
-            spdk_shell.interactive = False
-            spdk_shell.run_cmdline(" ".join(args.commands))
-        except Exception as e:
-            sys.stderr.write("%s\n" % e)
-            sys.exit(1)
-        sys.exit(0)
+            root_node.refresh()
+        except BaseException:
+            pass
 
-    spdk_shell.con.display("SPDK CLI v0.1")
-    spdk_shell.con.display("")
-    while not spdk_shell._exit:
-        try:
-            spdk_shell.run_interactive()
-        except (JSONRPCException, ExecutionError) as e:
-            spdk_shell.log.error("%s" % e)
+        if len(args.commands) > 0:
+            try:
+                spdk_shell.interactive = False
+                spdk_shell.run_cmdline(" ".join(args.commands))
+            except Exception as e:
+                sys.stderr.write("%s\n" % e)
+                sys.exit(1)
+            sys.exit(0)
+
+        spdk_shell.con.display("SPDK CLI v0.1")
+        spdk_shell.con.display("")
+        while not spdk_shell._exit:
+            try:
+                spdk_shell.run_interactive()
+            except (JSONRPCException, ExecutionError) as e:
+                spdk_shell.log.error("%s" % e)
 
 
 if __name__ == "__main__":

scripts/spdkcli/ui_root.py

@@ -10,14 +10,14 @@ class UIRoot(UINode):
     """
     Root node for CLI menu tree structure. Refreshes running config on startup.
     """
-    def __init__(self, s, shell):
+    def __init__(self, client, shell):
         UINode.__init__(self, "/", shell=shell)
         self.current_bdevs = []
         self.current_lvol_stores = []
         self.current_vhost_ctrls = []
         self.current_nvmf_transports = []
         self.current_nvmf_subsystems = []
-        self.set_rpc_target(s)
+        self.set_rpc_target(client)
         self.verbose = False
         self.is_init = self.check_init()
         self.methods = []
@@ -45,8 +45,8 @@ class UIRoot(UINode):
         if self.has_subsystem("iscsi"):
             UIISCSI(self)
 
-    def set_rpc_target(self, s):
-        self.client = rpc.client.JSONRPCClient(s)
+    def set_rpc_target(self, client):
+        self.client = client
 
     def print_array(self, a):
         return " ".join(a)

test/json_config/clear_config.py

@@ -209,9 +209,10 @@ if __name__ == "__main__":
 
     args = parser.parse_args()
 
-    try:
-        args.client = rpc.client.JSONRPCClient(args.server_addr, args.port, args.timeout, log_level=getattr(logging, args.verbose.upper()))
-    except JSONRPCException as ex:
-        print((ex.message))
-        exit(1)
-    args.func(args)
+    with rpc.client.JSONRPCClient(args.server_addr, args.port, args.timeout, log_level=getattr(logging, args.verbose.upper())) as client:
+        try:
+            args.client = client
+            args.func(args)
+        except JSONRPCException as ex:
+            print((ex.message))
+            exit(1)