[spp] [PATCH 1/9] controller: add spp-ctl client for SPP controller

[ogawa.yasufumi@lab.ntt.co.jp]

From: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>

Add SppCtlClient class which is a utility to create requests and
responses for spp-ctl.

Signed-off-by: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>
---
 src/controller/spp_ctl_client.py | 58 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/controller/spp_ctl_client.py

diff --git a/src/controller/spp_ctl_client.py b/src/controller/spp_ctl_client.py
new file mode 100644
index 0000000..6de1ae4
--- /dev/null
+++ b/src/controller/spp_ctl_client.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2018 Nippon Telegraph and Telephone Corporation
+
+import requests
+
+
+class SppCtlClient(object):
+
+    def __init__(self):
+        api_ver = 'v1'
+        ip_addr = '127.0.0.1'
+        port = 7777
+        self.base_url = 'http://%s:%d/%s' % (ip_addr, port, api_ver)
+
+    def request_handler(func):
+        """Request handler for spp-ctl.
+
+        Decorator for handling a http request of 'requests' library.
+        It receives one of the methods 'get', 'put', 'post' or 'delete'
+        as 'func' argment.
+        """
+
+        def wrapper(self, *args, **kwargs):
+            try:
+                res = func(self, *args, **kwargs)
+
+                # TODO(yasufum) revise print message to more appropriate
+                # for spp.py.
+                if res.status_code == 400:
+                    print('Syntax or lexical error, or SPP returns' +
+                          'error for the request.')
+                elif res.status_code == 404:
+                    print('URL is not supported, or no SPP process' +
+                          'of client-id in a URL.')
+                elif res.status_code == 500:
+                    print('System error occured in spp-ctl.')
+
+                return res
+            except requests.exceptions.ConnectionError:
+                print('Error: Failed to connect to spp-ctl.')
+                return None
+        return wrapper
+
+    @request_handler
+    def get(self, req):
+        url = '%s/%s' % (self.base_url, req)
+        return requests.get(url)
+
+    @request_handler
+    def put(self, req, params):
+        url = '%s/%s' % (self.base_url, req)
+        return requests.put(url, json=params)
+
+    @request_handler
+    def delete(self, req):
+        url = '%s/%s' % (self.base_url, req)
+        return requests.delete(url)
-- 
2.13.1