Python unit wrapper

stacks/python/wrapper.py

@@ -0,0 +1,69 @@
+import socket
+import sys
+import os
+import json
+
+YASEN_PATH = os.environ['PROJECTS'] +'/yasen'
+UNITS_CONFIG_PATH = YASEN_PATH +'/configs/units.json'
+
+if len(sys.argv) != 2:
+    print('Usage: wrapper.py unit')
+    exit(1)
+
+unit = sys.argv[1]
+socket_path = '/tmp/unit_%s.sock' % unit
+
+config = json.load(open(UNITS_CONFIG_PATH)).get(unit, None)
+if not config:
+    print('Unknown unit: %s' % unit)
+    exit(1)
+
+unit_path = config['impl'].split('.')
+unit_func = unit_path.pop()
+unit_module = unit_path.pop()
+unit_path = '.'.join(unit_path)
+
+sys.path.append(YASEN_PATH)
+units = __import__(unit_path, fromlist=[unit_module])
+unit = getattr(units, unit_module)
+actor = getattr(unit, unit_func)
+
+def process(input):
+    data = json.loads(input.decode('utf-8'))
+    new_data = actor(data)
+    return json.dumps(new_data).encode('utf-8')
+
+# Make sure the socket does not already exist
+try: os.unlink(socket_path)
+except OSError:
+    if os.path.exists(socket_path): raise
+
+# Create a UDS socket
+sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+
+# Bind the socket to the port
+print('Listening on socket %s' % socket_path)
+sock.bind(socket_path)
+
+# Listen for incoming connections
+sock.listen(1)
+
+BUF_SIZE = 1024
+while True:
+    print('Accepting connections')
+    conn, _ = sock.accept()
+    try:
+        print('New connection')
+        data = b''
+        while True:
+            buf = conn.recv(BUF_SIZE)
+            data += buf
+            if len(buf) < BUF_SIZE:
+                break
+
+        print('Received in total %d bytes' % len(data))
+
+        new_data = process(data)
+        conn.sendall(new_data)
+    finally:
+        conn.close()