Initial commit

colony/transport/discover.py

@@ -0,0 +1,32 @@
+import socket
+import struct
+
+class Discover:
+    DISCOVER_PORT = 28149
+    MAGIC = b"OK"
+
+    @staticmethod
+    def listen(real_port, host="0.0.0.0"):
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        s.bind((host, Discover.DISCOVER_PORT))
+        s.listen()
+
+        while True:
+            conn, _ = s.accept()
+            try:
+                data = conn.recv(2)
+                if data == Discover.MAGIC:
+                    conn.sendall(struct.pack("!H", real_port))
+            finally:
+                conn.close()
+
+    @staticmethod
+    def request(target_host, timeout=3):
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.settimeout(timeout)
+        s.connect((target_host, Discover.DISCOVER_PORT))
+        s.sendall(Discover.MAGIC)
+        data = s.recv(2)
+        s.close()
+        return struct.unpack("!H", data)[0]