add test for remote ssh commands

pkgs/clan-cli/tests/ports.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+
+import socket
+
+import pytest
+
+NEXT_PORT = 10000
+
+
+def check_port(port: int) -> bool:
+    tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    with tcp, udp:
+        try:
+            tcp.bind(("127.0.0.1", port))
+            udp.bind(("127.0.0.1", port))
+            return True
+        except socket.error:
+            return False
+
+
+def check_port_range(port_range: range) -> bool:
+    for port in port_range:
+        if not check_port(port):
+            return False
+    return True
+
+
+class Ports:
+    def allocate(self, num: int) -> int:
+        """
+        Allocates
+        """
+        global NEXT_PORT
+        while NEXT_PORT + num <= 65535:
+            start = NEXT_PORT
+            NEXT_PORT += num
+            if not check_port_range(range(start, NEXT_PORT)):
+                continue
+            return start
+        raise Exception("cannot find enough free port")
+
+
+@pytest.fixture
+def ports() -> Ports:
+    return Ports()