TUN-4851: Component tests to sanity check that Proxy DNS and Tunnel are only run when expected

component-tests/test_proxy_dns.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python
+import socket
+from time import sleep
+
+import constants
+from conftest import CfdModes
+from util import start_cloudflared, wait_tunnel_ready, check_tunnel_not_connected
+
+
+# Sanity checks that test that we only run Proxy DNS and Tunnel when we really expect them to be there.
+class TestProxyDns:
+    def test_proxy_dns_with_named_tunnel(self, tmp_path, component_tests_config):
+        run_test_scenario(tmp_path, component_tests_config, CfdModes.NAMED, run_proxy_dns=True)
+
+    def test_proxy_dns_with_classic_tunnel(self, tmp_path, component_tests_config):
+        run_test_scenario(tmp_path, component_tests_config, CfdModes.CLASSIC, run_proxy_dns=True)
+
+    def test_proxy_dns_alone(self, tmp_path, component_tests_config):
+        run_test_scenario(tmp_path, component_tests_config, CfdModes.PROXY_DNS, run_proxy_dns=True)
+
+    def test_named_tunnel_alone(self, tmp_path, component_tests_config):
+        run_test_scenario(tmp_path, component_tests_config, CfdModes.NAMED, run_proxy_dns=False)
+
+    def test_classic_tunnel_alone(self, tmp_path, component_tests_config):
+        run_test_scenario(tmp_path, component_tests_config, CfdModes.CLASSIC, run_proxy_dns=False)
+
+
+def run_test_scenario(tmp_path, component_tests_config, cfd_mode, run_proxy_dns):
+    expect_proxy_dns = run_proxy_dns
+    expect_tunnel = False
+
+    if cfd_mode == CfdModes.NAMED:
+        expect_tunnel = True
+        pre_args = ["tunnel"]
+        args = ["run"]
+    elif cfd_mode == CfdModes.CLASSIC:
+        expect_tunnel = True
+        pre_args = []
+        args = []
+    elif cfd_mode == CfdModes.PROXY_DNS:
+        expect_proxy_dns = True
+        pre_args = []
+        args = ["proxy-dns", "--port", str(constants.PROXY_DNS_PORT)]
+    else:
+        assert False, f"Unknown cfd_mode {cfd_mode}"
+
+    config = component_tests_config(cfd_mode=cfd_mode, run_proxy_dns=run_proxy_dns)
+    with start_cloudflared(tmp_path, config, cfd_pre_args=pre_args, cfd_args=args, new_process=True, capture_output=False):
+        if expect_tunnel:
+            wait_tunnel_ready()
+        else:
+            check_tunnel_not_connected()
+        verify_proxy_dns(expect_proxy_dns)
+
+
+def verify_proxy_dns(should_be_running):
+    # Wait for the Proxy DNS listener to come up.
+    sleep(constants.BACKOFF_SECS)
+    had_failure = False
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        sock.connect(('localhost', constants.PROXY_DNS_PORT))
+        sock.send(b"anything")
+    except:
+        if should_be_running:
+            assert False, "Expected Proxy DNS to be running, but it was not."
+        had_failure = True
+    finally:
+        sock.close()
+
+    if not should_be_running and not had_failure:
+        assert False, "Proxy DNS should not have been running, but it was."