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

component-tests/config.py

@@ -3,7 +3,7 @@ import copy
 
 from dataclasses import dataclass, InitVar
 
-from constants import METRICS_PORT
+from constants import METRICS_PORT, PROXY_DNS_PORT
 
 # frozen=True raises exception when assigning to fields. This emulates immutability
 
@@ -93,3 +93,12 @@ class ClassicTunnelConfig(ClassicTunnelBaseConfig):
 
     def get_url(self):
         return "https://" + self.hostname
+
+
+@dataclass(frozen=True)
+class ProxyDnsConfig(BaseConfig):
+    full_config = {
+        "port": PROXY_DNS_PORT,
+        "no-autoupdate": True,
+    }
+

component-tests/conftest.py

@@ -1,14 +1,21 @@
 import os
+from enum import Enum, auto
+from time import sleep
+
 import pytest
 import yaml
 
-from time import sleep
+from config import NamedTunnelConfig, ClassicTunnelConfig, ProxyDnsConfig
-
+from constants import BACKOFF_SECS, PROXY_DNS_PORT
-from config import NamedTunnelConfig, ClassicTunnelConfig
-from constants import BACKOFF_SECS
 from util import LOGGER
 
 
+class CfdModes(Enum):
+    NAMED = auto()
+    CLASSIC = auto()
+    PROXY_DNS = auto()
+
+
 @pytest.fixture(scope="session")
 def component_tests_config():
     config_file = os.getenv("COMPONENT_TESTS_CONFIG")
@@ -19,22 +26,30 @@ def component_tests_config():
         config = yaml.safe_load(stream)
         LOGGER.info(f"component tests base config {config}")
 
-        def _component_tests_config(additional_config={}, named_tunnel=True):
+        def _component_tests_config(additional_config={}, cfd_mode=CfdModes.NAMED, run_proxy_dns=True):
+            if run_proxy_dns:
+                # Regression test for TUN-4177, running with proxy-dns should not prevent tunnels from running.
+                # So we run all tests with it.
+                additional_config["proxy-dns"] = True
+                additional_config["proxy-dns-port"] = PROXY_DNS_PORT
+            else:
+                additional_config.pop("proxy-dns", None)
+                additional_config.pop("proxy-dns-port", None)
 
-            # Regression test for TUN-4177, running with proxy-dns should not prevent tunnels from running
+            if cfd_mode is CfdModes.NAMED:
-            additional_config["proxy-dns"] = True
-            additional_config["proxy-dns-port"] = 9053
-
-            if named_tunnel:
                 return NamedTunnelConfig(additional_config=additional_config,
                                          cloudflared_binary=config['cloudflared_binary'],
                                          tunnel=config['tunnel'],
                                          credentials_file=config['credentials_file'],
                                          ingress=config['ingress'])
-
+            elif cfd_mode is CfdModes.CLASSIC:
-            return ClassicTunnelConfig(
+                return ClassicTunnelConfig(
-                additional_config=additional_config, cloudflared_binary=config['cloudflared_binary'],
+                    additional_config=additional_config, cloudflared_binary=config['cloudflared_binary'],
-                hostname=config['classic_hostname'], origincert=config['origincert'])
+                    hostname=config['classic_hostname'], origincert=config['origincert'])
+            elif cfd_mode is CfdModes.PROXY_DNS:
+                return ProxyDnsConfig(cloudflared_binary=config['cloudflared_binary'])
+            else:
+                raise Exception(f"Unknown cloudflared mode {cfd_mode}")
 
         return _component_tests_config
 

component-tests/constants.py

@@ -1,3 +1,5 @@
 METRICS_PORT = 51000
 MAX_RETRIES = 5
 BACKOFF_SECS = 7
+
+PROXY_DNS_PORT = 9053

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."

component-tests/test_reconnect.py

@@ -6,6 +6,7 @@ from time import sleep
 import pytest
 from flaky import flaky
 
+from conftest import CfdModes
 from util import start_cloudflared, wait_tunnel_ready, check_tunnel_not_connected
 
 
@@ -27,8 +28,7 @@ class TestReconnect:
     def test_classic_reconnect(self, tmp_path, component_tests_config):
         extra_config = copy.copy(self.extra_config)
         extra_config["hello-world"] = True
-        config = component_tests_config(
+        config = component_tests_config(additional_config=extra_config, cfd_mode=CfdModes.CLASSIC)
-            additional_config=extra_config, named_tunnel=False)
         with start_cloudflared(tmp_path, config, cfd_args=[], new_process=True, allow_input=True, capture_output=False) as cloudflared:
             self.assert_reconnect(config, cloudflared, 1)
 

component-tests/test_service.py

@@ -8,6 +8,7 @@ from pathlib import Path
 import pytest
 
 import test_logging
+from conftest import CfdModes
 from util import start_cloudflared, wait_tunnel_ready
 
 
@@ -34,7 +35,7 @@ class TestServiceMode:
             "hello-world": True,
             "logfile": str(log_file),
         }
-        config = component_tests_config(additional_config=additional_config, named_tunnel=False)
+        config = component_tests_config(additional_config=additional_config, cfd_mode=CfdModes.CLASSIC)
 
         def assert_log_file():
             test_logging.assert_log_in_file(log_file)
@@ -52,7 +53,7 @@ class TestServiceMode:
             "loglevel": "debug",
             "log-directory": str(log_dir),
         }
-        config = component_tests_config(additional_config=additional_config, named_tunnel=False)
+        config = component_tests_config(additional_config=additional_config, cfd_mode=CfdModes.CLASSIC)
 
         def assert_rotating_log():
             test_logging.assert_log_to_dir(config, log_dir)