Repair managed nginx listeners and verify reload acceptance

tests/regression/nginx-listener-reload.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""Exercise the exact bootstrap reload shell with isolated fake service commands.
+
+No actual nginx/systemd command is invoked. A successful reload signal must not
+count as acceptance if the master leaves its old workers running.
+"""
+from pathlib import Path
+import os
+import subprocess
+import tempfile
+import unittest
+
+ROOT = Path(__file__).resolve().parents[2]
+SOURCE = ROOT / 'core/archipelago/src/bootstrap.rs'
+
+
+class ReloadAcceptance(unittest.TestCase):
+    def run_reload(self, mode):
+        source = SOURCE.read_text()
+        function = source.split('async fn reload_nginx_checked()', 1)[1]
+        script = function.split('r#"', 1)[1].split('"#;', 1)[0]
+        with tempfile.TemporaryDirectory(prefix='nginx-reload-fixture-') as directory:
+            root = Path(directory)
+            commands = {
+                'systemctl': '''#!/bin/sh
+if [ "$1" = show ]; then echo 23; exit 0; fi
+[ "$1" = reload ] || exit 90
+[ "$RELOAD_CASE" != signal_failure ] || exit 1
+touch "$FIXTURE_ROOT/reloaded"
+''',
+                'nginx': '#!/bin/sh\n[ "$RELOAD_CASE" != invalid_config ]\n',
+                'ps': '''#!/bin/sh
+[ "$1" = --ppid ] && [ "$2" = 23 ] || exit 91
+if [ "$RELOAD_CASE" = accepted ] && [ -f "$FIXTURE_ROOT/reloaded" ]; then
+    printf '102 nginx: worker process\n103 nginx: worker process\n'
+elif [ "$RELOAD_CASE" = shutting_down ] && [ -f "$FIXTURE_ROOT/reloaded" ]; then
+    printf '100 nginx: worker process\n101 nginx: worker process\n102 nginx: worker process is shutting down\n'
+else
+    printf '100 nginx: worker process\n101 nginx: worker process\n'
+fi
+''',
+                'sleep': '#!/bin/sh\nexit 0\n',
+            }
+            for name, body in commands.items():
+                path = root / name
+                path.write_text(body)
+                path.chmod(0o700)
+            env = {'PATH': f'{root}:/usr/bin:/bin', 'FIXTURE_ROOT': str(root),
+                   'RELOAD_CASE': mode, 'LC_ALL': 'C'}
+            result = subprocess.run(['/bin/sh', '-c', script], env=env,
+                                    capture_output=True, text=True, timeout=5)
+            signalled = (root / 'reloaded').exists()
+            return result.returncode, signalled
+
+    def test_new_workers_accept_reload(self):
+        self.assertEqual(self.run_reload('accepted'), (0, True))
+
+    def test_successful_signal_without_new_workers_is_failure(self):
+        code, signalled = self.run_reload('bind_failure')
+        self.assertNotEqual(code, 0)
+        self.assertTrue(signalled)
+
+    def test_shutting_down_workers_do_not_prove_acceptance(self):
+        self.assertNotEqual(self.run_reload('shutting_down')[0], 0)
+
+    def test_invalid_config_never_signals(self):
+        code, signalled = self.run_reload('invalid_config')
+        self.assertNotEqual(code, 0)
+        self.assertFalse(signalled)
+
+    def test_failed_signal_is_failure(self):
+        self.assertNotEqual(self.run_reload('signal_failure')[0], 0)
+
+
+if __name__ == '__main__':
+    unittest.main()