fix(tests): E2E tests use isolated config and instance-scoped container cleanup

Two issues were causing E2E tests to fail:

1. Tests loaded user's real ~/.mcpproxy/mcp_config.json instead of a clean
   test config, causing connection attempts to 15+ real upstream servers.
   Fixed by creating minimal config files in test temp directories.

2. Docker container cleanup affected ALL mcpproxy instances on the machine,
   not just the test instance. This caused 15+ second shutdown delays as
   the test server tried to clean up containers from other running instances.
   Fixed by filtering container operations by instance ID label.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: technicalpickles

internal/server/info_shutdown_e2e_test.go

@@ -36,6 +36,15 @@ func TestInfoEndpoint(t *testing.T) {
 	err := os.Chmod(tempDir, 0700)
 	require.NoError(t, err, "Failed to set secure permissions on temp directory")
 
+	// Create a minimal config file to avoid loading user's real config
+	configPath := filepath.Join(tempDir, "mcp_config.json")
+	minimalConfig := `{
+		"listen": "127.0.0.1:0",
+		"mcpServers": [],
+		"docker_isolation": {"enabled": false}
+	}`
+	require.NoError(t, os.WriteFile(configPath, []byte(minimalConfig), 0600))
+
 	// Find available port
 	ln, err := net.Listen("tcp", ":0")
 	require.NoError(t, err)
@@ -49,6 +58,7 @@ func TestInfoEndpoint(t *testing.T) {
 	defer cancel()
 
 	cmd := exec.CommandContext(ctx, binaryPath, "serve",
+		"--config", configPath,
 		"--data-dir", tempDir,
 		"--listen", listenAddr)
 
@@ -150,6 +160,15 @@ func TestGracefulShutdownNoPanic(t *testing.T) {
 	err := os.Chmod(tempDir, 0700)
 	require.NoError(t, err, "Failed to set secure permissions on temp directory")
 
+	// Create a minimal config file to avoid loading user's real config
+	configPath := filepath.Join(tempDir, "mcp_config.json")
+	minimalConfig := `{
+		"listen": "127.0.0.1:0",
+		"mcpServers": [],
+		"docker_isolation": {"enabled": false}
+	}`
+	require.NoError(t, os.WriteFile(configPath, []byte(minimalConfig), 0600))
+
 	// Find available port
 	ln, err := net.Listen("tcp", ":0")
 	require.NoError(t, err)
@@ -163,6 +182,7 @@ func TestGracefulShutdownNoPanic(t *testing.T) {
 	defer cancel()
 
 	cmd := exec.CommandContext(ctx, binaryPath, "serve",
+		"--config", configPath,
 		"--data-dir", tempDir,
 		"--listen", listenAddr,
 		"--log-level", "debug")
@@ -244,13 +264,23 @@ func TestSocketInfoEndpoint(t *testing.T) {
 	err := os.Chmod(tempDir, 0700)
 	require.NoError(t, err, "Failed to set secure permissions on temp directory")
 
+	// Create a minimal config file to avoid loading user's real config
+	configPath := filepath.Join(tempDir, "mcp_config.json")
+	minimalConfig := `{
+		"listen": "127.0.0.1:0",
+		"mcpServers": [],
+		"docker_isolation": {"enabled": false}
+	}`
+	require.NoError(t, os.WriteFile(configPath, []byte(minimalConfig), 0600))
+
 	socketPath := filepath.Join(tempDir, "mcpproxy.sock")
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
 	// Start server with socket enabled
 	cmd := exec.CommandContext(ctx, binaryPath, "serve",
+		"--config", configPath,
 		"--data-dir", tempDir,
 		"--listen", "127.0.0.1:0", // Random port for HTTP
 		"--enable-socket", "true")

internal/upstream/core/instance.go

@@ -32,6 +32,11 @@ func getInstanceID() string {
 	return instanceID
 }
 
+// GetInstanceID returns the unique identifier for this mcpproxy instance (exported for use by manager)
+func GetInstanceID() string {
+	return getInstanceID()
+}
+
 // loadInstanceID attempts to load the instance ID from disk
 func loadInstanceID() (string, error) {
 	instanceFile := filepath.Join(os.TempDir(), "mcpproxy-instance-id")

internal/upstream/manager.go

@@ -616,16 +616,19 @@ func (m *Manager) cleanupAllManagedContainers(ctx context.Context) {
 
 // ForceCleanupAllContainers is a public wrapper for emergency container cleanup
 // This is called when graceful shutdown fails and containers must be force-removed
+// Only removes containers owned by THIS instance (matching instance ID)
 func (m *Manager) ForceCleanupAllContainers() {
-	m.logger.Warn("Force cleanup requested - removing all managed containers immediately")
+	m.logger.Warn("Force cleanup requested - removing all managed containers for this instance")
 
 	// Create a short-lived context for force cleanup (30 seconds max)
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
 
-	// Find all containers with our management label
+	// Find all containers with our management label AND our instance ID
+	instanceID := core.GetInstanceID()
 	listCmd := exec.CommandContext(ctx, "docker", "ps", "-a",
 		"--filter", "label=com.mcpproxy.managed=true",
+		"--filter", fmt.Sprintf("label=com.mcpproxy.instance=%s", instanceID),
 		"--format", "{{.ID}}\t{{.Names}}")
 
 	output, err := listCmd.Output()
@@ -1141,14 +1144,16 @@ func (m *Manager) DisconnectAll() error {
 	return nil
 }
 
-// HasDockerContainers checks if any Docker containers are actually running
+// HasDockerContainers checks if any Docker containers owned by THIS instance are actually running
 func (m *Manager) HasDockerContainers() bool {
-	// Check if any containers with our labels are actually running
+	// Check if any containers with our labels AND our instance ID are running
 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 	defer cancel()
 
+	instanceID := core.GetInstanceID()
 	listCmd := exec.CommandContext(ctx, "docker", "ps", "-q",
-		"--filter", "label=com.mcpproxy.managed=true")
+		"--filter", "label=com.mcpproxy.managed=true",
+		"--filter", fmt.Sprintf("label=com.mcpproxy.instance=%s", instanceID))
 
 	output, err := listCmd.Output()
 	if err != nil {