Only use runtime config w/ default network ifaces in one test.

runtime/cni_integ_test.go

@@ -135,6 +135,7 @@ func TestCNISupport_Isolated(t *testing.T) {
 
 func TestAutomaticCNISupport_Isolated(t *testing.T) {
 	internal.RequiresIsolation(t)
+	useDefaultNetworkInterfaceRuntimeConfig(t)
 
 	testTimeout := 120 * time.Second
 	ctx, cancel := context.WithTimeout(namespaces.WithNamespace(context.Background(), defaultNamespace), testTimeout)
@@ -355,6 +356,16 @@ func writeCNIConf(path, chainedPluginName, networkName, nameserver string) error
 }`, networkName, nameserver, chainedPluginName)), 0644)
 }
 
+func useDefaultNetworkInterfaceRuntimeConfig(t *testing.T) {
+	t.Helper()
+
+	err := os.RemoveAll(runtimeConfigPath)
+	require.NoError(t, err, "failed to remove existing firecracker containerd runtime config file")
+
+	err = os.Symlink(defaultNetworkInterfaceRuntimeConfigPath, runtimeConfigPath)
+	require.NoError(t, err, "failed to symlink default network interface runtime config")
+}
+
 func runCommand(ctx context.Context, t *testing.T, name string, args ...string) {
 	t.Helper()
 	output, err := exec.CommandContext(ctx, name, args...).CombinedOutput()

runtime/service_integ_test.go

@@ -63,6 +63,9 @@ const (
 	defaultVMRootfsPath = "/var/lib/firecracker-containerd/runtime/default-rootfs.img"
 	defaultVMNetDevName = "eth0"
 	varRunDir           = "/run/firecracker-containerd"
+
+	runtimeConfigPath                        = "/etc/containerd/firecracker-runtime.json"
+	defaultNetworkInterfaceRuntimeConfigPath = "/etc/containerd/firecracker-runtime-defaultnetwork.json"
 )
 
 // Images are presumed by the isolated tests to have already been pulled

tools/docker/Dockerfile

@@ -165,6 +165,7 @@ RUN make -C /firecracker-containerd/internal test-bridged-tap && \
 	chmod a+x /firecracker-containerd/internal/test-bridged-tap
 
 COPY tools/docker/firecracker-runtime.json /etc/containerd/firecracker-runtime.json
+COPY tools/docker/firecracker-runtime-defaultnetwork.json /etc/containerd/firecracker-runtime-defaultnetwork.json
 COPY tools/docker/naive-snapshotter/entrypoint.sh /entrypoint
 
 ENTRYPOINT ["/entrypoint"]

tools/docker/firecracker-runtime-defaultnetwork.json

@@ -0,0 +1,19 @@
+{
+  "firecracker_binary_path": "/usr/local/bin/firecracker",
+  "kernel_image_path": "/var/lib/firecracker-containerd/runtime/default-vmlinux.bin",
+  "kernel_args": "ro console=ttyS0 noapic reboot=k panic=1 pci=off nomodules systemd.journald.forward_to_console systemd.unit=firecracker.target init=/sbin/overlay-init",
+  "root_drive": "/var/lib/firecracker-containerd/runtime/default-rootfs.img",
+  "cpu_count": 1,
+  "cpu_template": "T2",
+  "log_fifo": "/tmp/fc-logs.fifo",
+  "log_level": "Debug",
+  "metrics_fifo": "/tmp/fc-metrics.fifo",
+  "default_network_interfaces": [
+    {
+      "CNIConfig": {
+        "NetworkName": "fcnet",
+        "InterfaceName": "veth0"
+      }
+    }
+  ]
+}

tools/docker/firecracker-runtime.json

@@ -7,13 +7,5 @@
   "cpu_template": "T2",
   "log_fifo": "/tmp/fc-logs.fifo",
   "log_level": "Debug",
-  "metrics_fifo": "/tmp/fc-metrics.fifo",
-  "default_network_interfaces": [
-    {
-      "CNIConfig": {
-        "NetworkName": "fcnet",
-        "InterfaceName": "veth0"
-      }
-    }
-  ]
+  "metrics_fifo": "/tmp/fc-metrics.fifo"
 }