Function TestNetworkWithDefaultNameAlreadyExists

pkg/netutil/netutil_test.go:307–368

Tests whether nerdctl skips the creation of the default network if a network bearing the default network name already exists in a non-nerdctl-managed network config file.

(t *testing.T)

// network bearing the default network name already exists in a
// non-nerdctl-managed network config file.
func TestNetworkWithDefaultNameAlreadyExists(t *testing.T) {
	// We create a tempdir for the CNI conf path to ensure an empty env for this test.
	cniConfTestDir := t.TempDir()
	cniEnv := CNIEnv{
		Path:        t.TempDir(), // irrelevant for this test
		NetconfPath: cniConfTestDir,
	}

	// Ensure no default network config is not present.
	defaultNetConf, err := cniEnv.GetDefaultNetworkConfig()
	assert.NilError(t, err)
	assert.Assert(t, defaultNetConf == nil)

	// Manually define and write a network config file.
	values := map[string]string{
		"network_name": DefaultNetworkName,
		"subnet":       "10.7.1.1/24",
		"gateway":      "10.7.1.1",
	}
	tpl, err := template.New("test").Parse(preExistingNetworkConfigTemplate)
	assert.NilError(t, err)
	buf := &bytes.Buffer{}
	assert.NilError(t, tpl.ExecuteTemplate(buf, "test", values))

	// Filename is irrelevant as long as it's not nerdctl's.
	testConfFile := filepath.Join(cniConfTestDir, fmt.Sprintf("%s.conf", testutil.Identifier(t)))
	err = filesystem.WriteFile(testConfFile, buf.Bytes(), 0600)
	assert.NilError(t, err)

	// Check network is detected.
	netConfs, err := cniEnv.NetworkList()
	assert.NilError(t, err)
	assert.Assert(t, len(netConfs) > 0)

	var listedDefaultNetConf *NetworkConfig
	for _, netConf := range netConfs {
		if netConf.Name == DefaultNetworkName {
			listedDefaultNetConf = netConf
			break
		}
	}
	assert.Assert(t, listedDefaultNetConf != nil)

	defaultNetConf, err = cniEnv.GetDefaultNetworkConfig()
	assert.NilError(t, err)
	assert.Assert(t, defaultNetConf != nil)
	assert.Assert(t, defaultNetConf.File == testConfFile)

	err = cniEnv.ensureDefaultNetworkConfig("")
	assert.NilError(t, err)

	netConfs, err = cniEnv.NetworkList()
	assert.NilError(t, err)
	defaultNamedNetworksFileDefinitions := []string{}
	for _, netConf := range netConfs {
		if netConf.Name == DefaultNetworkName {
			defaultNamedNetworksFileDefinitions = append(defaultNamedNetworksFileDefinitions, netConf.File)
		}