Cns windows aks (#1059)

* chore: add in some functionality for CNS on windows host process pods

cni/client/client.go

@@ -9,14 +9,11 @@ import (
 	"github.com/Azure/azure-container-networking/cni"
 	"github.com/Azure/azure-container-networking/cni/api"
 	"github.com/Azure/azure-container-networking/log"
+	"github.com/Azure/azure-container-networking/platform"
 	semver "github.com/hashicorp/go-version"
 	utilexec "k8s.io/utils/exec"
 )
 
-const (
-	azureVnetExecutable = "/opt/cni/bin/azure-vnet"
-)
-
 type Client interface {
 	GetEndpointState() (*api.AzureCNIState, error)
 }
@@ -32,7 +29,7 @@ func New(exec utilexec.Interface) *client {
 }
 
 func (c *client) GetEndpointState() (*api.AzureCNIState, error) {
-	cmd := c.exec.Command(azureVnetExecutable)
+	cmd := c.exec.Command(platform.CNIBinaryPath)
 
 	envs := os.Environ()
 	cmdenv := fmt.Sprintf("%s=%s", cni.Cmd, cni.CmdGetEndpointsState)
@@ -54,7 +51,7 @@ func (c *client) GetEndpointState() (*api.AzureCNIState, error) {
 }
 
 func (c *client) GetVersion() (*semver.Version, error) {
-	cmd := c.exec.Command(azureVnetExecutable, "-v")
+	cmd := c.exec.Command(platform.CNIBinaryPath, "-v")
 
 	output, err := cmd.CombinedOutput()
 	if err != nil {

cns/cnireconciler/statefile.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	"github.com/Azure/azure-container-networking/cns/logger"
+	"github.com/Azure/azure-container-networking/platform"
 )
 
 // WriteObjectToCNIStatefile checks for a file at the CNI statefile path,
@@ -18,7 +19,7 @@ import (
 // empty file on the host filesystem, crashing older CNI because it doesn't know
 // how to handle empty statefiles.
 func WriteObjectToCNIStatefile() error {
-	filename := "/var/run/azure-vnet.json"
+	filename := platform.CNIStateFilePath
 	return writeObjectToFile(filename)
 }
 

cns/configuration/configuration.go

@@ -66,7 +66,12 @@ type ManagedSettings struct {
 	NodeSyncIntervalInSeconds int
 }
 
-func getConfigFilePath() (string, error) {
+func getConfigFilePath(cmdLineConfigPath string) (string, error) {
+	// If config path is set from cmd line, return that
+	if cmdLineConfigPath != "" {
+		return cmdLineConfigPath, nil
+	}
+
 	// Check if env set for config path otherwise use default path
 	configpath, found := os.LookupEnv(EnvCNSConfig)
 	if !found {
@@ -80,8 +85,8 @@ func getConfigFilePath() (string, error) {
 }
 
 // ReadConfig returns a CNS config from file or an error.
-func ReadConfig() (*CNSConfig, error) {
-	configpath, err := getConfigFilePath()
+func ReadConfig(cmdLineConfigPath string) (*CNSConfig, error) {
+	configpath, err := getConfigFilePath(cmdLineConfigPath)
 	if err != nil {
 		return nil, err
 	}

cns/configuration/configuration_test.go

@@ -14,15 +14,20 @@ func TestGetConfigFilePath(t *testing.T) {
 	execpath, _ := common.GetExecutableDirectory()
 
 	// env unset
-	f, err := getConfigFilePath()
+	f, err := getConfigFilePath("")
 	assert.NoError(t, err)
 	assert.Equal(t, filepath.Join(execpath, defaultConfigName), f)
 
 	// env set
 	os.Setenv(EnvCNSConfig, "test.cfg")
-	f, err = getConfigFilePath()
+	f, err = getConfigFilePath("")
 	assert.NoError(t, err)
 	assert.Equal(t, "test.cfg", f)
+
+	// test with cmdline config path
+	f, err = getConfigFilePath("/var/lib/cns_config.json")
+	assert.NoError(t, err)
+	assert.Equal(t, "/var/lib/cns_config.json", f)
 }
 
 func TestReadConfigFromFile(t *testing.T) {

cns/restserver/util.go

@@ -454,6 +454,11 @@ func (service *HTTPRestService) restoreNetworkState() error {
 		return nil
 	}
 
+	if !service.store.Exists() {
+		logger.Printf("[Azure CNS] Store does not exist, nothing to restore for network state.")
+		return nil
+	}
+
 	rebooted := false
 	modTime, err := service.store.GetModificationTime()
 

cns/service/main.go

@@ -251,6 +251,13 @@ var args = acn.ArgumentList{
 		Type:         "string",
 		DefaultValue: "",
 	},
+	{
+		Name:         acn.OptCNSConfigPath,
+		Shorthand:    acn.OptCNSConfigPathAlias,
+		Description:  "Path to cns config file",
+		Type:         "string",
+		DefaultValue: "",
+	},
 }
 
 // init() is executed before main() whenever this package is imported
@@ -385,6 +392,7 @@ func main() {
 	nodeID := acn.GetArg(acn.OptNodeID).(string)
 	clientDebugCmd := acn.GetArg(acn.OptDebugCmd).(string)
 	clientDebugArg := acn.GetArg(acn.OptDebugArg).(string)
+	cmdLineConfigPath := acn.GetArg(acn.OptCNSConfigPath).(string)
 
 	if vers {
 		printVersion()
@@ -418,7 +426,8 @@ func main() {
 		logger.Errorf("[Azure CNS] Cannot disable telemetry via cmdline. Update cns_config.json to disable telemetry.")
 	}
 
-	cnsconfig, err := configuration.ReadConfig()
+	logger.Printf("[Azure CNS] cmdLineConfigPath: %s", cmdLineConfigPath)
+	cnsconfig, err := configuration.ReadConfig(cmdLineConfigPath)
 	if err != nil {
 		logger.Errorf("[Azure CNS] Error reading cns config: %v", err)
 	}

common/config.go

@@ -122,4 +122,8 @@ const (
 	// Client mode, args for cmd
 	OptDebugArg      = "debugarg"
 	OptDebugArgAlias = "darg"
+
+	// CNS config path
+	OptCNSConfigPath      = "config-path"
+	OptCNSConfigPathAlias = "cp"
 )

platform/os_linux.go

@@ -21,6 +21,10 @@ const (
 	CNIRuntimePath = "/var/run/"
 	// CNILockPath is the path where CNI lock files are stored.
 	CNILockPath = "/var/run/azure-vnet/"
+	// CNIStateFilePath is the path to the CNI state file
+	CNIStateFilePath = "/var/run/azure-vnet.json"
+	// CNIBinaryPath is the path to the CNI binary
+	CNIBinaryPath = "/opt/cni/bin/azure-vnet"
 	// CNSRuntimePath is the path where CNS state files are stored.
 	CNSRuntimePath = "/var/run/"
 	// CNI runtime path on a Kubernetes cluster

platform/os_windows.go

@@ -26,6 +26,12 @@ const (
 	// CNILockPath is the path where CNI lock files are stored.
 	CNILockPath = ""
 
+	// CNIStateFilePath is the path to the CNI state file
+	CNIStateFilePath = "C:\\k\\azure-vnet.json"
+
+	// CNIBinaryPath is the path to the CNI binary
+	CNIBinaryPath = "C:\\k\\azurecni\\bin\\azure-vnet.exe"
+
 	// CNI runtime path on a Kubernetes cluster
 	K8SCNIRuntimePath = "C:\\k\\azurecni\\bin"
 

store/json.go

@@ -54,6 +54,13 @@ func NewJsonFileStore(fileName string, lockclient processlock.Interface) (KeyVal
 	return kvs, nil
 }
 
+func (kvs *jsonFileStore) Exists() bool {
+	if _, err := os.Stat(kvs.fileName); err != nil {
+		return false
+	}
+	return true
+}
+
 // Read restores the value for the given key from persistent store.
 func (kvs *jsonFileStore) Read(key string, value interface{}) error {
 	kvs.Mutex.Lock()

store/mockstore.go

@@ -15,6 +15,10 @@ func NewMockStore(lockFilePath string) KeyValueStore {
 	}
 }
 
+func (ms *mockStore) Exists() bool {
+	return false
+}
+
 // Read restores the value for the given key from persistent store.
 func (ms *mockStore) Read(key string, value interface{}) error {
 	return nil

store/store.go

@@ -10,6 +10,7 @@ import (
 
 // KeyValueStore represents a persistent store of (key,value) pairs.
 type KeyValueStore interface {
+	Exists() bool
 	Read(key string, value interface{}) error
 	Write(key string, value interface{}) error
 	Flush() error

testutils/store_mock.go

@@ -12,6 +12,7 @@ import (
 var _ store.KeyValueStore = (*KeyValueStoreMock)(nil)
 
 type KeyValueStoreMock struct {
+	ExistsBool               bool
 	ReadError                error
 	WriteError               error
 	FlushError               error
@@ -21,6 +22,10 @@ type KeyValueStoreMock struct {
 	GetModificationTimeError error
 }
 
+func (mockst *KeyValueStoreMock) Exists() bool {
+	return mockst.ExistsBool
+}
+
 func (mockst *KeyValueStoreMock) Read(key string, value interface{}) error {
 	return mockst.ReadError
 }