feat: Introduce Client as an interface

Refactor the Provider to depend on a Client interface instead of a concrete
implementation. This simplifies testing and mocking by allowing the Client
itself to be mocked, rather than individual gRPC calls.

Author: sven-rosenzweig

internal/provider/cisco/gnmiext/v2/client.go

@@ -55,21 +55,33 @@ type Capabilities struct {
 	SupportedModels []Model
 }
 
+type Client interface {
+	GetState(ctx context.Context, conf ...Configurable) error
+	GetConfig(ctx context.Context, conf ...Configurable) error
+	Patch(ctx context.Context, conf ...Configurable) error
+	Update(ctx context.Context, conf ...Configurable) error
+	Delete(ctx context.Context, conf ...Configurable) error
+}
+
 // Client is a gNMI client offering convenience methods for device configuration
 // using gNMI.
-type Client struct {
+type ClientObj struct {
 	gnmi         gpb.GNMIClient
 	encoding     gpb.Encoding
 	capabilities *Capabilities
 	logger       logr.Logger
 }
 
+var (
+	_ Client = &ClientObj{}
+)
+
 // New creates a new Client by negotiating capabilities with the gNMI server by
 // carrying out a Capabilities RPC.
 // Returns an error if the device doesn't support JSON encoding.
 // By default, the client uses [slog.Default] for logging.
 // Use [WithLogger] to provide a custom logger.
-func New(ctx context.Context, conn grpc.ClientConnInterface, opts ...Option) (*Client, error) {
+func New(ctx context.Context, conn grpc.ClientConnInterface, opts ...Option) (Client, error) {
 	gnmi := gpb.NewGNMIClient(conn)
 	res, err := gnmi.Capabilities(ctx, &gpb.CapabilityRequest{})
 	if err != nil {
@@ -96,18 +108,18 @@ func New(ctx context.Context, conn grpc.ClientConnInterface, opts ...Option) (*C
 		}
 	}
 	logger := logr.FromSlogHandler(slog.Default().Handler())
-	client := &Client{gnmi, encoding, capabilities, logger}
+	client := &ClientObj{gnmi, encoding, capabilities, logger}
 	for _, opt := range opts {
 		opt(client)
 	}
 	return client, nil
 }
 
-type Option func(*Client)
+type Option func(*ClientObj)
 
 // WithLogger sets a custom logger for the client.
 func WithLogger(logger logr.Logger) Option {
-	return func(c *Client) {
+	return func(c *ClientObj) {
 		c.logger = logger
 	}
 }
@@ -117,34 +129,34 @@ var ErrNil = errors.New("gnmiext: nil")
 
 // GetConfig retrieves config and unmarshals it into the provided targets.
 // If some of the values for the given xpaths are not defined, [ErrNil] is returned.
-func (c *Client) GetConfig(ctx context.Context, conf ...Configurable) error {
+func (c *ClientObj) GetConfig(ctx context.Context, conf ...Configurable) error {
 	return c.get(ctx, gpb.GetRequest_CONFIG, conf...)
 }
 
 // GetState retrieves state and unmarshals it into the provided targets.
 // If some of the values for the given xpaths are not defined, [ErrNil] is returned.
-func (c *Client) GetState(ctx context.Context, conf ...Configurable) error {
+func (c *ClientObj) GetState(ctx context.Context, conf ...Configurable) error {
 	return c.get(ctx, gpb.GetRequest_STATE, conf...)
 }
 
 // Update replaces the configuration for the given set of items.
 // If the current configuration equals the desired configuration, the operation is skipped.
 // For partial updates that merge changes, use [Client.Patch] instead.
-func (c *Client) Update(ctx context.Context, conf ...Configurable) error {
+func (c *ClientObj) Update(ctx context.Context, conf ...Configurable) error {
 	return c.set(ctx, false, conf...)
 }
 
 // Patch merges the configuration for the given set of items.
 // If the current configuration equals the desired configuration, the operation is skipped.
 // For full replacement of configuration, use [Client.Update] instead.
-func (c *Client) Patch(ctx context.Context, conf ...Configurable) error {
+func (c *ClientObj) Patch(ctx context.Context, conf ...Configurable) error {
 	return c.set(ctx, true, conf...)
 }
 
 // Delete resets the configuration for the given set of items.
 // If an item implements [Defaultable], it's reset to default value.
 // Otherwise, the configuration is deleted.
-func (c *Client) Delete(ctx context.Context, conf ...Configurable) error {
+func (c *ClientObj) Delete(ctx context.Context, conf ...Configurable) error {
 	if len(conf) == 0 {
 		return nil
 	}
@@ -179,7 +191,7 @@ func (c *Client) Delete(ctx context.Context, conf ...Configurable) error {
 // get retrieves data of the specified type (CONFIG or STATE) and unmarshals it
 // into the provided targets. If some of the values for the given xpaths are not
 // defined, [ErrNil] is returned.
-func (c *Client) get(ctx context.Context, dt gpb.GetRequest_DataType, conf ...Configurable) error {
+func (c *ClientObj) get(ctx context.Context, dt gpb.GetRequest_DataType, conf ...Configurable) error {
 	if len(conf) == 0 {
 		return nil
 	}
@@ -244,7 +256,7 @@ func (c *Client) get(ctx context.Context, dt gpb.GetRequest_DataType, conf ...Co
 // configuration. Otherwise, a full replacement is done.
 // If the current configuration equals the desired configuration, the operation
 // is skipped.
-func (c *Client) set(ctx context.Context, patch bool, conf ...Configurable) error {
+func (c *ClientObj) set(ctx context.Context, patch bool, conf ...Configurable) error {
 	if len(conf) == 0 {
 		return nil
 	}
@@ -293,7 +305,7 @@ func (c *Client) set(ctx context.Context, patch bool, conf ...Configurable) erro
 // Marshal marshals the provided value into a byte slice using the client's encoding.
 // If the value implements the [Marshaler] interface, it will be marshaled using that.
 // Otherwise, [json.Marshal] is used.
-func (c *Client) Marshal(v any) (b []byte, err error) {
+func (c *ClientObj) Marshal(v any) (b []byte, err error) {
 	if m, ok := v.(Marshaler); ok {
 		b, err = m.MarshalYANG(c.capabilities)
 		if err != nil {
@@ -311,7 +323,7 @@ func (c *Client) Marshal(v any) (b []byte, err error) {
 // Unmarshal unmarshals the provided byte slice into the provided destination.
 // If the destination implements the [Marshaler] interface, it will be unmarshaled using that.
 // Otherwise, [json.Unmarshal] is used.
-func (c *Client) Unmarshal(b []byte, dst any) (err error) {
+func (c *ClientObj) Unmarshal(b []byte, dst any) (err error) {
 	// NOTE: If you query for list elements on Cisco NX-OS, the encoded payload
 	// will be the wrapped in an array (even if only one element is requested), i.e.
 	//
@@ -339,7 +351,7 @@ func (c *Client) Unmarshal(b []byte, dst any) (err error) {
 }
 
 // Encode encodes the provided byte slice into a [gpb.TypedValue] using the client's encoding.
-func (c *Client) Encode(b []byte) *gpb.TypedValue {
+func (c *ClientObj) Encode(b []byte) *gpb.TypedValue {
 	switch c.encoding {
 	case gpb.Encoding_JSON:
 		return &gpb.TypedValue{
@@ -359,7 +371,7 @@ func (c *Client) Encode(b []byte) *gpb.TypedValue {
 }
 
 // Decode decodes the provided [gpb.TypedValue] into the provided destination using the client's encoding.
-func (c *Client) Decode(val *gpb.TypedValue) ([]byte, error) {
+func (c *ClientObj) Decode(val *gpb.TypedValue) ([]byte, error) {
 	switch c.encoding {
 	case gpb.Encoding_JSON:
 		v, ok := val.Value.(*gpb.TypedValue_JsonVal)

internal/provider/cisco/gnmiext/v2/client_test.go

@@ -502,7 +502,7 @@ func TestClient_GetConfig(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				encoding: gpb.Encoding_JSON,
 				gnmi:     gpb.NewGNMIClient(test.conn),
 			}
@@ -582,7 +582,7 @@ func TestClient_GetState(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				encoding: gpb.Encoding_JSON,
 				gnmi:     gpb.NewGNMIClient(test.conn),
 			}
@@ -853,7 +853,7 @@ func TestClient_Update(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				encoding: gpb.Encoding_JSON,
 				gnmi:     gpb.NewGNMIClient(test.conn),
 			}
@@ -1015,7 +1015,7 @@ func TestClient_Patch(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				encoding: gpb.Encoding_JSON_IETF,
 				gnmi:     gpb.NewGNMIClient(test.conn),
 			}
@@ -1133,7 +1133,7 @@ func TestClient_Delete(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				encoding: gpb.Encoding_JSON,
 				gnmi:     gpb.NewGNMIClient(test.conn),
 			}
@@ -1231,7 +1231,7 @@ func TestClient_Marshal(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				capabilities: &Capabilities{
 					SupportedModels: []Model{
 						{Name: "openconfig-interfaces", Organization: "OpenConfig working group", Version: "2.5.0"},
@@ -1288,7 +1288,7 @@ func TestClient_Unmarshal(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client := &Client{
+			client := &ClientObj{
 				capabilities: &Capabilities{
 					SupportedModels: []Model{
 						{Name: "openconfig-interfaces", Organization: "OpenConfig working group", Version: "2.5.0"},

internal/provider/cisco/iosxr/provider.go

@@ -0,0 +1,156 @@
+package iosxr
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/ironcore-dev/network-operator/internal/deviceutil"
+	"github.com/ironcore-dev/network-operator/internal/provider"
+	"github.com/ironcore-dev/network-operator/internal/provider/cisco/gnmiext/v2"
+	"google.golang.org/grpc"
+)
+
+var (
+	_ provider.Provider          = &Provider{}
+	_ provider.InterfaceProvider = &Provider{}
+)
+
+type Provider struct {
+	conn   *grpc.ClientConn
+	client gnmiext.Client
+}
+
+func NewProvider() provider.Provider {
+	return &Provider{}
+}
+
+func (p *Provider) Connect(ctx context.Context, conn *deviceutil.Connection) (err error) {
+	p.conn, err = deviceutil.NewGrpcClient(ctx, conn)
+	if err != nil {
+		return fmt.Errorf("failed to create grpc connection: %w", err)
+	}
+	p.client, err = gnmiext.New(ctx, p.conn)
+	if err != nil {
+		return err
+	}
+	fmt.Println("Connected to IOSXR device:", conn.Address)
+	return nil
+}
+
+func (p *Provider) Disconnect(ctx context.Context, conn *deviceutil.Connection) error {
+	return p.conn.Close()
+}
+
+func (p *Provider) EnsureInterface(ctx context.Context, req *provider.InterfaceRequest) error {
+	if p.client == nil {
+		return fmt.Errorf("client is not connected")
+	}
+	var name string = req.Interface.Spec.Name
+
+	var physif *PhisIf = NewIface(name)
+
+	physif.Name = req.Interface.Spec.Name
+	physif.Description = req.Interface.Spec.Description
+
+	physif.Statistics.LoadInterval = 30
+	owner, err := ExractMTUOwnerFromIfaceName(name)
+	if err != nil {
+		return fmt.Errorf("failed to extract MTU owner from interface name %s: %w", name, err)
+	}
+	physif.MTUs = MTUs{MTU: []MTU{{MTU: uint16(req.Interface.Spec.MTU), Owner: string(owner)}}}
+
+	// (fixme): for the moment it is enought to keep this static
+	// option1: extend existing interface spec
+	// option2: create a custom iosxr config
+	physif.Shutdown = Empty(false)
+	physif.Statistics.LoadInterval = uint8(30)
+
+	if len(req.Interface.Spec.IPv4.Addresses) == 0 {
+		return fmt.Errorf("no IPv4 address configured for interface %s", name)
+	}
+
+	if len(req.Interface.Spec.IPv4.Addresses) > 1 {
+		return fmt.Errorf("only a single primary IPv4 address is supported for interface %s", name)
+	}
+
+	// (fixme): support IPv6 addresses, IPv6 neighbor config
+	ip := req.Interface.Spec.IPv4.Addresses[0].Prefix.Addr().String()
+	ipNet := req.Interface.Spec.IPv4.Addresses[0].Prefix.Bits()
+	if err != nil {
+		return fmt.Errorf("failed to parse IPv4 address %s: %w", req.Interface.Spec.IPv4.Addresses[0], err)
+	}
+
+	physif.IPv4Network = IPv4Network{
+		Addresses: AddressesIPv4{
+			Primary: Primary{
+				Address: ip,
+				Netmask: string(ipNet),
+			},
+		},
+	}
+
+	// Check if interface exists otherwise patch will fail
+	var tmpiFace *PhisIf = NewIface(name)
+	err = p.client.GetConfig(ctx, tmpiFace)
+	if err != nil {
+		// Interface does not exist, create it
+		err = p.client.Update(ctx, physif)
+		if err != nil {
+			return fmt.Errorf("failed to create interface %s: %w", req.Interface.Spec.Name, err)
+		}
+		fmt.Printf("Interface %s created successfully\n", req.Interface.Spec.Name)
+		return nil
+	}
+
+	err = p.client.Patch(ctx, physif)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (p *Provider) DeleteInterface(ctx context.Context, req *provider.InterfaceRequest) error {
+	var iFace = NewIface(req.Interface.Spec.Name)
+
+	if p.client == nil {
+		return fmt.Errorf("client is not connected")
+	}
+
+	err := p.client.Delete(ctx, iFace)
+	if err != nil {
+		return fmt.Errorf("failed to delete interface %s: %w", req.Interface.Spec.Name, err)
+	}
+	return nil
+}
+
+func (p *Provider) GetInterfaceStatus(ctx context.Context, req *provider.InterfaceRequest) (provider.InterfaceStatus, error) {
+	state := new(PhysIfState)
+	state.Name = req.Interface.Spec.Name
+
+	if p.client == nil {
+		return provider.InterfaceStatus{}, fmt.Errorf("client is not connected")
+	}
+
+	states, err := p.client.GetStateWithMultipleUpdates(ctx, state)
+
+	if err != nil {
+		return provider.InterfaceStatus{}, fmt.Errorf("failed to get interface status for %s: %w", req.Interface.Spec.Name, err)
+	}
+
+	providerStatus := provider.InterfaceStatus{
+		OperStatus: true,
+	}
+	for _, s := range *states {
+		currState := s.(*PhysIfState)
+		if stateMapping[currState.State] != StateUp {
+			providerStatus.OperStatus = false
+			break
+		}
+	}
+	return providerStatus, nil
+}
+
+func init() {
+	provider.Register("cisco-iosxr-gnmi", NewProvider)
+}

internal/provider/cisco/nxos/intf.go

@@ -258,7 +258,7 @@ func Range(r []int32) string {
 }
 
 // Exists checks if all provided interface names exist on the device.
-func Exists(ctx context.Context, client *gnmiext.Client, names ...string) (bool, error) {
+func Exists(ctx context.Context, client gnmiext.Client, names ...string) (bool, error) {
 	if len(names) == 0 {
 		return false, errors.New("at least one interface name must be provided")
 	}

internal/provider/cisco/nxos/provider.go

@@ -47,7 +47,7 @@ var (
 
 type Provider struct {
 	conn   *grpc.ClientConn
-	client *gnmiext.Client
+	client gnmiext.Client
 }
 
 func NewProvider() provider.Provider {