Update Agent to support backpressure from server

docs/proto/proto.md

@@ -12,6 +12,8 @@
     - [AgentDetails](#f5-nginx-agent-sdk-AgentDetails)
     - [AgentLogging](#f5-nginx-agent-sdk-AgentLogging)
     - [AgentMeta](#f5-nginx-agent-sdk-AgentMeta)
+    - [Backoff](#f5-nginx-agent-sdk-Backoff)
+    - [Server](#f5-nginx-agent-sdk-Server)
 
     - [AgentConnectStatus.StatusCode](#f5-nginx-agent-sdk-AgentConnectStatus-StatusCode)
     - [AgentLogging.Level](#f5-nginx-agent-sdk-AgentLogging-Level)
@@ -204,6 +206,7 @@ Represents agent details. This message is sent from the management server to the
 | extensions | [string](#string) | repeated | List of agent extensions that are enabled |
 | tags | [string](#string) | repeated | List of tags |
 | alias | [string](#string) |  | Alias name for the agent |
+| server | [Server](#f5-nginx-agent-sdk-Server) |  | Server setting for the agent |
 
 
 
@@ -251,6 +254,45 @@ Represents agent metadata
 
 
 
+
+<a name="f5-nginx-agent-sdk-Backoff"></a>
+
+### Backoff
+
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| initial_interval | [int64](#int64) |  | First backoff time interval in seconds |
+| randomization_factor | [double](#double) |  | Random value used to create range around next backoff interval |
+| multiplier | [double](#double) |  | Value to be multiplied with current backoff interval |
+| max_interval | [int64](#int64) |  | Max interval in seconds between two retries |
+| max_elapsed_time | [int64](#int64) |  | Elapsed time in seconds after which backoff stops. It never stops if max_elapsed_time == 0. |
+
+
+
+
+
+
+<a name="f5-nginx-agent-sdk-Server"></a>
+
+### Server
+
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| host | [string](#string) |  | Host name or IP of the host to connect to |
+| grpc_port | [int32](#int32) |  | Grpc port to connect to |
+| token | [string](#string) |  | Shared secrect between the server and client |
+| metrics | [string](#string) |  | Metrics server name |
+| command | [string](#string) |  | Command server name |
+| backoff | [Backoff](#f5-nginx-agent-sdk-Backoff) |  | Backoff settings for exponential retry and backoff |
+
+
+
+
+
 
 
 

go.mod

@@ -39,7 +39,7 @@ require (
 
 require (
 	github.com/bufbuild/buf v1.17.0
-	github.com/evilmartians/lefthook v1.3.10
+	github.com/evilmartians/lefthook v1.3.12
 	github.com/go-resty/resty/v2 v2.7.0
 	github.com/go-swagger/go-swagger v0.30.4
 	github.com/goreleaser/nfpm/v2 v2.28.0

go.sum

@@ -149,8 +149,8 @@ github.com/envoyproxy/go-control-plane v0.9.9-0.20201210154907-fd9021fe5dad/go.m
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/envoyproxy/protoc-gen-validate v0.3.0-java h1:bV5JGEB1ouEzZa0hgVDFFiClrUEuGWRaAc/3mxR2QK0=
 github.com/envoyproxy/protoc-gen-validate v0.3.0-java/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
-github.com/evilmartians/lefthook v1.3.10 h1:tGnI6JAW74/ZLXIESrdLjWQpPJEfjRmfzY90W3r+rHU=
-github.com/evilmartians/lefthook v1.3.10/go.mod h1:Ybinyhjf5wdloc78pkBV2K0XZRvdnsIova48LAco5HU=
+github.com/evilmartians/lefthook v1.3.12 h1:06BAk0p3pJ8TMnVl9gjPVPAPWWXJbREryvmwi4FfBfo=
+github.com/evilmartians/lefthook v1.3.12/go.mod h1:Ybinyhjf5wdloc78pkBV2K0XZRvdnsIova48LAco5HU=
 github.com/fatih/color v1.14.1 h1:qfhVLaG5s+nCROl1zJsZRxFeYrHLqWroPOQ8BWiNb4w=
 github.com/fatih/color v1.14.1/go.mod h1:2oHN61fhTpgcxD3TSWCgKDiH1+x4OiDVVGH8WlgGZGg=
 github.com/felixge/fgprof v0.9.3 h1:VvyZxILNuCiUCSXtPtYmmtGvb65nqXh2QFWc0Wpf2/g=

sdk/backoff.go → sdk/backoff/backoff.go

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package sdk
+package backoff
 
 import (
 	"context"
@@ -19,19 +19,25 @@ const (
 	BACKOFF_MULTIPLIER = backoff.DefaultMultiplier
 )
 
+type BackoffSettings struct {
+	InitialInterval time.Duration
+	MaxInterval     time.Duration
+	MaxElapsedTime  time.Duration
+	Multiplier      float64
+	Jitter          float64
+}
+
 func WaitUntil(
 	ctx context.Context,
-	initialInterval time.Duration,
-	maxInterval time.Duration,
-	maxElapsedTime time.Duration,
+	backoffSettings BackoffSettings,
 	operation backoff.Operation,
 ) error {
 	exponentialBackoff := backoff.NewExponentialBackOff()
-	exponentialBackoff.InitialInterval = initialInterval
-	exponentialBackoff.MaxInterval = maxInterval
-	exponentialBackoff.MaxElapsedTime = maxElapsedTime
-	exponentialBackoff.RandomizationFactor = BACKOFF_JITTER
-	exponentialBackoff.Multiplier = BACKOFF_MULTIPLIER
+	exponentialBackoff.InitialInterval = backoffSettings.InitialInterval
+	exponentialBackoff.MaxInterval = backoffSettings.MaxInterval
+	exponentialBackoff.MaxElapsedTime = backoffSettings.MaxElapsedTime
+	exponentialBackoff.RandomizationFactor = backoffSettings.Jitter
+	exponentialBackoff.Multiplier = backoffSettings.Multiplier
 
 	expoBackoffWithContext := backoff.WithContext(exponentialBackoff, ctx)
 

sdk/backoff_test.go → sdk/backoff/backoff_test.go

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package sdk
+package backoff
 
 import (
 	"context"
@@ -87,7 +87,14 @@ func TestBackOff(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		result := WaitUntil(test.context, test.initialInterval, test.maxInterval, test.maxElapsedTime, test.operation)
+		backoff := BackoffSettings{
+			InitialInterval: test.initialInterval,
+			MaxInterval:     test.maxInterval,
+			MaxElapsedTime:  test.maxElapsedTime,
+			Jitter:          BACKOFF_JITTER,
+			Multiplier:      BACKOFF_MULTIPLIER,
+		}
+		result := WaitUntil(test.context, backoff, test.operation)
 
 		if test.expectedError {
 			assert.Errorf(t, result, test.name)

sdk/client/client.go

@@ -15,17 +15,11 @@ import (
 
 	"google.golang.org/grpc"
 
+	"github.com/nginx/agent/sdk/v2/backoff"
 	"github.com/nginx/agent/sdk/v2/interceptors"
 	"github.com/nginx/agent/sdk/v2/proto"
 )
 
-type BackoffSettings struct {
-	initialInterval time.Duration
-	maxInterval     time.Duration
-	maxTimeout      time.Duration
-	sendMaxTimeout  time.Duration
-}
-
 type MsgClassification int
 
 const (
@@ -35,11 +29,12 @@ const (
 )
 
 var (
-	DefaultBackoffSettings = BackoffSettings{
-		initialInterval: 10 * time.Second,
-		maxInterval:     60 * time.Second,
-		maxTimeout:      0,
-		sendMaxTimeout:  2 * time.Minute,
+	DefaultBackoffSettings = backoff.BackoffSettings{
+		InitialInterval: 10 * time.Second,
+		MaxInterval:     60 * time.Second,
+		MaxElapsedTime:  2 * time.Minute,
+		Jitter:          backoff.BACKOFF_JITTER,
+		Multiplier:      backoff.BACKOFF_MULTIPLIER,
 	}
 )
 
@@ -68,7 +63,7 @@ type (
 		WithInterceptor(interceptor interceptors.Interceptor) Client
 		WithClientInterceptor(interceptor interceptors.ClientInterceptor) Client
 
-		WithBackoffSettings(backoffSettings BackoffSettings) Client
+		WithBackoffSettings(backoffSettings backoff.BackoffSettings) Client
 	}
 	MetricReporter interface {
 		Client

sdk/client/commander.go

@@ -19,7 +19,7 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/status"
 
-	"github.com/nginx/agent/sdk/v2"
+	"github.com/nginx/agent/sdk/v2/backoff"
 	"github.com/nginx/agent/sdk/v2/checksum"
 	sdkGRPC "github.com/nginx/agent/sdk/v2/grpc"
 	"github.com/nginx/agent/sdk/v2/interceptors"
@@ -49,7 +49,7 @@ type commander struct {
 	downloadChan    chan *proto.DataChunk
 	ctx             context.Context
 	mu              sync.Mutex
-	backoffSettings BackoffSettings
+	backoffSettings backoff.BackoffSettings
 }
 
 func (c *commander) WithInterceptor(interceptor interceptors.Interceptor) Client {
@@ -71,11 +71,9 @@ func (c *commander) Connect(ctx context.Context) error {
 	log.Debugf("Commander connecting to %s", c.server)
 
 	c.ctx = ctx
-	err := sdk.WaitUntil(
+	err := backoff.WaitUntil(
 		c.ctx,
-		c.backoffSettings.initialInterval,
-		c.backoffSettings.maxInterval,
-		c.backoffSettings.maxTimeout,
+		c.backoffSettings,
 		c.createClient,
 	)
 	if err != nil {
@@ -122,7 +120,7 @@ func (c *commander) ChunksSize() int {
 	return c.chunkSize
 }
 
-func (c *commander) WithBackoffSettings(backoffSettings BackoffSettings) Client {
+func (c *commander) WithBackoffSettings(backoffSettings backoff.BackoffSettings) Client {
 	c.backoffSettings = backoffSettings
 	return c
 }
@@ -136,13 +134,13 @@ func (c *commander) Send(ctx context.Context, message Message) error {
 	switch message.Classification() {
 	case MsgClassificationCommand:
 		if cmd, ok = message.Raw().(*proto.Command); !ok {
-			return fmt.Errorf("Expected a command message, but received %T", message.Data())
+			return fmt.Errorf("expected a command message, but received %T", message.Data())
 		}
 	default:
-		return fmt.Errorf("Expected a command message, but received %T", message.Data())
+		return fmt.Errorf("expected a command message, but received %T", message.Data())
 	}
 
-	err := sdk.WaitUntil(c.ctx, c.backoffSettings.initialInterval, c.backoffSettings.maxInterval, c.backoffSettings.sendMaxTimeout, func() error {
+	err := backoff.WaitUntil(c.ctx, c.backoffSettings, func() error {
 		if err := c.channel.Send(cmd); err != nil {
 			return c.handleGrpcError("Commander Channel Send", err)
 		}
@@ -163,7 +161,7 @@ func (c *commander) Download(ctx context.Context, metadata *proto.Metadata) (*pr
 	log.Debugf("Downloading config (messageId=%s)", metadata.GetMessageId())
 	cfg := &proto.NginxConfig{}
 
-	err := sdk.WaitUntil(c.ctx, c.backoffSettings.initialInterval, c.backoffSettings.maxInterval, c.backoffSettings.sendMaxTimeout, func() error {
+	err := backoff.WaitUntil(c.ctx, c.backoffSettings, func() error {
 		var (
 			header *proto.DataChunk_Header
 			body   []byte
@@ -228,7 +226,7 @@ func (c *commander) Upload(ctx context.Context, cfg *proto.NginxConfig, messageI
 	payloadChecksum := checksum.Checksum(payload)
 	chunks := checksum.Chunk(payload, c.chunkSize)
 
-	return sdk.WaitUntil(c.ctx, c.backoffSettings.initialInterval, c.backoffSettings.maxInterval, c.backoffSettings.sendMaxTimeout, func() error {
+	return backoff.WaitUntil(c.ctx, c.backoffSettings, func() error {
 		sender, err := c.client.Upload(c.ctx)
 		if err != nil {
 			return c.handleGrpcError("Commander Upload", err)
@@ -314,7 +312,7 @@ func (c *commander) createClient() error {
 func (c *commander) recvLoop() {
 	log.Debug("Commander receive loop starting")
 	for {
-		err := sdk.WaitUntil(c.ctx, c.backoffSettings.initialInterval, c.backoffSettings.maxInterval, c.backoffSettings.maxTimeout, func() error {
+		err := backoff.WaitUntil(c.ctx, c.backoffSettings, func() error {
 			cmd, err := c.channel.Recv()
 			log.Infof("Commander received %v, %v", cmd, err)
 			if err != nil {

sdk/client/commander_mock_test.go

@@ -11,6 +11,7 @@ import (
 	"context"
 	"time"
 
+	"github.com/nginx/agent/sdk/v2/backoff"
 	"github.com/nginx/agent/sdk/v2/interceptors"
 	"github.com/nginx/agent/sdk/v2/proto"
 	"github.com/stretchr/testify/mock"
@@ -93,7 +94,7 @@ func (m *MockCommandClient) WithConnWaitDuration(d time.Duration) Client {
 	return m
 }
 
-func (m *MockCommandClient) WithBackoffSettings(backoffSettings BackoffSettings) Client {
+func (m *MockCommandClient) WithBackoffSettings(backoffSettings backoff.BackoffSettings) Client {
 	m.Called(backoffSettings)
 
 	return m