feat(464): add support for queueing async actions in background (#544)

* feat(464): add support for queueing async actions in background
* Tidy deps
* Fix bug in using goroutines for running async actions
* Add log message to see if Redis is enabled for publishing async tasks
* Add default values for the config options

---------

Co-authored-by: Mostafa Moradian <mostafa@gatewayd.io>

Author: Hamsajj

.golangci.yaml

@@ -74,6 +74,7 @@ linters-settings:
           - "golang.org/x/text/cases"
           - "golang.org/x/text/language"
           - "gopkg.in/yaml.v2"
+          - "github.com/redis/go-redis/v9"
       test:
         files:
           - $test
@@ -92,6 +93,8 @@ linters-settings:
           - "github.com/knadh/koanf"
           - "github.com/spf13/cast"
           - "github.com/jackc/pgx/v5/pgproto3"
+          - "github.com/testcontainers/testcontainers-go"
+          - "github.com/redis/go-redis/v9"
   tagalign:
     align: false
     sort: false

act/act_helpers_test.go

@@ -1,9 +1,14 @@
 package act
 
 import (
+	"context"
+	"testing"
 	"time"
 
 	sdkAct "github.com/gatewayd-io/gatewayd-plugin-sdk/act"
+	"github.com/stretchr/testify/assert"
+	"github.com/testcontainers/testcontainers-go"
+	"github.com/testcontainers/testcontainers-go/modules/redis"
 )
 
 func createWaitActEntities(async bool) (
@@ -49,3 +54,20 @@ func createWaitActEntities(async bool) (
 
 	return name, actions, signals, policy
 }
+
+func createTestRedis(t *testing.T) string {
+	t.Helper()
+	ctx := context.Background()
+
+	redisContainer, err := redis.RunContainer(ctx, testcontainers.WithImage("redis:6"))
+
+	assert.NoError(t, err)
+	t.Cleanup(func() {
+		assert.NoError(t, redisContainer.Terminate(ctx))
+	})
+	host, err := redisContainer.Host(ctx)
+	assert.NoError(t, err)
+	port, err := redisContainer.MappedPort(ctx, "6379/tcp")
+	assert.NoError(t, err)
+	return host + ":" + port.Port()
+}

act/publisher.go

@@ -0,0 +1,40 @@
+package act
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/redis/go-redis/v9"
+	"github.com/rs/zerolog"
+)
+
+type IPublisher interface {
+	Publish(ctx context.Context, payload []byte) error
+}
+
+var _ IPublisher = (*Publisher)(nil)
+
+type Publisher struct {
+	Logger      zerolog.Logger
+	RedisDB     redis.Cmdable
+	ChannelName string
+}
+
+func NewPublisher(publisher Publisher) (*Publisher, error) {
+	if err := publisher.RedisDB.Ping(context.Background()).Err(); err != nil {
+		publisher.Logger.Err(err).Msg("failed to connect redis")
+	}
+	return &Publisher{
+		Logger:      publisher.Logger,
+		RedisDB:     publisher.RedisDB,
+		ChannelName: publisher.ChannelName,
+	}, nil
+}
+
+func (p *Publisher) Publish(ctx context.Context, payload []byte) error {
+	if err := p.RedisDB.Publish(ctx, p.ChannelName, payload).Err(); err != nil {
+		p.Logger.Err(err).Str("ChannelName", p.ChannelName).Msg("failed to publish task to redis")
+		return fmt.Errorf("failed to publish task to redis: %w", err)
+	}
+	return nil
+}

act/registry.go

@@ -2,7 +2,9 @@ package act
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
+	"fmt"
 	"slices"
 	"time"
 
@@ -26,6 +28,10 @@ type Registry struct {
 	// Default timeout for running actions
 	DefaultActionTimeout time.Duration
 
+	// TaskPublisher is the publisher for async actions.
+	// if not given, will invoke simple goroutine to run async actions
+	TaskPublisher *Publisher
+
 	Signals           map[string]*sdkAct.Signal
 	Policies          map[string]*sdkAct.Policy
 	Actions           map[string]*sdkAct.Action
@@ -34,6 +40,27 @@ type Registry struct {
 	DefaultSignal     *sdkAct.Signal
 }
 
+type AsyncActionMessage struct {
+	Output *sdkAct.Output
+	Params []sdkAct.Parameter
+}
+
+// Encode marshals the AsyncActionMessage struct to JSON bytes.
+func (msg *AsyncActionMessage) Encode() ([]byte, error) {
+	marshaled, err := json.Marshal(msg)
+	if err != nil {
+		return nil, fmt.Errorf("error encoding JSON: %w", err)
+	}
+	return marshaled, nil
+}
+
+func (msg *AsyncActionMessage) Decode(data []byte) error {
+	if err := json.Unmarshal(data, msg); err != nil {
+		return fmt.Errorf("error decoding JSON: %w", err)
+	}
+	return nil
+}
+
 var _ IRegistry = (*Registry)(nil)
 
 // NewActRegistry creates a new act registry with the specified default policy and timeout
@@ -88,6 +115,7 @@ func NewActRegistry(
 		Actions:              registry.Actions,
 		DefaultPolicy:        registry.Policies[registry.DefaultPolicyName],
 		DefaultSignal:        registry.Signals[registry.DefaultPolicyName],
+		TaskPublisher:        registry.TaskPublisher,
 	}
 }
 
@@ -234,6 +262,18 @@ func (r *Registry) Run(
 	if action.Timeout > 0 {
 		timeout = time.Duration(action.Timeout) * time.Second
 	}
+
+	// if task is async and publisher is configured, publish it and do not run it
+	if r.TaskPublisher != nil && !action.Sync {
+		err := r.publishTask(output, params)
+		if err != nil {
+			r.Logger.Error().Err(err).Msg("Error publishing async action")
+			return nil, gerr.ErrPublishingAsyncAction
+		}
+		return nil, gerr.ErrAsyncAction
+	}
+
+	// no publisher, or sync action. run the action
 	var ctx context.Context
 	var cancel context.CancelFunc
 	// if timeout is zero, then the context should not have timeout
@@ -248,14 +288,83 @@ func (r *Registry) Run(
 		return runActionWithTimeout(ctx, action, output, params, r.Logger)
 	}
 
-	// Run the action asynchronously.
+	// If the action is asynchronous, run it in a goroutine and return the sentinel error.
 	go func() {
 		defer cancel()
 		_, _ = runActionWithTimeout(ctx, action, output, params, r.Logger)
 	}()
+
 	return nil, gerr.ErrAsyncAction
 }
 
+func (r *Registry) publishTask(output *sdkAct.Output, params []sdkAct.Parameter) error {
+	r.Logger.Debug().Msg("Publishing async action")
+	task := AsyncActionMessage{
+		Output: output,
+		Params: params,
+	}
+	payload, err := task.Encode()
+	if err != nil {
+		return err
+	}
+	if err := r.TaskPublisher.Publish(context.Background(), payload); err != nil {
+		return fmt.Errorf("error publishing task: %w", err)
+	}
+	return nil
+}
+
+func (r *Registry) runAsyncActionFn(ctx context.Context, message []byte) error {
+	msg := &AsyncActionMessage{}
+	if err := msg.Decode(message); err != nil {
+		r.Logger.Error().Err(err).Msg("Error decoding message")
+		return err
+	}
+	output := msg.Output
+	params := msg.Params
+
+	// In certain cases, the output may be nil, for example, if the policy
+	// evaluation fails. In this case, the run is aborted.
+	if output == nil {
+		// This should never happen, since the output is always set by the registry
+		// to be the default policy if no signals are provided.
+		r.Logger.Debug().Msg("Output is nil, run aborted")
+		return gerr.ErrNilPointer
+	}
+
+	action, ok := r.Actions[output.MatchedPolicy]
+	if !ok {
+		r.Logger.Warn().Str("matchedPolicy", output.MatchedPolicy).Msg(
+			"Action does not exist, run aborted")
+		return gerr.ErrActionNotExist
+	}
+
+	// Prepend the logger to the parameters if needed.
+	if len(params) == 0 || params[0].Key != LoggerKey {
+		params = append([]sdkAct.Parameter{WithLogger(r.Logger)}, params...)
+	} else {
+		params[0] = WithLogger(r.Logger)
+	}
+
+	timeout := r.DefaultActionTimeout
+	if action.Timeout > 0 {
+		timeout = time.Duration(action.Timeout) * time.Second
+	}
+	var ctxWithTimeout context.Context
+	var cancel context.CancelFunc
+	// if timeout is zero, then the context should not have timeout
+	if timeout > 0 {
+		ctxWithTimeout, cancel = context.WithTimeout(ctx, timeout)
+	} else {
+		ctxWithTimeout, cancel = context.WithCancel(ctx)
+	}
+	// If the action is synchronous, run it and return the result immediately.
+	defer cancel()
+	if _, err := runActionWithTimeout(ctxWithTimeout, action, output, params, r.Logger); err != nil {
+		return err
+	}
+	return nil
+}
+
 func runActionWithTimeout(
 	ctx context.Context,
 	action *sdkAct.Action,
@@ -293,7 +402,7 @@ func runActionWithTimeout(
 	}
 }
 
-// WithLogger returns a parameter with the logger to be used by the action.
+// WithLogger returns a parameter with the Logger to be used by the action.
 // This is automatically prepended to the parameters when running an action.
 func WithLogger(logger zerolog.Logger) sdkAct.Parameter {
 	return sdkAct.Parameter{

act/registry_test.go

@@ -2,12 +2,16 @@ package act
 
 import (
 	"bytes"
+	"context"
+	"sync"
 	"testing"
 	"time"
 
 	sdkAct "github.com/gatewayd-io/gatewayd-plugin-sdk/act"
 	"github.com/gatewayd-io/gatewayd/config"
 	gerr "github.com/gatewayd-io/gatewayd/errors"
+	"github.com/hashicorp/go-hclog"
+	"github.com/redis/go-redis/v9"
 	"github.com/rs/zerolog"
 	"github.com/spf13/cast"
 	"github.com/stretchr/testify/assert"
@@ -705,6 +709,88 @@ func Test_Run_Async(t *testing.T) {
 	assert.Contains(t, out.String(), "{\"level\":\"info\",\"async\":true,\"message\":\"test\"}")
 }
 
+// Test_Run_Async tests the Run function of the act registry with an asynchronous action.
+func Test_Run_Async_Redis(t *testing.T) {
+	out := bytes.Buffer{}
+	logger := zerolog.New(&out)
+	hclogger := hclog.New(&hclog.LoggerOptions{
+		Output:     &out,
+		Level:      hclog.Debug,
+		JSONFormat: true,
+	})
+
+	rdbAddr := createTestRedis(t)
+	rdb := redis.NewClient(&redis.Options{
+		Addr: rdbAddr,
+	})
+	publisher, err := NewPublisher(Publisher{
+		Logger:      logger,
+		RedisDB:     rdb,
+		ChannelName: "test-async-chan",
+	})
+	require.NoError(t, err)
+
+	var waitGroup sync.WaitGroup
+	actRegistry := NewActRegistry(
+		Registry{
+			Signals:              BuiltinSignals(),
+			Policies:             BuiltinPolicies(),
+			Actions:              BuiltinActions(),
+			DefaultPolicyName:    config.DefaultPolicy,
+			PolicyTimeout:        config.DefaultPolicyTimeout,
+			DefaultActionTimeout: config.DefaultActionTimeout,
+			Logger:               logger,
+			TaskPublisher:        publisher,
+		})
+	assert.NotNil(t, actRegistry)
+
+	consumer, err := sdkAct.NewConsumer(hclogger, rdb, 5, "test-async-chan")
+	require.NoError(t, err)
+
+	require.NoError(t, consumer.Subscribe(context.Background(), func(ctx context.Context, task []byte) error {
+		err := actRegistry.runAsyncActionFn(ctx, task)
+		waitGroup.Done()
+		return err
+	}))
+
+	outputs := actRegistry.Apply([]sdkAct.Signal{
+		*sdkAct.Log("info", "test", map[string]any{"async": true}),
+	}, sdkAct.Hook{
+		Name:     "HOOK_NAME_ON_TRAFFIC_FROM_CLIENT",
+		Priority: 1000,
+		Params:   map[string]any{},
+		Result:   map[string]any{},
+	})
+	assert.NotNil(t, outputs)
+	assert.Equal(t, "log", outputs[0].MatchedPolicy)
+	assert.Equal(t,
+		map[string]interface{}{
+			"async":   true,
+			"level":   "info",
+			"log":     true,
+			"message": "test",
+		},
+		outputs[0].Metadata,
+	)
+	assert.False(t, outputs[0].Sync)
+	assert.True(t, cast.ToBool(outputs[0].Verdict))
+	assert.False(t, outputs[0].Terminal)
+	waitGroup.Add(1)
+	result, err := actRegistry.Run(outputs[0], WithResult(map[string]any{"key": "value"}))
+	waitGroup.Wait()
+	assert.Equal(t, err, gerr.ErrAsyncAction, "expected async action sentinel error")
+	assert.Nil(t, result, "expected nil result")
+
+	time.Sleep(time.Millisecond) // wait for async action to complete
+
+	// The following is the expected log output from running the async action.
+	assert.Contains(t, out.String(), "{\"level\":\"debug\",\"action\":\"log\",\"executionMode\":\"async\",\"message\":\"Running action\"}") //nolint:lll
+	// The following is the expected log output from the run function of the async action.
+	assert.Contains(t, out.String(), "{\"level\":\"info\",\"async\":true,\"message\":\"test\"}")
+	// The following is expected log from consumer in hclog format
+	assert.Contains(t, out.String(), "\"@level\":\"debug\",\"@message\":\"async redis task processed successfully\"")
+}
+
 // Test_Run_NilRegistry tests the Run function of the action with a nil output object.
 func Test_Run_NilOutput(t *testing.T) {
 	buf := bytes.Buffer{}