add scaler for temporal

CHANGELOG.md

@@ -56,6 +56,8 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 
 ## Unreleased
 
+- ** General**: Introduce new Temporal scaler ([#4724](https://github.com/kedacore/keda/issues/4724))
+
 ### New
 
 - **General**: Enable OpenSSF Scorecard to enhance security practices across the project ([#5913](https://github.com/kedacore/keda/issues/5913))

go.mod

@@ -93,6 +93,7 @@ require (
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.31.0
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.31.0
 	go.opentelemetry.io/otel/metric v1.31.0
+	go.temporal.io/sdk v1.30.0
 	go.uber.org/mock v0.5.0
 	golang.org/x/oauth2 v0.23.0
 	golang.org/x/sync v0.8.0
@@ -212,6 +213,7 @@ require (
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/emicklei/go-restful/v3 v3.12.1 // indirect
 	github.com/evanphx/json-patch/v5 v5.9.0 // indirect
+	github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a // indirect
 	github.com/fatih/color v1.18.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
@@ -238,6 +240,7 @@ require (
 	github.com/golang-sql/civil v0.0.0-20220223132316-b832511892a9 // indirect
 	github.com/golang-sql/sqlexp v0.1.0 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/mock v1.6.0 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/cel-go v0.20.1 // indirect
@@ -299,14 +302,17 @@ require (
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
 	github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f // indirect
+	github.com/nexus-rpc/sdk-go v0.0.11 // indirect
 	github.com/oapi-codegen/runtime v1.1.1 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
+	github.com/pborman/uuid v1.2.1 // indirect
 	github.com/pierrec/lz4/v4 v4.1.21 // indirect
 	github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/prometheus/prometheus v0.49.0
 	github.com/rivo/uniseg v0.4.4 // indirect
+	github.com/robfig/cron v1.2.0 // indirect
 	github.com/ryanuber/go-glob v1.0.0 // indirect
 	github.com/samber/lo v1.39.0 // indirect
 	github.com/sergi/go-diff v1.2.0 // indirect
@@ -340,6 +346,7 @@ require (
 	go.opentelemetry.io/otel/sdk/metric v1.31.0
 	go.opentelemetry.io/otel/trace v1.31.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.3.1 // indirect
+	go.temporal.io/api v1.40.0 // indirect
 	go.uber.org/atomic v1.11.0
 	go.uber.org/automaxprocs v1.6.0
 	go.uber.org/multierr v1.11.0 // indirect

go.sum

@@ -1648,6 +1648,8 @@ github.com/evanphx/json-patch/v5 v5.9.0 h1:kcBlZQbplgElYIlo/n1hJbls2z/1awpXxpRi0
 github.com/evanphx/json-patch/v5 v5.9.0/go.mod h1:VNkHZ/282BpEyt/tObQO8s5CMPmYYq14uClGH4abBuQ=
 github.com/expr-lang/expr v1.16.9 h1:WUAzmR0JNI9JCiF0/ewwHB1gmcGw5wW7nWt8gc6PpCI=
 github.com/expr-lang/expr v1.16.9/go.mod h1:8/vRC7+7HBzESEqt5kKpYXxrxkr31SaO8r40VO/1IT4=
+github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a h1:yDWHCSQ40h88yih2JAcL6Ls/kVkSE8GFACTGVnMPruw=
+github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a/go.mod h1:7Ga40egUymuWXxAe151lTNnCv97MddSOVsjpPPkityA=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
 github.com/fatih/color v1.10.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGEBuJM=
@@ -1879,6 +1881,7 @@ github.com/google/s2a-go v0.1.8 h1:zZDs9gcbt9ZPLV0ndSyQk6Kacx2g/X+SKYovpnz3SMM=
 github.com/google/s2a-go v0.1.8/go.mod h1:6iNWHTpQ+nfNRN5E00MSdfDwVesa8hhS32PhPO8deJA=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
+github.com/google/uuid v1.0.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
@@ -2173,6 +2176,8 @@ github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86/go.mod h1:kHJE
 github.com/neelance/sourcemap v0.0.0-20200213170602-2833bce08e4c/go.mod h1:Qr6/a/Q4r9LP1IltGz7tA7iOK1WonHEYhu1HRBA7ZiM=
 github.com/newrelic/newrelic-client-go/v2 v2.51.2 h1:Xf+M0NuZuIuxqG48zYoqyIdQL514j2J1c+kNVYajcYI=
 github.com/newrelic/newrelic-client-go/v2 v2.51.2/go.mod h1:+RRjI3nDGWT3kLm9Oi3QxpBm70uu8q1upEHBVWCZFpo=
+github.com/nexus-rpc/sdk-go v0.0.11 h1:qH3Us3spfp50t5ca775V1va2eE6z1zMQDZY4mvbw0CI=
+github.com/nexus-rpc/sdk-go v0.0.11/go.mod h1:TpfkM2Cw0Rlk9drGkoiSMpFqflKTiQLWUNyKJjF8mKQ=
 github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
 github.com/nxadm/tail v1.4.8/go.mod h1:+ncqLTQzXmGhMZNUePPaPqPvBxHAIsmXswZKocGu+AU=
 github.com/oapi-codegen/runtime v1.1.1 h1:EXLHh0DXIJnWhdRPN2w4MXAzFyE4CskzhNLUmtpMYro=
@@ -2203,6 +2208,8 @@ github.com/otiai10/mint v1.3.0/go.mod h1:F5AjcsTsWUqX+Na9fpHb52P8pcRX2CI6A3ctIT9
 github.com/otiai10/mint v1.3.3/go.mod h1:/yxELlJQ0ufhjUwhshSj+wFjZ78CnZ48/1wtmBH1OTc=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pascaldekloe/goe v0.1.0/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
+github.com/pborman/uuid v1.2.1 h1:+ZZIw58t/ozdjRaXh/3awHfmWRbzYxJoAdNJxe/3pvw=
+github.com/pborman/uuid v1.2.1/go.mod h1:X/NO0urCmaxf9VXbdlT7C2Yzkj2IKimNn4k+gtPdI/k=
 github.com/pelletier/go-toml/v2 v2.2.2/go.mod h1:1t835xjRzz80PqgE6HHgN2JOsmgYu/h4qDAS4n929Rs=
 github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5 h1:Ii+DKncOVM8Cu1Hc+ETb5K+23HdAMvESYE3ZJ5b5cMI=
 github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE=
@@ -2256,6 +2263,8 @@ github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qq
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
 github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
+github.com/robfig/cron v1.2.0 h1:ZjScXvvxeQ63Dbyxy76Fj3AT3Ut0aKsyd2/tl3DTMuQ=
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
 github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
 github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
@@ -2482,6 +2491,10 @@ go.opentelemetry.io/proto/otlp v0.19.0/go.mod h1:H7XAot3MsfNsj7EXtrA2q5xSNQ10UqI
 go.opentelemetry.io/proto/otlp v1.0.0/go.mod h1:Sy6pihPLfYHkr3NkUbEhGHFhINUSI/v80hjKIs5JXpM=
 go.opentelemetry.io/proto/otlp v1.3.1 h1:TrMUixzpM0yuc/znrFTP9MMRh8trP93mkCiDVeXrui0=
 go.opentelemetry.io/proto/otlp v1.3.1/go.mod h1:0X1WI4de4ZsLrrJNLAQbFeLCm3T7yBkR0XqQ7niQU+8=
+go.temporal.io/api v1.40.0 h1:rH3HvUUCFr0oecQTBW5tI6DdDQsX2Xb6OFVgt/bvLto=
+go.temporal.io/api v1.40.0/go.mod h1:1WwYUMo6lao8yl0371xWUm13paHExN5ATYT/B7QtFis=
+go.temporal.io/sdk v1.30.0 h1:7jzSFZYk+tQ2kIYEP+dvrM7AW9EsCEP52JHCjVGuwbI=
+go.temporal.io/sdk v1.30.0/go.mod h1:Pv45F/fVDgWKx+jhix5t/dGgqROVaI+VjPLd3CHWqq0=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=

pkg/scalers/temporal.go

@@ -0,0 +1,249 @@
+package scalers
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/go-logr/logr"
+	sdk "go.temporal.io/sdk/client"
+	sdklog "go.temporal.io/sdk/log"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+	v2 "k8s.io/api/autoscaling/v2"
+	"k8s.io/metrics/pkg/apis/external_metrics"
+
+	"github.com/kedacore/keda/v2/pkg/scalers/scalersconfig"
+	kedautil "github.com/kedacore/keda/v2/pkg/util"
+)
+
+var (
+	temporalDefauleQueueTypes = []sdk.TaskQueueType{
+		sdk.TaskQueueTypeActivity,
+		sdk.TaskQueueTypeWorkflow,
+		sdk.TaskQueueTypeNexus,
+	}
+)
+
+type temporalScaler struct {
+	metricType v2.MetricTargetType
+	metadata   *temporalMetadata
+	tcl        sdk.Client
+	logger     logr.Logger
+}
+
+type temporalMetadata struct {
+	Endpoint                  string   `keda:"name=endpoint,                  order=triggerMetadata;resolvedEnv"`
+	Namespace                 string   `keda:"name=namespace,                 order=triggerMetadata;resolvedEnv, default=default"`
+	ActivationTargetQueueSize int64    `keda:"name=activationTargetQueueSize, order=triggerMetadata, default=0"`
+	TargetQueueSize           int64    `keda:"name=targetQueueSize,           order=triggerMetadata, default=5"`
+	TaskQueue                 string   `keda:"name=taskQueue,                 order=triggerMetadata;resolvedEnv"`
+	QueueTypes                []string `keda:"name=queueTypes,                order=triggerMetadata, optional"`
+	BuildID                   string   `keda:"name=buildId,                   order=triggerMetadata;resolvedEnv, optional"`
+	AllActive                 bool     `keda:"name=selectAllActive,           order=triggerMetadata, default=false"`
+	Unversioned               bool     `keda:"name=selectUnversioned,         order=triggerMetadata, default=false"`
+	APIKey                    string   `keda:"name=apiKey,                    order=authParams;resolvedEnv;triggerMetadata, optional"`
+	MinConnectTimeout         int      `keda:"name=minConnectTimeout,         order=triggerMetadata, default=5"`
+
+	UnsafeSsl   bool   `keda:"name=unsafeSsl,                 order=triggerMetadata, optional"`
+	Cert        string `keda:"name=cert,                      order=authParams, optional"`
+	Key         string `keda:"name=key,                       order=authParams, optional"`
+	KeyPassword string `keda:"name=keyPassword,               order=authParams, optional"`
+	CA          string `keda:"name=ca,                        order=authParams, optional"`
+
+	triggerIndex int
+}
+
+func (a *temporalMetadata) Validate() error {
+	if a.TargetQueueSize <= 0 {
+		return fmt.Errorf("targetQueueSize must be a positive number")
+	}
+	if a.ActivationTargetQueueSize < 0 {
+		return fmt.Errorf("activationTargetQueueSize must be a positive number")
+	}
+
+	if (a.Cert == "") != (a.Key == "") {
+		return fmt.Errorf("both cert and key must be provided when using TLS")
+	}
+
+	if a.MinConnectTimeout < 0 {
+		return fmt.Errorf("minConnectTimeout must be a positive number")
+	}
+
+	return nil
+}
+
+func NewTemporalScaler(ctx context.Context, config *scalersconfig.ScalerConfig) (Scaler, error) {
+	logger := InitializeLogger(config, "temporal_scaler")
+
+	metricType, err := GetMetricTargetType(config)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get scaler metric type: %w", err)
+	}
+
+	meta, err := parseTemporalMetadata(config, logger)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse Temporal metadata: %w", err)
+	}
+
+	c, err := getTemporalClient(ctx, meta, logger)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create Temporal client connection: %w", err)
+	}
+
+	return &temporalScaler{
+		metricType: metricType,
+		metadata:   meta,
+		tcl:        c,
+		logger:     logger,
+	}, nil
+}
+
+func (s *temporalScaler) Close(_ context.Context) error {
+	if s.tcl != nil {
+		s.tcl.Close()
+	}
+	return nil
+}
+
+func (s *temporalScaler) GetMetricSpecForScaling(context.Context) []v2.MetricSpec {
+	metricName := kedautil.NormalizeString(fmt.Sprintf("temporal-%s-%s", s.metadata.Namespace, s.metadata.TaskQueue))
+	externalMetric := &v2.ExternalMetricSource{
+		Metric: v2.MetricIdentifier{
+			Name: GenerateMetricNameWithIndex(s.metadata.triggerIndex, metricName),
+		},
+		Target: GetMetricTarget(s.metricType, s.metadata.TargetQueueSize),
+	}
+
+	metricSpec := v2.MetricSpec{
+		External: externalMetric,
+		Type:     externalMetricType,
+	}
+
+	return []v2.MetricSpec{metricSpec}
+}
+
+func (s *temporalScaler) GetMetricsAndActivity(ctx context.Context, metricName string) ([]external_metrics.ExternalMetricValue, bool, error) {
+	queueSize, err := s.getQueueSize(ctx)
+	if err != nil {
+		return nil, false, fmt.Errorf("failed to get Temporal queue size: %w", err)
+	}
+
+	metric := GenerateMetricInMili(metricName, float64(queueSize))
+
+	return []external_metrics.ExternalMetricValue{metric}, queueSize > s.metadata.ActivationTargetQueueSize, nil
+}
+
+func (s *temporalScaler) getQueueSize(ctx context.Context) (int64, error) {
+	var selection *sdk.TaskQueueVersionSelection
+	if s.metadata.AllActive || s.metadata.Unversioned || s.metadata.BuildID != "" {
+		selection = &sdk.TaskQueueVersionSelection{
+			AllActive:   s.metadata.AllActive,
+			Unversioned: s.metadata.Unversioned,
+			BuildIDs:    []string{s.metadata.BuildID},
+		}
+	}
+
+	queueType := getQueueTypes(s.metadata.QueueTypes)
+
+	resp, err := s.tcl.DescribeTaskQueueEnhanced(ctx, sdk.DescribeTaskQueueEnhancedOptions{
+		TaskQueue:      s.metadata.TaskQueue,
+		ReportStats:    true,
+		Versions:       selection,
+		TaskQueueTypes: queueType,
+	})
+	if err != nil {
+		return 0, fmt.Errorf("failed to get Temporal queue size: %w", err)
+	}
+
+	return getCombinedBacklogCount(resp), nil
+}
+
+func getQueueTypes(queueTypes []string) []sdk.TaskQueueType {
+	var taskQueueTypes []sdk.TaskQueueType
+	for _, t := range queueTypes {
+		var taskQueueType sdk.TaskQueueType
+		switch t {
+		case "workflow":
+			taskQueueType = sdk.TaskQueueTypeWorkflow
+		case "activity":
+			taskQueueType = sdk.TaskQueueTypeActivity
+		case "nexus":
+			taskQueueType = sdk.TaskQueueTypeNexus
+		}
+		taskQueueTypes = append(taskQueueTypes, taskQueueType)
+	}
+
+	if len(taskQueueTypes) == 0 {
+		return temporalDefauleQueueTypes
+	}
+	return taskQueueTypes
+}
+
+func getCombinedBacklogCount(description sdk.TaskQueueDescription) int64 {
+	var count int64
+	for _, versionInfo := range description.VersionsInfo {
+		for _, typeInfo := range versionInfo.TypesInfo {
+			if typeInfo.Stats != nil {
+				count += typeInfo.Stats.ApproximateBacklogCount
+			}
+		}
+	}
+	return count
+}
+
+func getTemporalClient(ctx context.Context, meta *temporalMetadata, log logr.Logger) (sdk.Client, error) {
+	logHandler := logr.ToSlogHandler(log)
+	options := sdk.Options{
+		HostPort:  meta.Endpoint,
+		Namespace: meta.Namespace,
+		Logger:    sdklog.NewStructuredLogger(slog.New(logHandler)),
+	}
+
+	dialOptions := []grpc.DialOption{
+		grpc.WithConnectParams(grpc.ConnectParams{
+			MinConnectTimeout: time.Duration(meta.MinConnectTimeout) * time.Second,
+		}),
+	}
+
+	if meta.APIKey != "" {
+		dialOptions = append(dialOptions, grpc.WithUnaryInterceptor(
+			func(ctx context.Context, method string, req any, reply any,
+				cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+				return invoker(
+					metadata.AppendToOutgoingContext(ctx, "temporal-namespace", meta.Namespace),
+					method,
+					req,
+					reply,
+					cc,
+					opts...,
+				)
+			},
+		))
+		options.Credentials = sdk.NewAPIKeyStaticCredentials(meta.APIKey)
+	}
+
+	options.ConnectionOptions = sdk.ConnectionOptions{
+		DialOptions: dialOptions,
+	}
+
+	if meta.Cert != "" && meta.Key != "" {
+		tlsConfig, err := kedautil.NewTLSConfigWithPassword(meta.Cert, meta.Key, meta.KeyPassword, meta.CA, meta.UnsafeSsl)
+		if err != nil {
+			return nil, err
+		}
+		options.ConnectionOptions.TLS = tlsConfig
+	}
+
+	return sdk.DialContext(ctx, options)
+}
+
+func parseTemporalMetadata(config *scalersconfig.ScalerConfig, _ logr.Logger) (*temporalMetadata, error) {
+	meta := &temporalMetadata{triggerIndex: config.TriggerIndex}
+	if err := config.TypedConfig(meta); err != nil {
+		return meta, fmt.Errorf("error parsing temporal metadata: %w", err)
+	}
+
+	return meta, nil
+}