Introduce new preview auto-scaling mode for ARC. (#2153)

Co-authored-by: Cory Miller <cory-miller@github.com>
Co-authored-by: Nikola Jokic <nikola-jokic@github.com>
Co-authored-by: Ava Stancu <AvaStancu@github.com>
Co-authored-by: Ferenc Hammerl <fhammerl@github.com>
Co-authored-by: Francesco Renzi <rentziass@github.com>
Co-authored-by: Bassem Dghaidi <Link-@github.com>

cmd/githubrunnerscalesetlistener/main.go

@@ -0,0 +1,151 @@
+/*
+Copyright 2021 The actions-runner-controller authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/actions/actions-runner-controller/github/actions"
+	"github.com/actions/actions-runner-controller/logging"
+	"github.com/go-logr/logr"
+	"github.com/kelseyhightower/envconfig"
+)
+
+type RunnerScaleSetListenerConfig struct {
+	ConfigureUrl                string `split_words:"true"`
+	AppID                       int64  `split_words:"true"`
+	AppInstallationID           int64  `split_words:"true"`
+	AppPrivateKey               string `split_words:"true"`
+	Token                       string `split_words:"true"`
+	EphemeralRunnerSetNamespace string `split_words:"true"`
+	EphemeralRunnerSetName      string `split_words:"true"`
+	MaxRunners                  int    `split_words:"true"`
+	MinRunners                  int    `split_words:"true"`
+	RunnerScaleSetId            int    `split_words:"true"`
+}
+
+func main() {
+	logger, err := logging.NewLogger(logging.LogLevelDebug, logging.LogFormatText)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: creating logger: %v\n", err)
+		os.Exit(1)
+	}
+
+	var rc RunnerScaleSetListenerConfig
+	if err := envconfig.Process("github", &rc); err != nil {
+		logger.Error(err, "Error: processing environment variables for RunnerScaleSetListenerConfig")
+		os.Exit(1)
+	}
+
+	// Validate all inputs
+	if err := validateConfig(&rc); err != nil {
+		logger.Error(err, "Inputs validation failed")
+		os.Exit(1)
+	}
+
+	if err := run(rc, logger); err != nil {
+		logger.Error(err, "Run error")
+		os.Exit(1)
+	}
+}
+
+func run(rc RunnerScaleSetListenerConfig, logger logr.Logger) error {
+	// Create root context and hook with sigint and sigterm
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	creds := &actions.ActionsAuth{}
+	if rc.Token != "" {
+		creds.Token = rc.Token
+	} else {
+		creds.AppCreds = &actions.GitHubAppAuth{
+			AppID:             rc.AppID,
+			AppInstallationID: rc.AppInstallationID,
+			AppPrivateKey:     rc.AppPrivateKey,
+		}
+	}
+
+	actionsServiceClient, err := actions.NewClient(ctx, rc.ConfigureUrl, creds, "actions-runner-controller", logger)
+	if err != nil {
+		return fmt.Errorf("failed to create an Actions Service client: %w", err)
+	}
+
+	// Create message listener
+	autoScalerClient, err := NewAutoScalerClient(ctx, actionsServiceClient, &logger, rc.RunnerScaleSetId)
+	if err != nil {
+		return fmt.Errorf("failed to create a message listener: %w", err)
+	}
+	defer autoScalerClient.Close()
+
+	// Create kube manager and scale controller
+	kubeManager, err := NewKubernetesManager(&logger)
+	if err != nil {
+		return fmt.Errorf("failed to create kubernetes manager: %w", err)
+	}
+
+	scaleSettings := &ScaleSettings{
+		Namespace:    rc.EphemeralRunnerSetNamespace,
+		ResourceName: rc.EphemeralRunnerSetName,
+		MaxRunners:   rc.MaxRunners,
+		MinRunners:   rc.MinRunners,
+	}
+
+	service := NewService(ctx, autoScalerClient, kubeManager, scaleSettings, func(s *Service) {
+		s.logger = logger.WithName("service")
+	})
+
+	// Start listening for messages
+	if err = service.Start(); err != nil {
+		return fmt.Errorf("failed to start message queue listener: %w", err)
+	}
+	return nil
+}
+
+func validateConfig(config *RunnerScaleSetListenerConfig) error {
+	if len(config.ConfigureUrl) == 0 {
+		return fmt.Errorf("GitHubConfigUrl is not provided")
+	}
+
+	if len(config.EphemeralRunnerSetNamespace) == 0 || len(config.EphemeralRunnerSetName) == 0 {
+		return fmt.Errorf("EphemeralRunnerSetNamespace '%s' or EphemeralRunnerSetName '%s' is missing", config.EphemeralRunnerSetNamespace, config.EphemeralRunnerSetName)
+	}
+
+	if config.RunnerScaleSetId == 0 {
+		return fmt.Errorf("RunnerScaleSetId '%d' is missing", config.RunnerScaleSetId)
+	}
+
+	if config.MaxRunners < config.MinRunners {
+		return fmt.Errorf("MinRunners '%d' cannot be greater than MaxRunners '%d'", config.MinRunners, config.MaxRunners)
+	}
+
+	hasToken := len(config.Token) > 0
+	hasPrivateKeyConfig := config.AppID > 0 && config.AppPrivateKey != ""
+
+	if !hasToken && !hasPrivateKeyConfig {
+		return fmt.Errorf("GitHub auth credential is missing, token length: '%d', appId: '%d', installationId: '%d', private key length: '%d", len(config.Token), config.AppID, config.AppInstallationID, len(config.AppPrivateKey))
+	}
+
+	if hasToken && hasPrivateKeyConfig {
+		return fmt.Errorf("only one GitHub auth method supported at a time. Have both PAT and App auth: token length: '%d', appId: '%d', installationId: '%d', private key length: '%d", len(config.Token), config.AppID, config.AppInstallationID, len(config.AppPrivateKey))
+	}
+
+	return nil
+}