Propagate max capacity information to the actions back-end (#3431)

cmd/ghalistener/listener/listener.go

@@ -31,7 +31,7 @@ const (
 type Client interface {
 	GetAcquirableJobs(ctx context.Context, runnerScaleSetId int) (*actions.AcquirableJobList, error)
 	CreateMessageSession(ctx context.Context, runnerScaleSetId int, owner string) (*actions.RunnerScaleSetSession, error)
-	GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64) (*actions.RunnerScaleSetMessage, error)
+	GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*actions.RunnerScaleSetMessage, error)
 	DeleteMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, messageId int64) error
 	AcquireJobs(ctx context.Context, runnerScaleSetId int, messageQueueAccessToken string, requestIds []int64) ([]int64, error)
 	RefreshMessageSession(ctx context.Context, runnerScaleSetId int, sessionId *uuid.UUID) (*actions.RunnerScaleSetSession, error)
@@ -80,6 +80,7 @@ type Listener struct {
 
 	// updated fields
 	lastMessageID int64                          // The ID of the last processed message.
+	maxCapacity   int                            // The maximum number of runners that can be created.
 	session       *actions.RunnerScaleSetSession // The session for managing the runner scale set.
 }
 
@@ -93,6 +94,7 @@ func New(config Config) (*Listener, error) {
 		client:      config.Client,
 		logger:      config.Logger,
 		metrics:     metrics.Discard,
+		maxCapacity: config.MaxRunners,
 	}
 
 	if config.Metrics != nil {
@@ -267,7 +269,7 @@ func (l *Listener) createSession(ctx context.Context) error {
 
 func (l *Listener) getMessage(ctx context.Context) (*actions.RunnerScaleSetMessage, error) {
 	l.logger.Info("Getting next message", "lastMessageID", l.lastMessageID)
-	msg, err := l.client.GetMessage(ctx, l.session.MessageQueueUrl, l.session.MessageQueueAccessToken, l.lastMessageID)
+	msg, err := l.client.GetMessage(ctx, l.session.MessageQueueUrl, l.session.MessageQueueAccessToken, l.lastMessageID, l.maxCapacity)
 	if err == nil { // if NO error
 		return msg, nil
 	}
@@ -283,7 +285,7 @@ func (l *Listener) getMessage(ctx context.Context) (*actions.RunnerScaleSetMessa
 
 	l.logger.Info("Getting next message", "lastMessageID", l.lastMessageID)
 
-	msg, err = l.client.GetMessage(ctx, l.session.MessageQueueUrl, l.session.MessageQueueAccessToken, l.lastMessageID)
+	msg, err = l.client.GetMessage(ctx, l.session.MessageQueueUrl, l.session.MessageQueueAccessToken, l.lastMessageID, l.maxCapacity)
 	if err != nil { // if NO error
 		return nil, fmt.Errorf("failed to get next message after message session refresh: %w", err)
 	}

cmd/ghalistener/listener/listener_test.go

@@ -123,13 +123,14 @@ func TestListener_getMessage(t *testing.T) {
 		config := Config{
 			ScaleSetID: 1,
 			Metrics:    metrics.Discard,
+			MaxRunners: 10,
 		}
 
 		client := listenermocks.NewClient(t)
 		want := &actions.RunnerScaleSetMessage{
 			MessageId: 1,
 		}
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).Return(want, nil).Once()
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).Return(want, nil).Once()
 		config.Client = client
 
 		l, err := New(config)
@@ -148,10 +149,11 @@ func TestListener_getMessage(t *testing.T) {
 		config := Config{
 			ScaleSetID: 1,
 			Metrics:    metrics.Discard,
+			MaxRunners: 10,
 		}
 
 		client := listenermocks.NewClient(t)
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).Return(nil, &actions.HttpClientSideError{Code: http.StatusNotFound}).Once()
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).Return(nil, &actions.HttpClientSideError{Code: http.StatusNotFound}).Once()
 		config.Client = client
 
 		l, err := New(config)
@@ -170,6 +172,7 @@ func TestListener_getMessage(t *testing.T) {
 		config := Config{
 			ScaleSetID: 1,
 			Metrics:    metrics.Discard,
+			MaxRunners: 10,
 		}
 
 		client := listenermocks.NewClient(t)
@@ -185,12 +188,12 @@ func TestListener_getMessage(t *testing.T) {
 		}
 		client.On("RefreshMessageSession", ctx, mock.Anything, mock.Anything).Return(session, nil).Once()
 
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
 
 		want := &actions.RunnerScaleSetMessage{
 			MessageId: 1,
 		}
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).Return(want, nil).Once()
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).Return(want, nil).Once()
 
 		config.Client = client
 
@@ -214,6 +217,7 @@ func TestListener_getMessage(t *testing.T) {
 		config := Config{
 			ScaleSetID: 1,
 			Metrics:    metrics.Discard,
+			MaxRunners: 10,
 		}
 
 		client := listenermocks.NewClient(t)
@@ -229,7 +233,7 @@ func TestListener_getMessage(t *testing.T) {
 		}
 		client.On("RefreshMessageSession", ctx, mock.Anything, mock.Anything).Return(session, nil).Once()
 
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).Return(nil, &actions.MessageQueueTokenExpiredError{}).Twice()
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).Return(nil, &actions.MessageQueueTokenExpiredError{}).Twice()
 
 		config.Client = client
 
@@ -450,6 +454,7 @@ func TestListener_Listen(t *testing.T) {
 		config := Config{
 			ScaleSetID: 1,
 			Metrics:    metrics.Discard,
+			MaxRunners: 10,
 		}
 
 		client := listenermocks.NewClient(t)
@@ -470,7 +475,7 @@ func TestListener_Listen(t *testing.T) {
 			MessageType: "RunnerScaleSetJobMessages",
 			Statistics:  &actions.RunnerScaleSetStatistic{},
 		}
-		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything).
+		client.On("GetMessage", ctx, mock.Anything, mock.Anything, mock.Anything, 10).
 			Return(msg, nil).
 			Run(
 				func(mock.Arguments) {

cmd/ghalistener/listener/mocks/client.go

@@ -123,25 +123,25 @@ func (_m *Client) GetAcquirableJobs(ctx context.Context, runnerScaleSetId int) (
 	return r0, r1
 }
 
-// GetMessage provides a mock function with given fields: ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId
-func (_m *Client) GetMessage(ctx context.Context, messageQueueUrl string, messageQueueAccessToken string, lastMessageId int64) (*actions.RunnerScaleSetMessage, error) {
-	ret := _m.Called(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+// GetMessage provides a mock function with given fields: ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity
+func (_m *Client) GetMessage(ctx context.Context, messageQueueUrl string, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*actions.RunnerScaleSetMessage, error) {
+	ret := _m.Called(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 
 	var r0 *actions.RunnerScaleSetMessage
 	var r1 error
-	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64) (*actions.RunnerScaleSetMessage, error)); ok {
-		return rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64, int) (*actions.RunnerScaleSetMessage, error)); ok {
+		return rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	}
-	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64) *actions.RunnerScaleSetMessage); ok {
-		r0 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64, int) *actions.RunnerScaleSetMessage); ok {
+		r0 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).(*actions.RunnerScaleSetMessage)
 		}
 	}
 
-	if rf, ok := ret.Get(1).(func(context.Context, string, string, int64) error); ok {
-		r1 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(1).(func(context.Context, string, string, int64, int) error); ok {
+		r1 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	} else {
 		r1 = ret.Error(1)
 	}

cmd/githubrunnerscalesetlistener/autoScalerMessageListener.go

@@ -129,7 +129,7 @@ func (m *AutoScalerClient) Close() error {
 	return m.client.Close()
 }
 
-func (m *AutoScalerClient) GetRunnerScaleSetMessage(ctx context.Context, handler func(msg *actions.RunnerScaleSetMessage) error) error {
+func (m *AutoScalerClient) GetRunnerScaleSetMessage(ctx context.Context, handler func(msg *actions.RunnerScaleSetMessage) error, maxCapacity int) error {
 	if m.initialMessage != nil {
 		err := handler(m.initialMessage)
 		if err != nil {
@@ -141,7 +141,7 @@ func (m *AutoScalerClient) GetRunnerScaleSetMessage(ctx context.Context, handler
 	}
 
 	for {
-		message, err := m.client.GetMessage(ctx, m.lastMessageId)
+		message, err := m.client.GetMessage(ctx, m.lastMessageId, maxCapacity)
 		if err != nil {
 			return fmt.Errorf("get message failed from refreshing client. %w", err)
 		}

cmd/githubrunnerscalesetlistener/autoScalerMessageListener_test.go

@@ -317,7 +317,7 @@ func TestGetRunnerScaleSetMessage(t *testing.T) {
 		Statistics: &actions.RunnerScaleSetStatistic{},
 	}
 	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(&actions.RunnerScaleSetMessage{
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(&actions.RunnerScaleSetMessage{
 		MessageId:   1,
 		MessageType: "test",
 		Body:        "test",
@@ -332,7 +332,7 @@ func TestGetRunnerScaleSetMessage(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.NoError(t, err, "Error getting message")
 	assert.Equal(t, int64(0), asClient.lastMessageId, "Initial message")
@@ -340,7 +340,7 @@ func TestGetRunnerScaleSetMessage(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.NoError(t, err, "Error getting message")
 	assert.Equal(t, int64(1), asClient.lastMessageId, "Last message id should be updated")
@@ -368,7 +368,7 @@ func TestGetRunnerScaleSetMessage_HandleFailed(t *testing.T) {
 		Statistics: &actions.RunnerScaleSetStatistic{},
 	}
 	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(&actions.RunnerScaleSetMessage{
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(&actions.RunnerScaleSetMessage{
 		MessageId:   1,
 		MessageType: "test",
 		Body:        "test",
@@ -383,14 +383,14 @@ func TestGetRunnerScaleSetMessage_HandleFailed(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.NoError(t, err, "Error getting message")
 
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return fmt.Errorf("error")
-	})
+	}, 10)
 
 	assert.ErrorContains(t, err, "handle message failed. error", "Error getting message")
 	assert.Equal(t, int64(0), asClient.lastMessageId, "Last message id should not be updated")
@@ -419,7 +419,7 @@ func TestGetRunnerScaleSetMessage_HandleInitialMessage(t *testing.T) {
 			TotalAssignedJobs:  2,
 		},
 	}
-	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
+	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything, mock.Anything).Return(session, nil)
 	mockActionsClient.On("GetAcquirableJobs", ctx, 1).Return(&actions.AcquirableJobList{
 		Count: 1,
 		Jobs: []actions.AcquirableJob{
@@ -439,7 +439,7 @@ func TestGetRunnerScaleSetMessage_HandleInitialMessage(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.NoError(t, err, "Error getting message")
 	assert.Nil(t, asClient.initialMessage, "Initial message should be nil")
@@ -488,7 +488,7 @@ func TestGetRunnerScaleSetMessage_HandleInitialMessageFailed(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return fmt.Errorf("error")
-	})
+	}, 10)
 
 	assert.ErrorContains(t, err, "fail to process initial message. error", "Error getting message")
 	assert.NotNil(t, asClient.initialMessage, "Initial message should be nil")
@@ -516,8 +516,8 @@ func TestGetRunnerScaleSetMessage_RetryUntilGetMessage(t *testing.T) {
 		Statistics: &actions.RunnerScaleSetStatistic{},
 	}
 	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(nil, nil).Times(3)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(&actions.RunnerScaleSetMessage{
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(nil, nil).Times(3)
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(&actions.RunnerScaleSetMessage{
 		MessageId:   1,
 		MessageType: "test",
 		Body:        "test",
@@ -532,13 +532,13 @@ func TestGetRunnerScaleSetMessage_RetryUntilGetMessage(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 	assert.NoError(t, err, "Error getting initial message")
 
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.NoError(t, err, "Error getting message")
 	assert.Equal(t, int64(1), asClient.lastMessageId, "Last message id should be updated")
@@ -565,7 +565,7 @@ func TestGetRunnerScaleSetMessage_ErrorOnGetMessage(t *testing.T) {
 		Statistics: &actions.RunnerScaleSetStatistic{},
 	}
 	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(nil, fmt.Errorf("error"))
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(nil, fmt.Errorf("error"))
 
 	asClient, err := NewAutoScalerClient(ctx, mockActionsClient, &logger, 1, func(asc *AutoScalerClient) {
 		asc.client = mockSessionClient
@@ -575,12 +575,12 @@ func TestGetRunnerScaleSetMessage_ErrorOnGetMessage(t *testing.T) {
 	// process initial message
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		return nil
-	})
+	}, 10)
 	assert.NoError(t, err, "Error getting initial message")
 
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		return fmt.Errorf("Should not be called")
-	})
+	}, 10)
 
 	assert.ErrorContains(t, err, "get message failed from refreshing client. error", "Error should be returned")
 	assert.Equal(t, int64(0), asClient.lastMessageId, "Last message id should be updated")
@@ -608,7 +608,7 @@ func TestDeleteRunnerScaleSetMessage_Error(t *testing.T) {
 		Statistics: &actions.RunnerScaleSetStatistic{},
 	}
 	mockActionsClient.On("CreateMessageSession", ctx, 1, mock.Anything).Return(session, nil)
-	mockSessionClient.On("GetMessage", ctx, int64(0)).Return(&actions.RunnerScaleSetMessage{
+	mockSessionClient.On("GetMessage", ctx, int64(0), mock.Anything).Return(&actions.RunnerScaleSetMessage{
 		MessageId:   1,
 		MessageType: "test",
 		Body:        "test",
@@ -623,13 +623,13 @@ func TestDeleteRunnerScaleSetMessage_Error(t *testing.T) {
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 	assert.NoError(t, err, "Error getting initial message")
 
 	err = asClient.GetRunnerScaleSetMessage(ctx, func(msg *actions.RunnerScaleSetMessage) error {
 		logger.Info("Message received", "messageId", msg.MessageId, "messageType", msg.MessageType, "body", msg.Body)
 		return nil
-	})
+	}, 10)
 
 	assert.ErrorContains(t, err, "delete message failed from refreshing client. error", "Error getting message")
 	assert.Equal(t, int64(1), asClient.lastMessageId, "Last message id should be updated")

cmd/githubrunnerscalesetlistener/autoScalerService.go

@@ -89,7 +89,7 @@ func (s *Service) Start() error {
 			s.logger.Info("service is stopped.")
 			return nil
 		default:
-			err := s.rsClient.GetRunnerScaleSetMessage(s.ctx, s.processMessage)
+			err := s.rsClient.GetRunnerScaleSetMessage(s.ctx, s.processMessage, s.settings.MaxRunners)
 			if err != nil {
 				return fmt.Errorf("could not get and process message. %w", err)
 			}

cmd/githubrunnerscalesetlistener/autoScalerService_test.go

@@ -64,7 +64,7 @@ func TestStart(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything).Run(func(args mock.Arguments) { cancel() }).Return(nil).Once()
+	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything, mock.Anything).Run(func(mock.Arguments) { cancel() }).Return(nil).Once()
 
 	err = service.Start()
 
@@ -98,7 +98,7 @@ func TestStart_ScaleToMinRunners(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	mockRsClient.On("GetRunnerScaleSetMessage", ctx, mock.Anything).Run(func(args mock.Arguments) {
+	mockRsClient.On("GetRunnerScaleSetMessage", ctx, mock.Anything, mock.Anything).Run(func(args mock.Arguments) {
 		_ = service.scaleForAssignedJobCount(5)
 	}).Return(nil)
 
@@ -137,7 +137,7 @@ func TestStart_ScaleToMinRunnersFailed(t *testing.T) {
 	require.NoError(t, err)
 
 	c := mockKubeManager.On("ScaleEphemeralRunnerSet", ctx, service.settings.Namespace, service.settings.ResourceName, 5).Return(fmt.Errorf("error")).Once()
-	mockRsClient.On("GetRunnerScaleSetMessage", ctx, mock.Anything).Run(func(args mock.Arguments) {
+	mockRsClient.On("GetRunnerScaleSetMessage", ctx, mock.Anything, mock.Anything).Run(func(args mock.Arguments) {
 		_ = service.scaleForAssignedJobCount(5)
 	}).Return(c.ReturnArguments.Get(0))
 
@@ -172,8 +172,8 @@ func TestStart_GetMultipleMessages(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything).Return(nil).Times(5)
-	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything).Run(func(args mock.Arguments) { cancel() }).Return(nil).Once()
+	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything, mock.Anything).Return(nil).Times(5)
+	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything, mock.Anything).Run(func(args mock.Arguments) { cancel() }).Return(nil).Once()
 
 	err = service.Start()
 
@@ -207,8 +207,8 @@ func TestStart_ErrorOnMessage(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything).Return(nil).Times(2)
-	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything).Return(fmt.Errorf("error")).Once()
+	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything, mock.Anything).Return(nil).Times(2)
+	mockRsClient.On("GetRunnerScaleSetMessage", service.ctx, mock.Anything, mock.Anything).Return(fmt.Errorf("error")).Once()
 
 	err = service.Start()
 

cmd/githubrunnerscalesetlistener/messageListener.go

@@ -8,6 +8,6 @@ import (
 
 //go:generate mockery --inpackage --name=RunnerScaleSetClient
 type RunnerScaleSetClient interface {
-	GetRunnerScaleSetMessage(ctx context.Context, handler func(msg *actions.RunnerScaleSetMessage) error) error
+	GetRunnerScaleSetMessage(ctx context.Context, handler func(msg *actions.RunnerScaleSetMessage) error, maxCapacity int) error
 	AcquireJobsForRunnerScaleSet(ctx context.Context, requestIds []int64) error
 }

cmd/githubrunnerscalesetlistener/mock_RunnerScaleSetClient.go

@@ -29,13 +29,13 @@ func (_m *MockRunnerScaleSetClient) AcquireJobsForRunnerScaleSet(ctx context.Con
 	return r0
 }
 
-// GetRunnerScaleSetMessage provides a mock function with given fields: ctx, handler
-func (_m *MockRunnerScaleSetClient) GetRunnerScaleSetMessage(ctx context.Context, handler func(*actions.RunnerScaleSetMessage) error) error {
-	ret := _m.Called(ctx, handler)
+// GetRunnerScaleSetMessage provides a mock function with given fields: ctx, handler, maxCapacity
+func (_m *MockRunnerScaleSetClient) GetRunnerScaleSetMessage(ctx context.Context, handler func(*actions.RunnerScaleSetMessage) error, maxCapacity int) error {
+	ret := _m.Called(ctx, handler, maxCapacity)
 
 	var r0 error
-	if rf, ok := ret.Get(0).(func(context.Context, func(*actions.RunnerScaleSetMessage) error) error); ok {
-		r0 = rf(ctx, handler)
+	if rf, ok := ret.Get(0).(func(context.Context, func(*actions.RunnerScaleSetMessage) error, int) error); ok {
+		r0 = rf(ctx, handler, maxCapacity)
 	} else {
 		r0 = ret.Error(0)
 	}

cmd/githubrunnerscalesetlistener/sessionrefreshingclient.go

@@ -24,8 +24,12 @@ func newSessionClient(client actions.ActionsService, logger *logr.Logger, sessio
 	}
 }
 
-func (m *SessionRefreshingClient) GetMessage(ctx context.Context, lastMessageId int64) (*actions.RunnerScaleSetMessage, error) {
-	message, err := m.client.GetMessage(ctx, m.session.MessageQueueUrl, m.session.MessageQueueAccessToken, lastMessageId)
+func (m *SessionRefreshingClient) GetMessage(ctx context.Context, lastMessageId int64, maxCapacity int) (*actions.RunnerScaleSetMessage, error) {
+	if maxCapacity < 0 {
+		return nil, fmt.Errorf("maxCapacity must be greater than or equal to 0")
+	}
+
+	message, err := m.client.GetMessage(ctx, m.session.MessageQueueUrl, m.session.MessageQueueAccessToken, lastMessageId, maxCapacity)
 	if err == nil {
 		return message, nil
 	}
@@ -42,7 +46,7 @@ func (m *SessionRefreshingClient) GetMessage(ctx context.Context, lastMessageId
 	}
 
 	m.session = session
-	message, err = m.client.GetMessage(ctx, m.session.MessageQueueUrl, m.session.MessageQueueAccessToken, lastMessageId)
+	message, err = m.client.GetMessage(ctx, m.session.MessageQueueUrl, m.session.MessageQueueAccessToken, lastMessageId, maxCapacity)
 	if err != nil {
 		return nil, fmt.Errorf("delete message failed after refresh message session. %w", err)
 	}

cmd/githubrunnerscalesetlistener/sessionrefreshingclient_test.go

@@ -31,17 +31,17 @@ func TestGetMessage(t *testing.T) {
 		},
 	}
 
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0)).Return(nil, nil).Once()
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0)).Return(&actions.RunnerScaleSetMessage{MessageId: 1}, nil).Once()
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0), 10).Return(nil, nil).Once()
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0), 10).Return(&actions.RunnerScaleSetMessage{MessageId: 1}, nil).Once()
 
 	client := newSessionClient(mockActionsClient, &logger, session)
 
-	msg, err := client.GetMessage(ctx, 0)
+	msg, err := client.GetMessage(ctx, 0, 10)
 	require.NoError(t, err, "GetMessage should not return an error")
 
 	assert.Nil(t, msg, "GetMessage should return nil message")
 
-	msg, err = client.GetMessage(ctx, 0)
+	msg, err = client.GetMessage(ctx, 0, 10)
 	require.NoError(t, err, "GetMessage should not return an error")
 
 	assert.Equal(t, int64(1), msg.MessageId, "GetMessage should return a message with id 1")
@@ -146,11 +146,11 @@ func TestGetMessage_Error(t *testing.T) {
 		},
 	}
 
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0)).Return(nil, fmt.Errorf("error")).Once()
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0), 10).Return(nil, fmt.Errorf("error")).Once()
 
 	client := newSessionClient(mockActionsClient, &logger, session)
 
-	msg, err := client.GetMessage(ctx, 0)
+	msg, err := client.GetMessage(ctx, 0, 10)
 	assert.ErrorContains(t, err, "get message failed. error", "GetMessage should return an error")
 	assert.Nil(t, msg, "GetMessage should return nil message")
 	assert.True(t, mockActionsClient.AssertExpectations(t), "All expected calls to mockActionsClient should have been made")
@@ -227,8 +227,8 @@ func TestGetMessage_RefreshToken(t *testing.T) {
 			Id: 1,
 		},
 	}
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0)).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, "token2", int64(0)).Return(&actions.RunnerScaleSetMessage{
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0), 10).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, "token2", int64(0), 10).Return(&actions.RunnerScaleSetMessage{
 		MessageId:   1,
 		MessageType: "test",
 		Body:        "test",
@@ -243,7 +243,7 @@ func TestGetMessage_RefreshToken(t *testing.T) {
 	}, nil).Once()
 
 	client := newSessionClient(mockActionsClient, &logger, session)
-	msg, err := client.GetMessage(ctx, 0)
+	msg, err := client.GetMessage(ctx, 0, 10)
 	assert.NoError(t, err, "Error getting message")
 	assert.Equal(t, int64(1), msg.MessageId, "message id should be updated")
 	assert.Equal(t, "token2", client.session.MessageQueueAccessToken, "Message queue access token should be updated")
@@ -340,11 +340,11 @@ func TestGetMessage_RefreshToken_Failed(t *testing.T) {
 			Id: 1,
 		},
 	}
-	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0)).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
+	mockActionsClient.On("GetMessage", ctx, session.MessageQueueUrl, session.MessageQueueAccessToken, int64(0), 10).Return(nil, &actions.MessageQueueTokenExpiredError{}).Once()
 	mockActionsClient.On("RefreshMessageSession", ctx, session.RunnerScaleSet.Id, session.SessionId).Return(nil, fmt.Errorf("error"))
 
 	client := newSessionClient(mockActionsClient, &logger, session)
-	msg, err := client.GetMessage(ctx, 0)
+	msg, err := client.GetMessage(ctx, 0, 10)
 	assert.ErrorContains(t, err, "refresh message session failed. error", "Error should be returned")
 	assert.Nil(t, msg, "Message should be nil")
 	assert.Equal(t, "token", client.session.MessageQueueAccessToken, "Message queue access token should not be updated")

github/actions/client.go

@@ -29,6 +29,9 @@ const (
 	apiVersionQueryParam = "api-version=6.0-preview"
 )
 
+// Header used to propagate capacity information to the back-end
+const HeaderScaleSetMaxCapacity = "X-ScaleSetMaxCapacity"
+
 //go:generate mockery --inpackage --name=ActionsService
 type ActionsService interface {
 	GetRunnerScaleSet(ctx context.Context, runnerGroupId int, runnerScaleSetName string) (*RunnerScaleSet, error)
@@ -45,7 +48,7 @@ type ActionsService interface {
 	AcquireJobs(ctx context.Context, runnerScaleSetId int, messageQueueAccessToken string, requestIds []int64) ([]int64, error)
 	GetAcquirableJobs(ctx context.Context, runnerScaleSetId int) (*AcquirableJobList, error)
 
-	GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64) (*RunnerScaleSetMessage, error)
+	GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*RunnerScaleSetMessage, error)
 	DeleteMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, messageId int64) error
 
 	GenerateJitRunnerConfig(ctx context.Context, jitRunnerSetting *RunnerScaleSetJitRunnerSetting, scaleSetId int) (*RunnerScaleSetJitRunnerConfig, error)
@@ -104,6 +107,8 @@ type Client struct {
 	proxyFunc ProxyFunc
 }
 
+var _ ActionsService = &Client{}
+
 type ProxyFunc func(req *http.Request) (*url.URL, error)
 
 type ClientOption func(*Client)
@@ -543,7 +548,7 @@ func (c *Client) DeleteRunnerScaleSet(ctx context.Context, runnerScaleSetId int)
 	return nil
 }
 
-func (c *Client) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64) (*RunnerScaleSetMessage, error) {
+func (c *Client) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*RunnerScaleSetMessage, error) {
 	u, err := url.Parse(messageQueueUrl)
 	if err != nil {
 		return nil, err
@@ -555,6 +560,10 @@ func (c *Client) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAc
 		u.RawQuery = q.Encode()
 	}
 
+	if maxCapacity < 0 {
+		return nil, fmt.Errorf("maxCapacity must be greater than or equal to 0")
+	}
+
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
 	if err != nil {
 		return nil, err
@@ -563,6 +572,7 @@ func (c *Client) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAc
 	req.Header.Set("Accept", "application/json; api-version=6.0-preview")
 	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", messageQueueAccessToken))
 	req.Header.Set("User-Agent", c.userAgent.String())
+	req.Header.Set(HeaderScaleSetMaxCapacity, strconv.Itoa(maxCapacity))
 
 	resp, err := c.Do(req)
 	if err != nil {

github/actions/client_runner_scale_set_message_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
+	"strconv"
 	"testing"
 	"time"
 
@@ -35,7 +36,7 @@ func TestGetMessage(t *testing.T) {
 		client, err := actions.NewClient(s.configURLForOrg("my-org"), auth)
 		require.NoError(t, err)
 
-		got, err := client.GetMessage(ctx, s.URL, token, 0)
+		got, err := client.GetMessage(ctx, s.URL, token, 0, 10)
 		require.NoError(t, err)
 		assert.Equal(t, want, got)
 	})
@@ -52,7 +53,7 @@ func TestGetMessage(t *testing.T) {
 		client, err := actions.NewClient(s.configURLForOrg("my-org"), auth)
 		require.NoError(t, err)
 
-		got, err := client.GetMessage(ctx, s.URL, token, 1)
+		got, err := client.GetMessage(ctx, s.URL, token, 1, 10)
 		require.NoError(t, err)
 		assert.Equal(t, want, got)
 	})
@@ -76,7 +77,7 @@ func TestGetMessage(t *testing.T) {
 		)
 		require.NoError(t, err)
 
-		_, err = client.GetMessage(ctx, server.URL, token, 0)
+		_, err = client.GetMessage(ctx, server.URL, token, 0, 10)
 		assert.NotNil(t, err)
 		assert.Equalf(t, actualRetry, expectedRetry, "A retry was expected after the first request but got: %v", actualRetry)
 	})
@@ -89,7 +90,7 @@ func TestGetMessage(t *testing.T) {
 		client, err := actions.NewClient(server.configURLForOrg("my-org"), auth)
 		require.NoError(t, err)
 
-		_, err = client.GetMessage(ctx, server.URL, token, 0)
+		_, err = client.GetMessage(ctx, server.URL, token, 0, 10)
 		require.NotNil(t, err)
 
 		var expectedErr *actions.MessageQueueTokenExpiredError
@@ -108,7 +109,7 @@ func TestGetMessage(t *testing.T) {
 		client, err := actions.NewClient(server.configURLForOrg("my-org"), auth)
 		require.NoError(t, err)
 
-		_, err = client.GetMessage(ctx, server.URL, token, 0)
+		_, err = client.GetMessage(ctx, server.URL, token, 0, 10)
 		require.NotNil(t, err)
 		assert.Equal(t, want.Error(), err.Error())
 	})
@@ -122,9 +123,35 @@ func TestGetMessage(t *testing.T) {
 		client, err := actions.NewClient(server.configURLForOrg("my-org"), auth)
 		require.NoError(t, err)
 
-		_, err = client.GetMessage(ctx, server.URL, token, 0)
+		_, err = client.GetMessage(ctx, server.URL, token, 0, 10)
 		assert.NotNil(t, err)
 	})
+
+	t.Run("Capacity error handling", func(t *testing.T) {
+		server := newActionsServer(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			hc := r.Header.Get(actions.HeaderScaleSetMaxCapacity)
+			c, err := strconv.Atoi(hc)
+			require.NoError(t, err)
+			assert.GreaterOrEqual(t, c, 0)
+
+			w.WriteHeader(http.StatusBadRequest)
+			w.Header().Set("Content-Type", "text/plain")
+		}))
+
+		client, err := actions.NewClient(server.configURLForOrg("my-org"), auth)
+		require.NoError(t, err)
+
+		_, err = client.GetMessage(ctx, server.URL, token, 0, -1)
+		require.Error(t, err)
+		// Ensure we don't send requests with negative capacity
+		assert.False(t, errors.Is(err, &actions.ActionsError{}))
+
+		_, err = client.GetMessage(ctx, server.URL, token, 0, 0)
+		assert.Error(t, err)
+		var expectedErr *actions.ActionsError
+		assert.ErrorAs(t, err, &expectedErr)
+		assert.Equal(t, http.StatusBadRequest, expectedErr.StatusCode)
+	})
 }
 
 func TestDeleteMessage(t *testing.T) {

github/actions/errors.go

@@ -47,7 +47,6 @@ func (e *ActionsError) IsException(target string) bool {
 	if ex, ok := e.Err.(*ActionsExceptionError); ok {
 		return strings.Contains(ex.ExceptionName, target)
 	}
-
 	return false
 }
 

github/actions/fake/client.go

@@ -259,7 +259,7 @@ func (f *FakeClient) GetAcquirableJobs(ctx context.Context, runnerScaleSetId int
 	return f.getAcquirableJobsResult.AcquirableJobList, f.getAcquirableJobsResult.err
 }
 
-func (f *FakeClient) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64) (*actions.RunnerScaleSetMessage, error) {
+func (f *FakeClient) GetMessage(ctx context.Context, messageQueueUrl, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*actions.RunnerScaleSetMessage, error) {
 	return f.getMessageResult.RunnerScaleSetMessage, f.getMessageResult.err
 }
 

github/actions/mock_ActionsService.go

@@ -186,25 +186,25 @@ func (_m *MockActionsService) GetAcquirableJobs(ctx context.Context, runnerScale
 	return r0, r1
 }
 
-// GetMessage provides a mock function with given fields: ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId
-func (_m *MockActionsService) GetMessage(ctx context.Context, messageQueueUrl string, messageQueueAccessToken string, lastMessageId int64) (*RunnerScaleSetMessage, error) {
-	ret := _m.Called(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+// GetMessage provides a mock function with given fields: ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity
+func (_m *MockActionsService) GetMessage(ctx context.Context, messageQueueUrl string, messageQueueAccessToken string, lastMessageId int64, maxCapacity int) (*RunnerScaleSetMessage, error) {
+	ret := _m.Called(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 
 	var r0 *RunnerScaleSetMessage
 	var r1 error
-	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64) (*RunnerScaleSetMessage, error)); ok {
-		return rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64, int) (*RunnerScaleSetMessage, error)); ok {
+		return rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	}
-	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64) *RunnerScaleSetMessage); ok {
-		r0 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, string, string, int64, int) *RunnerScaleSetMessage); ok {
+		r0 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).(*RunnerScaleSetMessage)
 		}
 	}
 
-	if rf, ok := ret.Get(1).(func(context.Context, string, string, int64) error); ok {
-		r1 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId)
+	if rf, ok := ret.Get(1).(func(context.Context, string, string, int64, int) error); ok {
+		r1 = rf(ctx, messageQueueUrl, messageQueueAccessToken, lastMessageId, maxCapacity)
 	} else {
 		r1 = ret.Error(1)
 	}

github/actions/mock_SessionService.go

@@ -67,25 +67,25 @@ func (_m *MockSessionService) DeleteMessage(ctx context.Context, messageId int64
 	return r0
 }
 
-// GetMessage provides a mock function with given fields: ctx, lastMessageId
-func (_m *MockSessionService) GetMessage(ctx context.Context, lastMessageId int64) (*RunnerScaleSetMessage, error) {
-	ret := _m.Called(ctx, lastMessageId)
+// GetMessage provides a mock function with given fields: ctx, lastMessageId, maxCapacity
+func (_m *MockSessionService) GetMessage(ctx context.Context, lastMessageId int64, maxCapacity int) (*RunnerScaleSetMessage, error) {
+	ret := _m.Called(ctx, lastMessageId, maxCapacity)
 
 	var r0 *RunnerScaleSetMessage
 	var r1 error
-	if rf, ok := ret.Get(0).(func(context.Context, int64) (*RunnerScaleSetMessage, error)); ok {
-		return rf(ctx, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, int64, int) (*RunnerScaleSetMessage, error)); ok {
+		return rf(ctx, lastMessageId, maxCapacity)
 	}
-	if rf, ok := ret.Get(0).(func(context.Context, int64) *RunnerScaleSetMessage); ok {
-		r0 = rf(ctx, lastMessageId)
+	if rf, ok := ret.Get(0).(func(context.Context, int64, int) *RunnerScaleSetMessage); ok {
+		r0 = rf(ctx, lastMessageId, maxCapacity)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).(*RunnerScaleSetMessage)
 		}
 	}
 
-	if rf, ok := ret.Get(1).(func(context.Context, int64) error); ok {
-		r1 = rf(ctx, lastMessageId)
+	if rf, ok := ret.Get(1).(func(context.Context, int64, int) error); ok {
+		r1 = rf(ctx, lastMessageId, maxCapacity)
 	} else {
 		r1 = ret.Error(1)
 	}

github/actions/sessionservice.go

@@ -7,7 +7,7 @@ import (
 
 //go:generate mockery --inpackage --name=SessionService
 type SessionService interface {
-	GetMessage(ctx context.Context, lastMessageId int64) (*RunnerScaleSetMessage, error)
+	GetMessage(ctx context.Context, lastMessageId int64, maxCapacity int) (*RunnerScaleSetMessage, error)
 	DeleteMessage(ctx context.Context, messageId int64) error
 	AcquireJobs(ctx context.Context, requestIds []int64) ([]int64, error)
 	io.Closer