func()

in agent/engine/task_manager.go [1230:1310]

• 65 lines of code
• 7 McCabe index (conditional complexity)

func (mtask *managedTask) containerNextState(container *apicontainer.Container) *containerTransition {
	containerKnownStatus := container.GetKnownStatus()
	containerDesiredStatus := container.GetDesiredStatus()

	if containerKnownStatus == containerDesiredStatus {
		logger.Debug("Container at desired status", logger.Fields{
			field.TaskARN:       mtask.Arn,
			field.Container:     container.Name,
			field.RuntimeID:     container.GetRuntimeID(),
			field.DesiredStatus: containerDesiredStatus.String(),
		})
		return &containerTransition{
			nextState:      apicontainerstatus.ContainerStatusNone,
			actionRequired: false,
			reason:         dependencygraph.ContainerPastDesiredStatusErr,
		}
	}

	if containerKnownStatus > containerDesiredStatus {
		logger.Debug("Managed task [%s]: container [%s (Runtime ID: %s)] has already transitioned beyond desired status(%s): %s", logger.Fields{
			field.TaskARN:       mtask.Arn,
			field.Container:     container.Name,
			field.RuntimeID:     container.GetRuntimeID(),
			field.KnownStatus:   containerKnownStatus.String(),
			field.DesiredStatus: containerDesiredStatus.String(),
		})
		return &containerTransition{
			nextState:      apicontainerstatus.ContainerStatusNone,
			actionRequired: false,
			reason:         dependencygraph.ContainerPastDesiredStatusErr,
		}
	}
	if blocked, err := dependencygraph.DependenciesAreResolved(container, mtask.Containers,
		mtask.Task.GetExecutionCredentialsID(), mtask.credentialsManager, mtask.GetResources(), mtask.cfg); err != nil {
		logger.Debug("Can't apply state to container yet due to unresolved dependencies", logger.Fields{
			field.TaskARN:   mtask.Arn,
			field.Container: container.Name,
			field.RuntimeID: container.GetRuntimeID(),
			field.Error:     err,
		})
		return &containerTransition{
			nextState:      apicontainerstatus.ContainerStatusNone,
			actionRequired: false,
			reason:         err,
			blockedOn:      blocked,
		}
	}

	var nextState apicontainerstatus.ContainerStatus
	if container.DesiredTerminal() {
		nextState = apicontainerstatus.ContainerStopped
		// It's not enough to just check if container is in steady state here
		// we should really check if >= RUNNING <= STOPPED
		if !container.IsRunning() {
			// If the container's AppliedStatus is running, it means the StartContainer
			// api call has already been scheduled, we should not mark it as stopped
			// directly, because when the stopped container comes back, we will end up
			// with either:
			// 1. The task is not cleaned up, the handleStoppedToRunningContainerTransition
			// function will handle this case, but only once. If there are some
			// other stopped containers come back, they will not be stopped by
			// Agent.
			// 2. The task has already been cleaned up, in this case any stopped container
			// will not be stopped by Agent when they come back.
			if container.GetAppliedStatus() == apicontainerstatus.ContainerRunning {
				nextState = apicontainerstatus.ContainerStatusNone
			}

			return &containerTransition{
				nextState:      nextState,
				actionRequired: false,
			}
		}
	} else {
		nextState = container.GetNextKnownStateProgression()
	}
	return &containerTransition{
		nextState:      nextState,
		actionRequired: true,
	}
}