executor, scheduler: make default pod roles configurable

Currently if a pod is being scheduled with no meta.RolesKey label
attached to it, per convention the first configured mesos (framework)
role is being used.

This is quite limiting and also lets e2e tests fail. This commit
introduces a new configuration option "--mesos-default-pod-roles" defaulting to
"*" which defines the default pod roles in case the meta.RolesKey pod
label is missing.

contrib/mesos/pkg/scheduler/components/algorithm/algorithm.go

@@ -42,13 +42,14 @@ type SchedulerAlgorithm interface {
 
 // SchedulerAlgorithm implements the algorithm.ScheduleAlgorithm interface
 type schedulerAlgorithm struct {
-	sched        scheduler.Scheduler
-	podUpdates   queue.FIFO
-	podScheduler podschedulers.PodScheduler
-	prototype    *mesosproto.ExecutorInfo
-	roles        []string
-	defaultCpus  mresource.CPUShares
-	defaultMem   mresource.MegaBytes
+	sched           scheduler.Scheduler
+	podUpdates      queue.FIFO
+	podScheduler    podschedulers.PodScheduler
+	prototype       *mesosproto.ExecutorInfo
+	frameworkRoles  []string
+	defaultPodRoles []string
+	defaultCpus     mresource.CPUShares
+	defaultMem      mresource.MegaBytes
 }
 
 // New returns a new SchedulerAlgorithm
@@ -58,18 +59,19 @@ func New(
 	podUpdates queue.FIFO,
 	podScheduler podschedulers.PodScheduler,
 	prototype *mesosproto.ExecutorInfo,
-	roles []string,
+	frameworkRoles, defaultPodRoles []string,
 	defaultCpus mresource.CPUShares,
 	defaultMem mresource.MegaBytes,
 ) SchedulerAlgorithm {
 	return &schedulerAlgorithm{
-		sched:        sched,
-		podUpdates:   podUpdates,
-		podScheduler: podScheduler,
-		roles:        roles,
-		prototype:    prototype,
-		defaultCpus:  defaultCpus,
-		defaultMem:   defaultMem,
+		sched:           sched,
+		podUpdates:      podUpdates,
+		podScheduler:    podScheduler,
+		frameworkRoles:  frameworkRoles,
+		defaultPodRoles: defaultPodRoles,
+		prototype:       prototype,
+		defaultCpus:     defaultCpus,
+		defaultMem:      defaultMem,
 	}
 }
 
@@ -107,7 +109,7 @@ func (k *schedulerAlgorithm) Schedule(pod *api.Pod) (string, error) {
 		// From here on we can expect that the pod spec of a task has proper limits for CPU and memory.
 		k.limitPod(pod)
 
-		podTask, err := podtask.New(ctx, "", pod, k.prototype, k.roles)
+		podTask, err := podtask.New(ctx, "", pod, k.prototype, k.frameworkRoles, k.defaultPodRoles)
 		if err != nil {
 			log.Warningf("aborting Schedule, unable to create podtask object %+v: %v", pod, err)
 			return "", err