add max resource logic to the parallel steps

hack/release.sh

@@ -48,7 +48,7 @@ export K8S_CLUSTER_OVERRIDE=CLUSTER_NOT_SET
 export K8S_USER_OVERRIDE=USER_NOT_SET
 export DOCKER_REPO_OVERRIDE=DOCKER_NOT_SET
 
-# Build the base image for creds-init and git images.
+# Build the base image for creds-init and git images. 
 docker build -t ${BUILD_BASE_GCR} -f images/Dockerfile images/
 
 echo "Building build-crd"

pkg/reconciler/build/resources/pod.go

@@ -856,6 +856,64 @@ func GetRemoteEntrypoint(cache *Cache, image string, kubeclient kubernetes.Inter
 // TODO(aaron-prindle) setup the cache properly
 var cache = NewCache()
 
+func compareResources(a *corev1.ResourceRequirements, b *corev1.ResourceRequirements) bool {
+	equal := true
+	if a != nil {
+		equal = compareResoucesAssumeFirstNotNil(a, b)
+	}
+	if equal && (b != nil) {
+		equal = compareResoucesAssumeFirstNotNil(b, a)
+	}
+
+	return equal
+}
+
+func compareResoucesAssumeFirstNotNil(a *corev1.ResourceRequirements, b *corev1.ResourceRequirements) bool {
+	if b == nil || (len(b.Requests) == 0) {
+		return len(a.Requests) == 0
+	}
+	for k, v := range a.Requests {
+		if (&v).Cmp(b.Requests[k]) != 0 {
+			return false
+		}
+	}
+	for k, v := range a.Limits {
+		if (&v).Cmp(b.Limits[k]) != 0 {
+			return false
+		}
+	}
+	return true
+
+}
+
+func getMaxMemFromContainers(containers []corev1.Container) resource.Quantity {
+	if len(containers) == 0 {
+		return resource.Quantity{}
+	}
+	maxMem := *containers[0].Resources.Limits.Memory()
+	for _, c := range containers {
+		cmp := maxMem.Cmp(*c.Resources.Limits.Memory())
+		if cmp == -1 { //if max is less than this value
+			maxMem = *c.Resources.Limits.Cpu()
+		}
+	}
+	return maxMem
+}
+
+func getMaxCPUFromContainers(containers []corev1.Container) resource.Quantity {
+	if len(containers) == 0 {
+		return resource.Quantity{}
+	}
+	maxCPU := *containers[0].Resources.Limits.Cpu()
+	for _, c := range containers {
+		cmp := maxCPU.Cmp(*c.Resources.Limits.Cpu())
+		if cmp == -1 { //if max is less than this value
+			maxCPU = *c.Resources.Limits.Cpu()
+		}
+	}
+	return maxCPU
+}
+
 // RedirectSteps will modify each of the steps/containers such that
 // the binary being run is no longer the one specified by the Command
 // and the Args, but is instead the entrypoint binary, which will
@@ -873,7 +931,22 @@ func RedirectSteps(steps []corev1.Container, kubeclient kubernetes.Interface, bu
 			step.Command = ep
 		}
 		e, err := getEnvVar(step.Command, step.Args, i)
-		if i != 0 {
+
+		// As containers are now all started together but only one container is ran at a time
+		// rewrite the ResourceRequirements to reflect only one container will run
+		if i == 0 {
+			// find the max resource requirement
+			maxCPU := getMaxCPUFromContainers(steps)
+			maxMem := getMaxMemFromContainers(steps)
+			step.Resources = corev1.ResourceRequirements{
+				Limits: corev1.ResourceList{
+					// Must set memory limit to get MemoryStats.AvailableBytes
+					corev1.ResourceCPU:    maxCPU,
+					corev1.ResourceMemory: maxMem,
+				},
+			}
+
+		} else {
 			step.Resources = corev1.ResourceRequirements{
 				Limits: corev1.ResourceList{
 					// Must set memory limit to get MemoryStats.AvailableBytes