refactor GenerateResourceRequirements and provide unit tests (#1822)

* refactor GenerateResourceRequirements and provide unit tests

charts/postgres-operator/crds/postgresqls.yaml

@@ -150,15 +150,9 @@ spec:
                     minimum: 1
                   resources:
                     type: object
-                    required:
-                      - requests
-                      - limits
                     properties:
                       limits:
                         type: object
-                        required:
-                          - cpu
-                          - memory
                         properties:
                           cpu:
                             type: string
@@ -168,9 +162,6 @@ spec:
                             pattern: '^(\d+(e\d+)?|\d+(\.\d+)?(e\d+)?[EPTGMK]i?)$'
                       requests:
                         type: object
-                        required:
-                          - cpu
-                          - memory
                         properties:
                           cpu:
                             type: string
@@ -406,15 +397,9 @@ spec:
                 description: deprecated
               resources:
                 type: object
-                required:
-                  - requests
-                  - limits
                 properties:
                   limits:
                     type: object
-                    required:
-                      - cpu
-                      - memory
                     properties:
                       cpu:
                         type: string
@@ -443,9 +428,6 @@ spec:
                         # than the corresponding limit.
                   requests:
                     type: object
-                    required:
-                      - cpu
-                      - memory
                     properties:
                       cpu:
                         type: string

docs/reference/cluster_manifest.md

@@ -322,9 +322,7 @@ explanation of `ttl` and `loop_wait` parameters.
 
 Those parameters define [CPU and memory requests and limits](https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/)
 for the Postgres container. They are grouped under the `resources` top-level
-key with subgroups `requests` and `limits`. The whole section is optional,
+key with subgroups `requests` and `limits`. 
-however if you specify a request or limit you have to define everything
-(unless you are not modifying the default CRD schema validation). 
 
 ### Requests
 

docs/reference/operator_parameters.md

@@ -159,9 +159,9 @@ Those are top-level keys, containing both leaf keys and groups.
   at the cost of overprovisioning memory and potential scheduling problems for
   containers with high memory limits due to the lack of memory on Kubernetes
   cluster nodes. This affects all containers created by the operator (Postgres,
-  Scalyr sidecar, and other sidecars except **sidecars** defined in the operator
+  connection pooler, logical backup, scalyr sidecar, and other sidecars except 
-  configuration); to set resources for the operator's own container, change the
+  **sidecars** defined in the operator configuration); to set resources for the
-  [operator deployment manually](https://github.com/zalando/postgres-operator/blob/master/manifests/postgres-operator.yaml#L20).
+  operator's own container, change the [operator deployment manually](https://github.com/zalando/postgres-operator/blob/master/manifests/postgres-operator.yaml#L20).
   The default is `false`.
 
 ## Postgres users

manifests/postgresql.crd.yaml

@@ -148,15 +148,9 @@ spec:
                     minimum: 1
                   resources:
                     type: object
-                    required:
-                      - requests
-                      - limits
                     properties:
                       limits:
                         type: object
-                        required:
-                          - cpu
-                          - memory
                         properties:
                           cpu:
                             type: string
@@ -166,9 +160,6 @@ spec:
                             pattern: '^(\d+(e\d+)?|\d+(\.\d+)?(e\d+)?[EPTGMK]i?)$'
                       requests:
                         type: object
-                        required:
-                          - cpu
-                          - memory
                         properties:
                           cpu:
                             type: string
@@ -404,15 +395,9 @@ spec:
                 description: deprecated
               resources:
                 type: object
-                required:
-                  - requests
-                  - limits
                 properties:
                   limits:
                     type: object
-                    required:
-                      - cpu
-                      - memory
                     properties:
                       cpu:
                         type: string
@@ -441,9 +426,6 @@ spec:
                         # than the corresponding limit.
                   requests:
                     type: object
-                    required:
-                      - cpu
-                      - memory
                     properties:
                       cpu:
                         type: string

pkg/apis/acid.zalan.do/v1/crds.go

@@ -239,11 +239,9 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 							},
 							"resources": {
 								Type: "object",
-								Required: []string{"requests", "limits"},
 								Properties: map[string]apiextv1.JSONSchemaProps{
 									"limits": {
 										Type: "object",
-										Required: []string{"cpu", "memory"},
 										Properties: map[string]apiextv1.JSONSchemaProps{
 											"cpu": {
 												Type:    "string",
@@ -257,7 +255,6 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 									},
 									"requests": {
 										Type: "object",
-										Required: []string{"cpu", "memory"},
 										Properties: map[string]apiextv1.JSONSchemaProps{
 											"cpu": {
 												Type:    "string",
@@ -649,11 +646,9 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 					},
 					"resources": {
 						Type: "object",
-						Required: []string{"requests", "limits"},
 						Properties: map[string]apiextv1.JSONSchemaProps{
 							"limits": {
 								Type: "object",
-								Required: []string{"cpu", "memory"},
 								Properties: map[string]apiextv1.JSONSchemaProps{
 									"cpu": {
 										Type:    "string",
@@ -667,7 +662,6 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 							},
 							"requests": {
 								Type: "object",
-								Required: []string{"cpu", "memory"},
 								Properties: map[string]apiextv1.JSONSchemaProps{
 									"cpu": {
 										Type:    "string",

pkg/apis/acid.zalan.do/v1/postgresql_type.go

@@ -167,7 +167,7 @@ type Patroni struct {
 	Slots                 map[string]map[string]string `json:"slots,omitempty"`
 	SynchronousMode       bool                         `json:"synchronous_mode,omitempty"`
 	SynchronousModeStrict bool                         `json:"synchronous_mode_strict,omitempty"`
-	SynchronousNodeCount  uint32                       `json:"synchronous_node_count,omitempty" defaults:1`
+	SynchronousNodeCount  uint32                       `json:"synchronous_node_count,omitempty" defaults:"1"`
 }
 
 // StandbyDescription contains s3 wal path

pkg/apis/acid.zalan.do/v1/zz_generated.deepcopy.go

@@ -106,7 +106,11 @@ func (in *ConnectionPooler) DeepCopyInto(out *ConnectionPooler) {
 		*out = new(int32)
 		**out = **in
 	}
-	out.Resources = in.Resources
+	if in.Resources != nil {
+		in, out := &in.Resources, &out.Resources
+		*out = new(Resources)
+		**out = **in
+	}
 	return
 }
 
@@ -575,7 +579,11 @@ func (in *PostgresSpec) DeepCopyInto(out *PostgresSpec) {
 	in.PostgresqlParam.DeepCopyInto(&out.PostgresqlParam)
 	in.Volume.DeepCopyInto(&out.Volume)
 	in.Patroni.DeepCopyInto(&out.Patroni)
-	out.Resources = in.Resources
+	if in.Resources != nil {
+		in, out := &in.Resources, &out.Resources
+		*out = new(Resources)
+		**out = **in
+	}
 	if in.EnableConnectionPooler != nil {
 		in, out := &in.EnableConnectionPooler, &out.EnableConnectionPooler
 		*out = new(bool)
@@ -1132,7 +1140,11 @@ func (in *ScalyrConfiguration) DeepCopy() *ScalyrConfiguration {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Sidecar) DeepCopyInto(out *Sidecar) {
 	*out = *in
-	out.Resources = in.Resources
+	if in.Resources != nil {
+		in, out := &in.Resources, &out.Resources
+		*out = new(Resources)
+		**out = **in
+	}
 	if in.Ports != nil {
 		in, out := &in.Ports, &out.Ports
 		*out = make([]corev1.ContainerPort, len(*in))

pkg/cluster/cluster.go

@@ -256,10 +256,6 @@ func (c *Cluster) Create() error {
 	c.KubeClient.SetPostgresCRDStatus(c.clusterName(), acidv1.ClusterStatusCreating)
 	c.eventRecorder.Event(c.GetReference(), v1.EventTypeNormal, "Create", "Started creation of new cluster resources")
 
-	if err = c.enforceMinResourceLimits(&c.Spec); err != nil {
-		return fmt.Errorf("could not enforce minimum resource limits: %v", err)
-	}
-
 	for _, role := range []PostgresRole{Master, Replica} {
 
 		if c.Endpoints[role] != nil {
@@ -676,50 +672,6 @@ func comparePorts(a, b []v1.ContainerPort) bool {
 	return true
 }
 
-func (c *Cluster) enforceMinResourceLimits(spec *acidv1.PostgresSpec) error {
-
-	var (
-		isSmaller bool
-		err       error
-	)
-
-	if spec.Resources == nil {
-		return nil
-	}
-
-	// setting limits too low can cause unnecessary evictions / OOM kills
-	minCPULimit := c.OpConfig.MinCPULimit
-	minMemoryLimit := c.OpConfig.MinMemoryLimit
-
-	cpuLimit := spec.Resources.ResourceLimits.CPU
-	if cpuLimit != "" {
-		isSmaller, err = util.IsSmallerQuantity(cpuLimit, minCPULimit)
-		if err != nil {
-			return fmt.Errorf("could not compare defined CPU limit %s with configured minimum value %s: %v", cpuLimit, minCPULimit, err)
-		}
-		if isSmaller {
-			c.logger.Warningf("defined CPU limit %s is below required minimum %s and will be increased", cpuLimit, minCPULimit)
-			c.eventRecorder.Eventf(c.GetReference(), v1.EventTypeWarning, "ResourceLimits", "defined CPU limit %s is below required minimum %s and will be set to it", cpuLimit, minCPULimit)
-			spec.Resources.ResourceLimits.CPU = minCPULimit
-		}
-	}
-
-	memoryLimit := spec.Resources.ResourceLimits.Memory
-	if memoryLimit != "" {
-		isSmaller, err = util.IsSmallerQuantity(memoryLimit, minMemoryLimit)
-		if err != nil {
-			return fmt.Errorf("could not compare defined memory limit %s with configured minimum value %s: %v", memoryLimit, minMemoryLimit, err)
-		}
-		if isSmaller {
-			c.logger.Warningf("defined memory limit %s is below required minimum %s and will be increased", memoryLimit, minMemoryLimit)
-			c.eventRecorder.Eventf(c.GetReference(), v1.EventTypeWarning, "ResourceLimits", "defined memory limit %s is below required minimum %s and will be set to it", memoryLimit, minMemoryLimit)
-			spec.Resources.ResourceLimits.Memory = minMemoryLimit
-		}
-	}
-
-	return nil
-}
-
 // Update changes Kubernetes objects according to the new specification. Unlike the sync case, the missing object
 // (i.e. service) is treated as an error
 // logical backup cron jobs are an exception: a user-initiated Update can enable a logical backup job
@@ -799,12 +751,6 @@ func (c *Cluster) Update(oldSpec, newSpec *acidv1.Postgresql) error {
 
 	// Statefulset
 	func() {
-		if err := c.enforceMinResourceLimits(&c.Spec); err != nil {
-			c.logger.Errorf("could not sync resources: %v", err)
-			updateFailed = true
-			return
-		}
-
 		oldSs, err := c.generateStatefulSet(&oldSpec.Spec)
 		if err != nil {
 			c.logger.Errorf("could not generate old statefulset spec: %v", err)
@@ -812,9 +758,6 @@ func (c *Cluster) Update(oldSpec, newSpec *acidv1.Postgresql) error {
 			return
 		}
 
-		// update newSpec to for latter comparison with oldSpec
-		c.enforceMinResourceLimits(&newSpec.Spec)
-
 		newSs, err := c.generateStatefulSet(&newSpec.Spec)
 		if err != nil {
 			c.logger.Errorf("could not generate new statefulset spec: %v", err)

pkg/cluster/connection_pooler.go

@@ -210,9 +210,10 @@ func (c *Cluster) generateConnectionPoolerPodTemplate(role PostgresRole) (
 		connectionPoolerSpec = &acidv1.ConnectionPooler{}
 	}
 	gracePeriod := int64(c.OpConfig.PodTerminateGracePeriod.Seconds())
-	resources, err := generateResourceRequirements(
+	resources, err := c.generateResourceRequirements(
 		connectionPoolerSpec.Resources,
-		makeDefaultConnectionPoolerResources(&c.OpConfig))
+		makeDefaultConnectionPoolerResources(&c.OpConfig),
+		connectionPoolerContainer)
 
 	effectiveDockerImage := util.Coalesce(
 		connectionPoolerSpec.DockerImage,
@@ -627,8 +628,9 @@ func (c *Cluster) needSyncConnectionPoolerDefaults(Config *Config, spec *acidv1.
 		reasons = append(reasons, msg)
 	}
 
-	expectedResources, err := generateResourceRequirements(spec.Resources,
+	expectedResources, err := c.generateResourceRequirements(spec.Resources,
-		makeDefaultConnectionPoolerResources(&Config.OpConfig))
+		makeDefaultConnectionPoolerResources(&Config.OpConfig),
+		connectionPoolerContainer)
 
 	// An error to generate expected resources means something is not quite
 	// right, but for the purpose of robustness do not panic here, just report

pkg/cluster/k8sres.go

@@ -37,6 +37,8 @@ const (
 	patroniPGBinariesParameterName = "bin_dir"
 	patroniPGHBAConfParameterName  = "pg_hba"
 	localHost                      = "127.0.0.1/32"
+	scalyrSidecarName              = "scalyr-sidecar"
+	logicalBackupContainerName     = "logical-backup"
 	connectionPoolerContainer      = "connection-pooler"
 	pgPort                         = 5432
 )
@@ -117,9 +119,7 @@ func (c *Cluster) podDisruptionBudgetName() string {
 	return c.OpConfig.PDBNameFormat.Format("cluster", c.Name)
 }
 
-func (c *Cluster) makeDefaultResources() acidv1.Resources {
+func makeDefaultResources(config *config.Config) acidv1.Resources {
-
-	config := c.OpConfig
 
 	defaultRequests := acidv1.ResourceDescription{
 		CPU:    config.Resources.DefaultCPURequest,
@@ -136,32 +136,61 @@ func (c *Cluster) makeDefaultResources() acidv1.Resources {
 	}
 }
 
-func generateResourceRequirements(resources *acidv1.Resources, defaultResources acidv1.Resources) (*v1.ResourceRequirements, error) {
+func (c *Cluster) enforceMinResourceLimits(resources *v1.ResourceRequirements) error {
-	var err error
+	var (
+		isSmaller bool
+		err       error
+		msg       string
+	)
 
-	var specRequests, specLimits acidv1.ResourceDescription
+	// setting limits too low can cause unnecessary evictions / OOM kills
-
+	cpuLimit := resources.Limits[v1.ResourceCPU]
-	if resources == nil {
+	minCPULimit := c.OpConfig.MinCPULimit
-		specRequests = acidv1.ResourceDescription{}
+	if minCPULimit != "" {
-		specLimits = acidv1.ResourceDescription{}
+		isSmaller, err = util.IsSmallerQuantity(cpuLimit.String(), minCPULimit)
-	} else {
-		specRequests = resources.ResourceRequests
-		specLimits = resources.ResourceLimits
-	}
-
-	result := v1.ResourceRequirements{}
-
-	result.Requests, err = fillResourceList(specRequests, defaultResources.ResourceRequests)
 		if err != nil {
-		return nil, fmt.Errorf("could not fill resource requests: %v", err)
+			return fmt.Errorf("could not compare defined CPU limit %s for %q container with configured minimum value %s: %v",
+				cpuLimit.String(), constants.PostgresContainerName, minCPULimit, err)
+		}
+		if isSmaller {
+			msg = fmt.Sprintf("defined CPU limit %s for %q container is below required minimum %s and will be increased",
+				cpuLimit.String(), constants.PostgresContainerName, minCPULimit)
+			c.logger.Warningf(msg)
+			c.eventRecorder.Eventf(c.GetReference(), v1.EventTypeWarning, "ResourceLimits", msg)
+			resources.Limits[v1.ResourceCPU], _ = resource.ParseQuantity(minCPULimit)
+		}
 	}
 
-	result.Limits, err = fillResourceList(specLimits, defaultResources.ResourceLimits)
+	memoryLimit := resources.Limits[v1.ResourceMemory]
+	minMemoryLimit := c.OpConfig.MinMemoryLimit
+	if minMemoryLimit != "" {
+		isSmaller, err = util.IsSmallerQuantity(memoryLimit.String(), minMemoryLimit)
 		if err != nil {
-		return nil, fmt.Errorf("could not fill resource limits: %v", err)
+			return fmt.Errorf("could not compare defined memory limit %s for %q container with configured minimum value %s: %v",
+				memoryLimit.String(), constants.PostgresContainerName, minMemoryLimit, err)
+		}
+		if isSmaller {
+			msg = fmt.Sprintf("defined memory limit %s for %q container is below required minimum %s and will be increased",
+				memoryLimit.String(), constants.PostgresContainerName, minMemoryLimit)
+			c.logger.Warningf(msg)
+			c.eventRecorder.Eventf(c.GetReference(), v1.EventTypeWarning, "ResourceLimits", msg)
+			resources.Limits[v1.ResourceMemory], _ = resource.ParseQuantity(minMemoryLimit)
+		}
 	}
 
-	return &result, nil
+	return nil
+}
+
+func setMemoryRequestToLimit(resources *v1.ResourceRequirements, containerName string, logger *logrus.Entry) {
+
+	requests := resources.Requests[v1.ResourceMemory]
+	limits := resources.Limits[v1.ResourceMemory]
+	isSmaller := requests.Cmp(limits) == -1
+	if isSmaller {
+		logger.Warningf("memory request of %s for %q container is increased to match memory limit of %s",
+			requests.String(), containerName, limits.String())
+		resources.Requests[v1.ResourceMemory] = limits
+	}
 }
 
 func fillResourceList(spec acidv1.ResourceDescription, defaults acidv1.ResourceDescription) (v1.ResourceList, error) {
@@ -194,6 +223,44 @@ func fillResourceList(spec acidv1.ResourceDescription, defaults acidv1.ResourceD
 	return requests, nil
 }
 
+func (c *Cluster) generateResourceRequirements(
+	resources *acidv1.Resources,
+	defaultResources acidv1.Resources,
+	containerName string) (*v1.ResourceRequirements, error) {
+	var err error
+	specRequests := acidv1.ResourceDescription{}
+	specLimits := acidv1.ResourceDescription{}
+	result := v1.ResourceRequirements{}
+
+	if resources != nil {
+		specRequests = resources.ResourceRequests
+		specLimits = resources.ResourceLimits
+	}
+
+	result.Requests, err = fillResourceList(specRequests, defaultResources.ResourceRequests)
+	if err != nil {
+		return nil, fmt.Errorf("could not fill resource requests: %v", err)
+	}
+
+	result.Limits, err = fillResourceList(specLimits, defaultResources.ResourceLimits)
+	if err != nil {
+		return nil, fmt.Errorf("could not fill resource limits: %v", err)
+	}
+
+	// enforce minimum cpu and memory limits for Postgres containers only
+	if containerName == constants.PostgresContainerName {
+		if err = c.enforceMinResourceLimits(&result); err != nil {
+			return nil, fmt.Errorf("could not enforce minimum resource limits: %v", err)
+		}
+	}
+
+	if c.OpConfig.SetMemoryRequestToLimit {
+		setMemoryRequestToLimit(&result, containerName, c.logger)
+	}
+
+	return &result, nil
+}
+
 func generateSpiloJSONConfiguration(pg *acidv1.PostgresqlParam, patroni *acidv1.Patroni, pamRoleName string, EnablePgVersionEnvVar bool, logger *logrus.Entry) (string, error) {
 	config := spiloConfiguration{}
 
@@ -514,8 +581,8 @@ func generateContainer(
 	}
 }
 
-func generateSidecarContainers(sidecars []acidv1.Sidecar,
+func (c *Cluster) generateSidecarContainers(sidecars []acidv1.Sidecar,
-	defaultResources acidv1.Resources, startIndex int, logger *logrus.Entry) ([]v1.Container, error) {
+	defaultResources acidv1.Resources, startIndex int) ([]v1.Container, error) {
 
 	if len(sidecars) > 0 {
 		result := make([]v1.Container, 0)
@@ -527,7 +594,7 @@ func generateSidecarContainers(sidecars []acidv1.Sidecar,
 				sidecar.Resources.DeepCopyInto(&resourcesSpec)
 			}
 
-			resources, err := generateResourceRequirements(&resourcesSpec, defaultResources)
+			resources, err := c.generateResourceRequirements(&resourcesSpec, defaultResources, sidecar.Name)
 			if err != nil {
 				return nil, err
 			}
@@ -1002,61 +1069,9 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*appsv1.Statef
 		additionalVolumes   = spec.AdditionalVolumes
 	)
 
-	// Improve me. Please.
+	defaultResources := makeDefaultResources(&c.OpConfig)
-	if c.OpConfig.SetMemoryRequestToLimit {
+	resourceRequirements, err := c.generateResourceRequirements(
-
+		spec.Resources, defaultResources, constants.PostgresContainerName)
-		// controller adjusts the default memory request at operator startup
-
-		var request, limit string
-
-		if spec.Resources == nil {
-			request = c.OpConfig.Resources.DefaultMemoryRequest
-			limit = c.OpConfig.Resources.DefaultMemoryLimit
-		} else {
-			request = spec.Resources.ResourceRequests.Memory
-			limit = spec.Resources.ResourceRequests.Memory
-		}
-
-		isSmaller, err := util.IsSmallerQuantity(request, limit)
-		if err != nil {
-			return nil, err
-		}
-		if isSmaller {
-			c.logger.Warningf("The memory request of %v for the Postgres container is increased to match the memory limit of %v.", request, limit)
-			spec.Resources.ResourceRequests.Memory = limit
-		}
-
-		// controller adjusts the Scalyr sidecar request at operator startup
-		// as this sidecar is managed separately
-
-		// adjust sidecar containers defined for that particular cluster
-		for _, sidecar := range spec.Sidecars {
-
-			// TODO #413
-			var sidecarRequest, sidecarLimit string
-
-			if sidecar.Resources == nil {
-				sidecarRequest = c.OpConfig.Resources.DefaultMemoryRequest
-				sidecarLimit = c.OpConfig.Resources.DefaultMemoryLimit
-			} else {
-				sidecarRequest = sidecar.Resources.ResourceRequests.Memory
-				sidecarLimit = sidecar.Resources.ResourceRequests.Memory
-			}
-
-			isSmaller, err := util.IsSmallerQuantity(sidecarRequest, sidecarLimit)
-			if err != nil {
-				return nil, err
-			}
-			if isSmaller {
-				c.logger.Warningf("The memory request of %v for the %v sidecar container is increased to match the memory limit of %v.", sidecar.Resources.ResourceRequests.Memory, sidecar.Name, sidecar.Resources.ResourceLimits.Memory)
-				sidecar.Resources.ResourceRequests.Memory = sidecar.Resources.ResourceLimits.Memory
-			}
-		}
-
-	}
-
-	defaultResources := c.makeDefaultResources()
-	resourceRequirements, err := generateResourceRequirements(spec.Resources, defaultResources)
 	if err != nil {
 		return nil, fmt.Errorf("could not generate resource requirements: %v", err)
 	}
@@ -1232,7 +1247,7 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*appsv1.Statef
 			c.logger.Warningf("sidecars specified but disabled in configuration - next statefulset creation would fail")
 		}
 
-		if clusterSpecificSidecars, err = generateSidecarContainers(spec.Sidecars, defaultResources, 0, c.logger); err != nil {
+		if clusterSpecificSidecars, err = c.generateSidecarContainers(spec.Sidecars, defaultResources, 0); err != nil {
 			return nil, fmt.Errorf("could not generate sidecar containers: %v", err)
 		}
 	}
@@ -1243,7 +1258,7 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*appsv1.Statef
 	for name, dockerImage := range c.OpConfig.SidecarImages {
 		globalSidecarsByDockerImage = append(globalSidecarsByDockerImage, acidv1.Sidecar{Name: name, DockerImage: dockerImage})
 	}
-	if globalSidecarContainersByDockerImage, err = generateSidecarContainers(globalSidecarsByDockerImage, defaultResources, len(clusterSpecificSidecars), c.logger); err != nil {
+	if globalSidecarContainersByDockerImage, err = c.generateSidecarContainers(globalSidecarsByDockerImage, defaultResources, len(clusterSpecificSidecars)); err != nil {
 		return nil, fmt.Errorf("could not generate sidecar containers: %v", err)
 	}
 	// make the resulting list reproducible
@@ -1256,7 +1271,7 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*appsv1.Statef
 	// generate scalyr sidecar container
 	var scalyrSidecars []v1.Container
 	if scalyrSidecar, err :=
-		generateScalyrSidecarSpec(c.Name,
+		c.generateScalyrSidecarSpec(c.Name,
 			c.OpConfig.ScalyrAPIKey,
 			c.OpConfig.ScalyrServerURL,
 			c.OpConfig.ScalyrImage,
@@ -1264,8 +1279,7 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*appsv1.Statef
 			c.OpConfig.ScalyrMemoryRequest,
 			c.OpConfig.ScalyrCPULimit,
 			c.OpConfig.ScalyrMemoryLimit,
-			defaultResources,
+			defaultResources); err != nil {
-			c.logger); err != nil {
 		return nil, fmt.Errorf("could not generate Scalyr sidecar: %v", err)
 	} else {
 		if scalyrSidecar != nil {
@@ -1375,12 +1389,12 @@ func (c *Cluster) generatePodAnnotations(spec *acidv1.PostgresSpec) map[string]s
 	return annotations
 }
 
-func generateScalyrSidecarSpec(clusterName, APIKey, serverURL, dockerImage string,
+func (c *Cluster) generateScalyrSidecarSpec(clusterName, APIKey, serverURL, dockerImage string,
 	scalyrCPURequest string, scalyrMemoryRequest string, scalyrCPULimit string, scalyrMemoryLimit string,
-	defaultResources acidv1.Resources, logger *logrus.Entry) (*v1.Container, error) {
+	defaultResources acidv1.Resources) (*v1.Container, error) {
 	if APIKey == "" || dockerImage == "" {
 		if APIKey == "" && dockerImage != "" {
-			logger.Warning("Not running Scalyr sidecar: SCALYR_API_KEY must be defined")
+			c.logger.Warning("Not running Scalyr sidecar: SCALYR_API_KEY must be defined")
 		}
 		return nil, nil
 	}
@@ -1390,7 +1404,8 @@ func generateScalyrSidecarSpec(clusterName, APIKey, serverURL, dockerImage strin
 		scalyrCPULimit,
 		scalyrMemoryLimit,
 	)
-	resourceRequirementsScalyrSidecar, err := generateResourceRequirements(&resourcesScalyrSidecar, defaultResources)
+	resourceRequirementsScalyrSidecar, err := c.generateResourceRequirements(
+		&resourcesScalyrSidecar, defaultResources, scalyrSidecarName)
 	if err != nil {
 		return nil, fmt.Errorf("invalid resources for Scalyr sidecar: %v", err)
 	}
@@ -1408,7 +1423,7 @@ func generateScalyrSidecarSpec(clusterName, APIKey, serverURL, dockerImage strin
 		env = append(env, v1.EnvVar{Name: "SCALYR_SERVER_URL", Value: serverURL})
 	}
 	return &v1.Container{
-		Name:            "scalyr-sidecar",
+		Name:            scalyrSidecarName,
 		Image:           dockerImage,
 		Env:             env,
 		ImagePullPolicy: v1.PullIfNotPresent,
@@ -1991,15 +2006,15 @@ func (c *Cluster) generateLogicalBackupJob() (*batchv1beta1.CronJob, error) {
 	c.logger.Debug("Generating logical backup pod template")
 
 	// allocate for the backup pod the same amount of resources as for normal DB pods
-	defaultResources := c.makeDefaultResources()
+	resourceRequirements, err = c.generateResourceRequirements(
-	resourceRequirements, err = generateResourceRequirements(c.Spec.Resources, defaultResources)
+		c.Spec.Resources, makeDefaultResources(&c.OpConfig), logicalBackupContainerName)
 	if err != nil {
 		return nil, fmt.Errorf("could not generate resource requirements for logical backup pods: %v", err)
 	}
 
 	envVars := c.generateLogicalBackupPodEnvVars()
 	logicalBackupContainer := generateContainer(
-		"logical-backup",
+		logicalBackupContainerName,
 		&c.OpConfig.LogicalBackup.LogicalBackupDockerImage,
 		resourceRequirements,
 		envVars,

pkg/cluster/k8sres_test.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/client-go/kubernetes/fake"
 	v1core "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/tools/record"
 )
 
 func newFakeK8sTestClient() (k8sutil.KubernetesClient, *fake.Clientset) {
@@ -1667,6 +1668,319 @@ func TestEnableLoadBalancers(t *testing.T) {
 	}
 }
 
+func TestGenerateResourceRequirements(t *testing.T) {
+	testName := "TestGenerateResourceRequirements"
+	client, _ := newFakeK8sTestClient()
+	clusterName := "acid-test-cluster"
+	namespace := "default"
+	clusterNameLabel := "cluster-name"
+	roleLabel := "spilo-role"
+	sidecarName := "postgres-exporter"
+
+	// two test cases will call enforceMinResourceLimits which emits 2 events per call
+	// hence bufferSize of 4 is required
+	newEventRecorder := record.NewFakeRecorder(4)
+
+	configResources := config.Resources{
+		ClusterLabels:        map[string]string{"application": "spilo"},
+		ClusterNameLabel:     clusterNameLabel,
+		DefaultCPURequest:    "100m",
+		DefaultCPULimit:      "1",
+		DefaultMemoryRequest: "100Mi",
+		DefaultMemoryLimit:   "500Mi",
+		MinCPULimit:          "250m",
+		MinMemoryLimit:       "250Mi",
+		PodRoleLabel:         roleLabel,
+	}
+
+	tests := []struct {
+		subTest           string
+		config            config.Config
+		pgSpec            acidv1.Postgresql
+		expectedResources acidv1.Resources
+	}{
+		{
+			subTest: "test generation of default resources when empty in manifest",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "1", Memory: "500Mi"},
+			},
+		},
+		{
+			subTest: "test generation of default resources for sidecar",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Sidecars: []acidv1.Sidecar{
+						acidv1.Sidecar{
+							Name: sidecarName,
+						},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "1", Memory: "500Mi"},
+			},
+		},
+		{
+			subTest: "test generation of resources when only requests are defined in manifest",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Resources: &acidv1.Resources{
+						ResourceRequests: acidv1.ResourceDescription{CPU: "50m", Memory: "50Mi"},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "50m", Memory: "50Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "1", Memory: "500Mi"},
+			},
+		},
+		{
+			subTest: "test generation of resources when only memory is defined in manifest",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Resources: &acidv1.Resources{
+						ResourceRequests: acidv1.ResourceDescription{Memory: "100Mi"},
+						ResourceLimits:   acidv1.ResourceDescription{Memory: "1Gi"},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "1", Memory: "1Gi"},
+			},
+		},
+		{
+			subTest: "test SetMemoryRequestToLimit flag",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: true,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "500Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "1", Memory: "500Mi"},
+			},
+		},
+		{
+			subTest: "test SetMemoryRequestToLimit flag for sidecar container, too",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: true,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Sidecars: []acidv1.Sidecar{
+						acidv1.Sidecar{
+							Name: sidecarName,
+							Resources: &acidv1.Resources{
+								ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "10Mi"},
+								ResourceLimits:   acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+							},
+						},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "100Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+			},
+		},
+		{
+			subTest: "test generating resources from manifest",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Resources: &acidv1.Resources{
+						ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "250Mi"},
+						ResourceLimits:   acidv1.ResourceDescription{CPU: "400m", Memory: "800Mi"},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "250Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "400m", Memory: "800Mi"},
+			},
+		},
+		{
+			subTest: "test enforcing min cpu and memory limit",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Resources: &acidv1.Resources{
+						ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+						ResourceLimits:   acidv1.ResourceDescription{CPU: "200m", Memory: "200Mi"},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "250m", Memory: "250Mi"},
+			},
+		},
+		{
+			subTest: "test min cpu and memory limit are not enforced on sidecar",
+			config: config.Config{
+				Resources:               configResources,
+				PodManagementPolicy:     "ordered_ready",
+				SetMemoryRequestToLimit: false,
+			},
+			pgSpec: acidv1.Postgresql{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      clusterName,
+					Namespace: namespace,
+				},
+				Spec: acidv1.PostgresSpec{
+					Sidecars: []acidv1.Sidecar{
+						acidv1.Sidecar{
+							Name: sidecarName,
+							Resources: &acidv1.Resources{
+								ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "10Mi"},
+								ResourceLimits:   acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+							},
+						},
+					},
+					TeamID: "acid",
+					Volume: acidv1.Volume{
+						Size: "1G",
+					},
+				},
+			},
+			expectedResources: acidv1.Resources{
+				ResourceRequests: acidv1.ResourceDescription{CPU: "10m", Memory: "10Mi"},
+				ResourceLimits:   acidv1.ResourceDescription{CPU: "100m", Memory: "100Mi"},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		var cluster = New(
+			Config{
+				OpConfig: tt.config,
+			}, client, tt.pgSpec, logger, newEventRecorder)
+
+		cluster.Name = clusterName
+		cluster.Namespace = namespace
+		_, err := cluster.createStatefulSet()
+		if k8sutil.ResourceAlreadyExists(err) {
+			err = cluster.syncStatefulSet()
+		}
+		assert.NoError(t, err)
+
+		containers := cluster.Statefulset.Spec.Template.Spec.Containers
+		clusterResources, err := parseResourceRequirements(containers[0].Resources)
+		if len(containers) > 1 {
+			clusterResources, err = parseResourceRequirements(containers[1].Resources)
+		}
+		assert.NoError(t, err)
+		if !reflect.DeepEqual(tt.expectedResources, clusterResources) {
+			t.Errorf("%s - %s: expected %#v but got %#v", testName, tt.subTest, tt.expectedResources, clusterResources)
+		}
+	}
+}
+
 func TestGenerateCapabilities(t *testing.T) {
 
 	testName := "TestGenerateCapabilities"

pkg/cluster/sync.go

@@ -76,11 +76,6 @@ func (c *Cluster) Sync(newSpec *acidv1.Postgresql) error {
 		}
 	}
 
-	if err = c.enforceMinResourceLimits(&c.Spec); err != nil {
-		err = fmt.Errorf("could not enforce minimum resource limits: %v", err)
-		return err
-	}
-
 	c.logger.Debug("syncing statefulsets")
 	if err = c.syncStatefulSet(); err != nil {
 		if !k8sutil.ResourceAlreadyExists(err) {

pkg/cluster/util.go

@@ -594,3 +594,15 @@ func trimCronjobName(name string) string {
 	}
 	return name
 }
+
+func parseResourceRequirements(resourcesRequirement v1.ResourceRequirements) (acidv1.Resources, error) {
+	var resources acidv1.Resources
+	resourcesJSON, err := json.Marshal(resourcesRequirement)
+	if err != nil {
+		return acidv1.Resources{}, fmt.Errorf("could not marshal K8s resources requirements")
+	}
+	if err = json.Unmarshal(resourcesJSON, &resources); err != nil {
+		return acidv1.Resources{}, fmt.Errorf("could not unmarshal K8s resources requirements into acidv1.Resources struct")
+	}
+	return resources, nil
+}