[WIP] Add set_memory_request_to_limit option (#406)

* Add set_memory_request_to_limit option

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

@@ -131,6 +131,7 @@ type OperatorConfigurationData struct {
 	PostgresUsersConfiguration PostgresUsersConfiguration   `json:"users"`
 	Kubernetes                 KubernetesMetaConfiguration  `json:"kubernetes"`
 	PostgresPodResources       PostgresPodResourcesDefaults `json:"postgres_pod_resources"`
+	SetMemoryRequestToLimit    bool                         `json:"set_memory_request_to_limit,omitempty"`
 	Timeouts                   OperatorTimeouts             `json:"timeouts"`
 	LoadBalancer               LoadBalancerConfiguration    `json:"load_balancer"`
 	AWSGCP                     AWSGCPConfiguration          `json:"aws_or_gcp"`

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

@@ -90,8 +90,8 @@ type ResourceDescription struct {
 
 // Resources describes requests and limits for the cluster resouces.
 type Resources struct {
-	ResourceRequest ResourceDescription `json:"requests,omitempty"`
-	ResourceLimits  ResourceDescription `json:"limits,omitempty"`
+	ResourceRequests ResourceDescription `json:"requests,omitempty"`
+	ResourceLimits   ResourceDescription `json:"limits,omitempty"`
 }
 
 // Patroni contains Patroni-specific configuration

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

@@ -240,8 +240,8 @@ var unmarshalCluster = []struct {
 					Slots:                map[string]map[string]string{"permanent_logical_1": {"type": "logical", "database": "foo", "plugin": "pgoutput"}},
 				},
 				Resources: Resources{
-					ResourceRequest: ResourceDescription{CPU: "10m", Memory: "50Mi"},
-					ResourceLimits:  ResourceDescription{CPU: "300m", Memory: "3000Mi"},
+					ResourceRequests: ResourceDescription{CPU: "10m", Memory: "50Mi"},
+					ResourceLimits:   ResourceDescription{CPU: "300m", Memory: "3000Mi"},
 				},
 
 				TeamID:              "ACID",

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

@@ -573,7 +573,7 @@ func (in *ResourceDescription) DeepCopy() *ResourceDescription {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Resources) DeepCopyInto(out *Resources) {
 	*out = *in
-	out.ResourceRequest = in.ResourceRequest
+	out.ResourceRequests = in.ResourceRequests
 	out.ResourceLimits = in.ResourceLimits
 	return
 }

pkg/cluster/k8sres.go

@@ -92,18 +92,18 @@ func (c *Cluster) makeDefaultResources() acidv1.Resources {
 	defaultRequests := acidv1.ResourceDescription{CPU: config.DefaultCPURequest, Memory: config.DefaultMemoryRequest}
 	defaultLimits := acidv1.ResourceDescription{CPU: config.DefaultCPULimit, Memory: config.DefaultMemoryLimit}
 
-	return acidv1.Resources{ResourceRequest: defaultRequests, ResourceLimits: defaultLimits}
+	return acidv1.Resources{ResourceRequests: defaultRequests, ResourceLimits: defaultLimits}
 }
 
 func generateResourceRequirements(resources acidv1.Resources, defaultResources acidv1.Resources) (*v1.ResourceRequirements, error) {
 	var err error
 
-	specRequests := resources.ResourceRequest
+	specRequests := resources.ResourceRequests
 	specLimits := resources.ResourceLimits
 
 	result := v1.ResourceRequirements{}
 
-	result.Requests, err = fillResourceList(specRequests, defaultResources.ResourceRequest)
+	result.Requests, err = fillResourceList(specRequests, defaultResources.ResourceRequests)
 	if err != nil {
 		return nil, fmt.Errorf("could not fill resource requests: %v", err)
 	}
@@ -377,8 +377,8 @@ func generateSidecarContainers(sidecars []acidv1.Sidecar,
 
 			resources, err := generateResourceRequirements(
 				makeResources(
-					sidecar.Resources.ResourceRequest.CPU,
-					sidecar.Resources.ResourceRequest.Memory,
+					sidecar.Resources.ResourceRequests.CPU,
+					sidecar.Resources.ResourceRequests.Memory,
 					sidecar.Resources.ResourceLimits.CPU,
 					sidecar.Resources.ResourceLimits.Memory,
 				),
@@ -625,7 +625,7 @@ func getBucketScopeSuffix(uid string) string {
 
 func makeResources(cpuRequest, memoryRequest, cpuLimit, memoryLimit string) acidv1.Resources {
 	return acidv1.Resources{
-		ResourceRequest: acidv1.ResourceDescription{
+		ResourceRequests: acidv1.ResourceDescription{
 			CPU:    cpuRequest,
 			Memory: memoryRequest,
 		},
@@ -644,6 +644,60 @@ func (c *Cluster) generateStatefulSet(spec *acidv1.PostgresSpec) (*v1beta1.State
 		podTemplate         *v1.PodTemplateSpec
 		volumeClaimTemplate *v1.PersistentVolumeClaim
 	)
+
+	if c.OpConfig.SetMemoryRequestToLimit {
+
+		// controller adjusts the default memory request at operator startup
+
+		request := spec.Resources.ResourceRequests.Memory
+		if request == "" {
+			request = c.OpConfig.DefaultMemoryRequest
+		}
+
+		limit := spec.Resources.ResourceLimits.Memory
+		if limit == "" {
+			limit = c.OpConfig.DefaultMemoryLimit
+		}
+
+		isSmaller, err := util.RequestIsSmallerThanLimit(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
+			sidecarRequest := sidecar.Resources.ResourceRequests.Memory
+			if request == "" {
+				request = c.OpConfig.DefaultMemoryRequest
+			}
+
+			sidecarLimit := sidecar.Resources.ResourceLimits.Memory
+			if limit == "" {
+				limit = c.OpConfig.DefaultMemoryLimit
+			}
+
+			isSmaller, err := util.RequestIsSmallerThanLimit(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)

pkg/controller/controller.go

@@ -110,6 +110,29 @@ func (c *Controller) initOperatorConfig() {
 	c.opConfig = config.NewFromMap(configMapData)
 	c.warnOnDeprecatedOperatorParameters()
 
+	if c.opConfig.SetMemoryRequestToLimit {
+
+		isSmaller, err := util.RequestIsSmallerThanLimit(c.opConfig.DefaultMemoryRequest, c.opConfig.DefaultMemoryLimit)
+		if err != nil {
+			panic(err)
+		}
+		if isSmaller {
+			c.logger.Warningf("The default memory request of %v for Postgres containers is increased to match the default memory limit of %v.", c.opConfig.DefaultMemoryRequest, c.opConfig.DefaultMemoryLimit)
+			c.opConfig.DefaultMemoryRequest = c.opConfig.DefaultMemoryLimit
+		}
+
+		isSmaller, err = util.RequestIsSmallerThanLimit(c.opConfig.ScalyrMemoryRequest, c.opConfig.ScalyrMemoryLimit)
+		if err != nil {
+			panic(err)
+		}
+		if isSmaller {
+			c.logger.Warningf("The memory request of %v for the Scalyr sidecar container is increased to match the memory limit of %v.", c.opConfig.ScalyrMemoryRequest, c.opConfig.ScalyrMemoryLimit)
+			c.opConfig.ScalyrMemoryRequest = c.opConfig.ScalyrMemoryLimit
+		}
+
+		// generateStatefulSet adjusts values for individual Postgres clusters
+	}
+
 }
 
 func (c *Controller) modifyConfigFromEnvironment() {

pkg/controller/operator_config.go

@@ -55,6 +55,7 @@ func (c *Controller) importConfigurationFromCRD(fromCRD *acidv1.OperatorConfigur
 	result.DefaultMemoryRequest = fromCRD.PostgresPodResources.DefaultMemoryRequest
 	result.DefaultCPULimit = fromCRD.PostgresPodResources.DefaultCPULimit
 	result.DefaultMemoryLimit = fromCRD.PostgresPodResources.DefaultMemoryLimit
+	result.SetMemoryRequestToLimit = fromCRD.SetMemoryRequestToLimit
 
 	result.ResourceCheckInterval = time.Duration(fromCRD.Timeouts.ResourceCheckInterval)
 	result.ResourceCheckTimeout = time.Duration(fromCRD.Timeouts.ResourceCheckTimeout)

pkg/util/config/config.go

@@ -104,6 +104,7 @@ type Config struct {
 	PodTerminateGracePeriod  time.Duration     `name:"pod_terminate_grace_period" default:"5m"`
 	ProtectedRoles           []string          `name:"protected_role_names" default:"admin"`
 	PostgresSuperuserTeams   []string          `name:"postgres_superuser_teams" default:""`
+	SetMemoryRequestToLimit  bool              `name:"set_memory_request_to_limit" defaults:"false"`
 }
 
 // MustMarshal marshals the config or panics

pkg/util/util.go

@@ -3,12 +3,14 @@ package util
 import (
 	"crypto/md5" // #nosec we need it to for PostgreSQL md5 passwords
 	"encoding/hex"
+	"fmt"
 	"math/rand"
 	"regexp"
 	"strings"
 	"time"
 
 	"github.com/motomux/pretty"
+	resource "k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/zalando-incubator/postgres-operator/pkg/spec"
@@ -127,3 +129,19 @@ func Coalesce(val, defaultVal string) string {
 	}
 	return val
 }
+
+// RequestIsSmallerThanLimit
+func RequestIsSmallerThanLimit(requestStr, limitStr string) (bool, error) {
+
+	request, err := resource.ParseQuantity(requestStr)
+	if err != nil {
+		return false, fmt.Errorf("could not parse memory request %v : %v", requestStr, err)
+	}
+
+	limit, err2 := resource.ParseQuantity(limitStr)
+	if err2 != nil {
+		return false, fmt.Errorf("could not parse memory limit %v : %v", limitStr, err2)
+	}
+
+	return request.Cmp(limit) == -1, nil
+}

pkg/util/util_test.go

@@ -69,6 +69,17 @@ var substringMatch = []struct {
 	{regexp.MustCompile(`aaaa (\d+) bbbb`), "aaaa 123 bbbb", nil},
 }
 
+var requestIsSmallerThanLimitTests = []struct {
+	request string
+	limit   string
+	out     bool
+}{
+	{"1G", "2G", true},
+	{"1G", "1Gi", true}, // G is 1000^3 bytes, Gi is 1024^3 bytes
+	{"1024Mi", "1G", false},
+	{"1e9", "1G", false}, // 1e9 bytes == 1G
+}
+
 func TestRandomPassword(t *testing.T) {
 	const pwdLength = 10
 	pwd := RandomPassword(pwdLength)
@@ -143,3 +154,15 @@ func TestMapContains(t *testing.T) {
 		}
 	}
 }
+
+func TestRequestIsSmallerThanLimit(t *testing.T) {
+	for _, tt := range requestIsSmallerThanLimitTests {
+		res, err := RequestIsSmallerThanLimit(tt.request, tt.limit)
+		if err != nil {
+			t.Errorf("RequestIsSmallerThanLimit returned unexpected error: %#v", err)
+		}
+		if res != tt.out {
+			t.Errorf("RequestIsSmallerThanLimit expected: %#v, got: %#v", tt.out, res)
+		}
+	}
+}