runtime: resource limits (kubernetes implementation) (#1931)

* runtime: add resource limit CreateOptions

* util/kubernetes/client: implement support for resource limits

* runtime/kubernetes: set resource limits for k8s deployments

* util/kubernetes: remove template check for ints

* util/kubernetes: fix incorrect yaml syntax

* runtime/kubernetes: fix incorrect units

* runtime: update create options to use Resources struct

runtime/kubernetes/service.go

@@ -2,6 +2,7 @@ package kubernetes
 
 import (
 	"encoding/json"
+	"fmt"
 	"strings"
 	"time"
 
@@ -102,6 +103,22 @@ func newService(s *runtime.Service, c runtime.CreateOptions) *service {
 		kdeploy.Spec.Template.PodSpec.Containers[0].Args = c.Args
 	}
 
+	// apply resource limits
+	if c.Resources != nil {
+		resLimits := &client.ResourceLimits{}
+		if c.Resources.CPU > 0 {
+			resLimits.CPU = fmt.Sprintf("%vm", c.Resources.CPU)
+		}
+		if c.Resources.Mem > 0 {
+			resLimits.Memory = fmt.Sprintf("%vMi", c.Resources.Mem)
+		}
+		if c.Resources.Disk > 0 {
+			resLimits.EphemeralStorage = fmt.Sprintf("%vMi", c.Resources.Disk)
+		}
+
+		kdeploy.Spec.Template.PodSpec.Containers[0].Resources = &client.ResourceRequirements{Limits: resLimits}
+	}
+
 	return &service{
 		Service:  s,
 		kservice: kservice,

runtime/options.go

@@ -84,6 +84,8 @@ type CreateOptions struct {
 	Context context.Context
 	// Secrets to use
 	Secrets map[string]string
+	// Resources to allocate the service
+	Resources *Resources
 }
 
 // ReadOptions queries runtime services
@@ -176,6 +178,13 @@ func WithOutput(out io.Writer) CreateOption {
 	}
 }
 
+// ResourceLimits sets the resources for the service to use
+func ResourceLimits(r *Resources) CreateOption {
+	return func(o *CreateOptions) {
+		o.Resources = r
+	}
+}
+
 // ReadService returns services with the given name
 func ReadService(service string) ReadOption {
 	return func(o *ReadOptions) {

runtime/runtime.go

@@ -104,3 +104,16 @@ type Service struct {
 	// Metadata stores metadata
 	Metadata map[string]string
 }
+
+// Resources which are allocated to a serivce
+type Resources struct {
+	// CPU is the maximum amount of CPU the service will be allocated (unit millicpu)
+	// e.g. 0.25CPU would be passed as 250
+	CPU int
+	// Mem is the maximum amount of memory the service will be allocated (unit mebibyte)
+	// e.g. 128 MiB of memory would be passed as 128
+	Mem int
+	// Disk is the maximum amount of disk space the service will be allocated (unit mebibyte)
+	// e.g. 128 MiB of memory would be passed as 128
+	Disk int
+}

util/kubernetes/client/templates.go

@@ -106,6 +106,39 @@ spec:
             periodSeconds: {{ .PeriodSeconds }}
           {{- end }}
           {{- end }}
+          {{- if .Resources }}
+          {{- with .Resources }}
+          resources:
+            {{- if .Limits }}
+            {{- with .Limits }}
+            limits:
+              {{- if .Memory }}
+              memory: {{ .Memory }}
+              {{- end }}
+              {{- if .CPU }}
+              cpu: {{ .CPU }}
+              {{- end }}
+              {{- if .EphemeralStorage }}
+              ephemeral-storage: {{ .EphemeralStorage }}
+              {{- end }}
+            {{- end }}
+            {{- end }}
+            {{- if .Requests }}
+            {{- with .Requests }}
+            requests:
+              {{- if .Memory }}
+              memory: {{ .Memory }}
+              {{- end }}
+              {{- if .CPU }}
+              cpu: {{ .CPU }}
+              {{- end }}
+              {{- if .EphemeralStorage }}
+              ephemeral-storage: {{ .EphemeralStorage }}
+              {{- end }}
+            {{- end }}
+            {{- end }}
+          {{- end }}
+          {{- end }}
       {{- end }}
       {{- end }}
 `

util/kubernetes/client/types.go

@@ -42,6 +42,7 @@ type Container struct {
 	Args           []string              `json:"args,omitempty"`
 	Ports          []ContainerPort       `json:"ports,omitempty"`
 	ReadinessProbe *Probe                `json:"readinessProbe,omitempty"`
+	Resources      *ResourceRequirements `json:"resources,omitempty"`
 }
 
 // DeploymentSpec defines micro deployment spec
@@ -234,3 +235,16 @@ type TCPSocketAction struct {
 	Host string `json:"host,omitempty"`
 	Port int    `json:"port,omitempty"`
 }
+
+// ResourceRequirements describes the compute resource requirements.
+type ResourceRequirements struct {
+	Limits   *ResourceLimits `json:"limits,omitempty"`
+	Requests *ResourceLimits `json:"requests,omitempty"`
+}
+
+// ResourceLimits describes the limits for a service
+type ResourceLimits struct {
+	Memory           string `json:"memory,omitempty"`
+	CPU              string `json:"cpu,omitempty"`
+	EphemeralStorage string `json:"ephemeral-storage,omitempty"`
+}