Add commandline flags for exclusion of specific namespaces and setting the default memory requests

README.MD

@@ -0,0 +1,4 @@
+# Default-request-adder
+A small container which periodically (every 10s) checks for a LimitRange on all non-excluded namespaces named `extreme-request-defaults` and creates it using the configured memory settings if absent.
+
+See the example-dir for an example deployment-file.

example/deploy.yaml

@@ -0,0 +1,38 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: default-request-adder
+  name: default-request-adder
+  namespace: kube-system
+  annotations:
+    kubernetes.io/change-cause: "${TIMESTAMP} Deployed commit id: ${COMMIT}"
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: default-request-adder
+  strategy:
+    rollingUpdate:
+      maxSurge: 1
+      maxUnavailable: 1
+    type: RollingUpdate
+  template:
+    metadata:
+      labels:
+        app: default-request-adder
+    spec:
+      containers:
+        - name: default-request-adder
+          resources:
+            limits:
+              memory: "50Mi"
+            requests:
+              memory: "50Mi"
+          imagePullPolicy: Always
+          image: registry.gitlab.com/unboundsoftware/default-request-adder:1.0
+          args:
+            - /default-request-adder
+            - -excluded-ns=kube-system,ingress-nginx
+            - -memory=1Pi
+      restartPolicy: Always

go.mod

@@ -21,7 +21,7 @@ require (
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.2.2 // indirect
-	k8s.io/api v0.0.0-20181128191700-6db15a15d2d3 // indirect
+	k8s.io/api v0.0.0-20181128191700-6db15a15d2d3
 	k8s.io/apimachinery v0.0.0-20181128191346-49ce2735e507
 	k8s.io/client-go v9.0.0+incompatible
 )

main.go

@@ -1,15 +1,26 @@
 package main
 
 import (
+	"flag"
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"log"
+	"strings"
+	"time"
 )
 
+type args struct {
+	ExcludedNS *string
+	Memory     *string
+	_          struct{}
+}
+
 func main() {
+	args := parseArgs()
+
 	config, err := rest.InClusterConfig()
 	if err != nil {
 		panic(err.Error())
@@ -18,32 +29,67 @@ func main() {
 	if err != nil {
 		panic(err.Error())
 	}
-	namespaces, err := clientset.CoreV1().Namespaces().List(metav1.ListOptions{})
+
+	memory, err := resource.ParseQuantity(*args.Memory)
 	if err != nil {
 		panic(err.Error())
 	}
+	log.Printf("Memory: %v", memory.String())
 
-	for _, ns := range namespaces.Items {
-		log.Printf("Checking for LimitRange named extreme-request-defaults in namespace '%v'\n", ns.Name)
-		if limitRange, err := clientset.CoreV1().LimitRanges(ns.Name).List(metav1.ListOptions{FieldSelector: "metadata.name=extreme-request-defaults"}); err == nil && len(limitRange.Items) == 0 {
-			log.Printf("Trying to create LimitaRange\n")
-			limits := []v1.LimitRangeItem{
-				{
-					DefaultRequest: v1.ResourceList{"memory": *resource.NewQuantity(1024*1024*1024*1024, resource.BinarySI)},
-					Type:           "Container",
-				},
-			}
-			limitRange := v1.LimitRange{
-				Spec: v1.LimitRangeSpec{Limits: limits},
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "extreme-request-defaults",
-				},
-			}
-			if _, err := clientset.CoreV1().LimitRanges(ns.Name).Create(&limitRange); err != nil {
-				log.Printf("Unable to create LimitRange in namespace '%v': Error: %v\n", ns.Name, err)
-			} else {
-				log.Printf("LimitRange extreme-request-defaults created in namespace '%v'\n", ns.Name)
+	limits := []v1.LimitRangeItem{
+		{
+			DefaultRequest: v1.ResourceList{"memory": memory},
+			Type:           "Container",
+		},
+	}
+	limitRange := v1.LimitRange{
+		Spec: v1.LimitRangeSpec{Limits: limits},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "extreme-request-defaults",
+		},
+	}
+
+	excludedNS := strings.Split(*args.ExcludedNS, ",")
+
+	for {
+		namespaces, err := clientset.CoreV1().Namespaces().List(metav1.ListOptions{})
+		if err != nil {
+			panic(err.Error())
+		}
+
+		for _, ns := range namespaces.Items {
+			if !nsExcluded(ns.Name, excludedNS) {
+				log.Printf("Checking for LimitRange named extreme-request-defaults in namespace '%v'\n", ns.Name)
+				if limitRanges, err := clientset.CoreV1().LimitRanges(ns.Name).List(metav1.ListOptions{FieldSelector: "metadata.name=extreme-request-defaults"}); err == nil && len(limitRanges.Items) == 0 {
+					log.Printf("Trying to create LimitRange\n")
+					if _, err := clientset.CoreV1().LimitRanges(ns.Name).Create(&limitRange); err != nil {
+						log.Printf("Unable to create LimitRange in namespace '%v': Error: %v\n", ns.Name, err)
+					} else {
+						log.Printf("LimitRange extreme-request-defaults created in namespace '%v'\n", ns.Name)
+					}
+				}
 			}
 		}
+
+		time.Sleep(10 * time.Second)
 	}
 }
+
+func nsExcluded(name string, excludedNS []string) bool {
+	for _, ns := range excludedNS {
+		if name == ns {
+			return true
+		}
+	}
+	return false
+}
+
+func parseArgs() args {
+	args := args{
+		ExcludedNS: flag.String("excluded-ns", "kube-system", "Comma-separated list of namespaces to be excluded"),
+		Memory:     flag.String("memory", "1Ti", "The default memory requests to set in the LimitRange. Default: 1Ti"),
+	}
+	flag.Parse()
+
+	return args
+}