Merge pull request #6 from ElisaOyj/addreadme

add readme

README.md

@@ -1 +1,96 @@
-# resource-advisor
+# Kubernetes Resource Advisor
+
+### Installation
+
+```
+export PLUGIN_VERSION=1.0.4
+
+# MacOS (x86_64)
+curl -sLo /usr/local/bin/kubectl-advisory https://github.com/ElisaOyj/kubernetes-resource-advisor/releases/download/${PLUGIN_VERSION}/resource-advisor-darwin-amd64
+
+# MacOS (M1)
+curl -sLo /usr/local/bin/kubectl-advisory https://github.com/ElisaOyj/kubernetes-resource-advisor/releases/download/${PLUGIN_VERSION}/resource-advisor-darwin-arm64
+
+# Linux (x86_64)
+curl -sLo /usr/local/bin/kubectl-advisory https://github.com/ElisaOyj/kubernetes-resource-advisor/releases/download/${PLUGIN_VERSION}/resource-advisor-linux-amd64
+
+# All
+chmod 755 /usr/local/bin/kubectl-advisory
+```
+
+You need to store the binary under PATH to make it usable as kubectl plugin.
+
+### Usage
+
+```
+kubectl advisory --help
+I0916 13:28:02.492261   96935 start.go:23] Starting application...
+Kubernetes resource-advisor
+
+Usage:
+  resource-advisor [flags]
+
+Flags:
+  -h, --help                        help for resource-advisor
+      --limit-margin string         Limit margin (default "1.2")
+      --namespace-selector string   Namespace selector
+      --namespaces string           Comma separated namespaces to be scanned
+      --quantile string             Quantile to be used (default "0.95")
+```
+
+```
+% kubectl advisory
+I0916 13:26:56.442083   96863 start.go:23] Starting application...
+Namespaces: logging
+Quantile: 0.95
+Limit margin: 1.2
++-----------+----------------------+------------+--------------------+--------------------+------------------+------------------+
+| NAMESPACE |       RESOURCE       | CONTAINER  | REQUEST CPU (SPEC) | REQUEST MEM (SPEC) | LIMIT CPU (SPEC) | LIMIT MEM (SPEC) |
++-----------+----------------------+------------+--------------------+--------------------+------------------+------------------+
+| logging   | daemonset/fluent-bit | fluent-bit | 10m (25m)          | 100Mi (100Mi)      | 100m (400m)      | 100Mi (200Mi)    |
++-----------+----------------------+------------+--------------------+--------------------+------------------+------------------+
+Total savings:
+You could save 0.32 vCPUs and 102.0 MB Memory by changing the settings
+```
+
+What these numbers mean? The idea of this tool is to find out `quantile` (default is 95%) CPU & memory real usage for single POD using Prometheus operator. We use that real usage value for specifying `requests`. Then there is another variable called `limit-margin` which is used for specifying `limits`. The default settings means that 95% of time the POD has quarantee for the resources, and 5% of time it uses burstable capacity between 95% -> 120% of POD maximum usage in history.
+
+
+#### Using namespace-selector
+
+```
+% kubectl advisory --namespace-selector maintainer=a_crowd_devops
+I0916 14:37:52.758305    5980 start.go:23] Starting application...
+Namespaces: actions-runner-system,cert-manager,default,gha,kaas-test-infra
+Quantile: 0.95
+Limit margin: 1.2
++-----------------------+-------------------------------------------------+-----------------+--------------------+--------------------+------------------+------------------+
+|       NAMESPACE       |                    RESOURCE                     |    CONTAINER    | REQUEST CPU (SPEC) | REQUEST MEM (SPEC) | LIMIT CPU (SPEC) | LIMIT MEM (SPEC) |
++-----------------------+-------------------------------------------------+-----------------+--------------------+--------------------+------------------+------------------+
+| actions-runner-system | deployment/gha-exporter                         | gha-exporter    | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 100Mi (<nil>)    |
+| actions-runner-system | deployment/ghe-runner-actions-runner-controller | manager         | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 100Mi (<nil>)    |
+| actions-runner-system | deployment/ghe-runner-actions-runner-controller | kube-rbac-proxy | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 100Mi (<nil>)    |
+| cert-manager          | deployment/cert-manager                         | cert-manager    | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 100Mi (<nil>)    |
+| cert-manager          | deployment/cert-manager-cainjector              | cert-manager    | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 200Mi (<nil>)    |
+| cert-manager          | deployment/cert-manager-webhook                 | cert-manager    | 10m (<nil>)        | 100Mi (<nil>)      | 10m (<nil>)      | 100Mi (<nil>)    |
+| kaas-test-infra       | deployment/kaas-test-infra                      | kaas-test-infra | 10m (100m)         | 100Mi (200Mi)      | 10m (400m)       | 100Mi (600Mi)    |
++-----------------------+-------------------------------------------------+-----------------+--------------------+--------------------+------------------+------------------+
+Total savings:
+You could save 0.12 vCPUs and -380.6 MB Memory by changing the settings
+```
+
+#### Using as library
+
+```
+    import "github.com/ElisaOyj/kubernetes-resource-advisor/pkg/advisor"
+
+    ...
+
+    response, err := advisor.Run(&advisor.Options{
+        Namespaces: "logging,monitoring",
+    })
+```
+
+### Motivation
+
+As SRE team we are seeing all the time Kubernetes clusters in which developers are requesting too much / too low amount of CPU or memory to PODs. In big environments this can lead to huge overhead - PODs are requesting the CPU/mem but not using it. That was motivation for this tool, by this tool we can check the real usage of CPU/memory of pod and change the requests/limits accordingly.

pkg/advisor/main.go

@@ -13,8 +13,18 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+func (o *Options) loadDefaults() {
+	if o.Quantile == "" {
+		o.Quantile = "0.95"
+	}
+	if o.LimitMargin == "" {
+		o.LimitMargin = "1.2"
+	}
+}
+
 // Run executes the resource advisor
 func Run(o *Options) (*Response, error) {
+	o.loadDefaults()
 	var err error
 	if o.Client == nil {
 		o.Client, err = newClientSet()
@@ -41,26 +51,26 @@ func Run(o *Options) (*Response, error) {
 		for _, name := range namespaces.Items {
 			strNamespace = append(strNamespace, name.Name)
 		}
-		o.Namespaces = strings.Join(strNamespace, ",")
-	} else if o.NamespaceInput != "" {
-		o.Namespaces = o.NamespaceInput
+		o.usedNamespaces = strings.Join(strNamespace, ",")
+	} else if o.Namespaces != "" {
+		o.usedNamespaces = o.Namespaces
 	} else {
 		_, namespace, err := findConfig()
 		if err != nil {
 			return nil, err
 		}
-		o.Namespaces = namespace
+		o.usedNamespaces = namespace
 	}
 
-	fmt.Printf("Namespaces: %s\n", o.Namespaces)
+	fmt.Printf("Namespaces: %s\n", o.usedNamespaces)
 	fmt.Printf("Quantile: %s\n", o.Quantile)
 	fmt.Printf("Limit margin: %s\n", o.LimitMargin)
 
 	data := [][]string{}
 
 	totalCPUSave := float64(0.00)
 	totalMemSave := float64(0.00)
-	for _, namespace := range strings.Split(o.Namespaces, ",") {
+	for _, namespace := range strings.Split(o.usedNamespaces, ",") {
 		deployments, err := o.Client.AppsV1().Deployments(namespace).List(ctx, metav1.ListOptions{})
 		if err != nil {
 			return nil, err

pkg/advisor/start.go

@@ -20,7 +20,6 @@ func init() {
 func Execute() {
 	options := &Options{}
 	flag.Lookup("logtostderr").Value.Set("true")
-	glog.Infof("Starting application...\n")
 	glog.Flush()
 	rootCmd := &cobra.Command{
 		Use:   "resource-advisor",
@@ -36,7 +35,7 @@ func Execute() {
 		},
 	}
 
-	rootCmd.Flags().StringVar(&options.NamespaceInput, "namespaces", "", "Comma separated namespaces to be scanned")
+	rootCmd.Flags().StringVar(&options.Namespaces, "namespaces", "", "Comma separated namespaces to be scanned")
 	rootCmd.Flags().StringVar(&options.NamespaceSelector, "namespace-selector", "", "Namespace selector")
 	rootCmd.Flags().StringVar(&options.Quantile, "quantile", "0.95", "Quantile to be used")
 	rootCmd.Flags().StringVar(&options.LimitMargin, "limit-margin", "1.2", "Limit margin")

pkg/advisor/types.go

@@ -9,7 +9,7 @@ import (
 
 // Options contains struct to call resource-advisor run
 type Options struct {
-	NamespaceInput    string
+	usedNamespaces    string
 	NamespaceSelector string
 	Namespaces        string
 	Quantile          string

pkg/advisor/utils.go

@@ -286,6 +286,9 @@ func (o *Options) findPods(ctx context.Context, namespace string, selector strin
 	for k, v := range totalRequestCPU {
 		scale := 10
 		value := float64Peak(v)
+		if value < 0.01 {
+			scale = 100
+		}
 		final.RequestCPU[k] = math.Ceil(value*float64(scale)) / float64(scale)
 	}
 	for k, v := range totalRequestMem {
@@ -294,6 +297,9 @@ func (o *Options) findPods(ctx context.Context, namespace string, selector strin
 	for k, v := range totalLimitCPU {
 		scale := 10
 		value := float64Peak(v)
+		if value < 0.01 {
+			scale = 100
+		}
 		final.LimitCPU[k] = math.Ceil(value*float64(scale)) / float64(scale)
 	}
 	for k, v := range totalLimitMem {