1+ package cmd
2+
3+ import (
4+ "context"
5+ "fmt"
6+ "strings"
7+
8+ "github.com/spf13/cobra"
9+
10+ //appsv1 "k8s.io/api/apps/v1"
11+ corev1 "k8s.io/api/core/v1"
12+ metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
13+ "k8s.io/client-go/kubernetes"
14+ "k8s.io/client-go/tools/clientcmd"
15+ )
16+
17+ // scaleCmd represents the scale command
18+ var scaleCmd = & cobra.Command {
19+ Use : "scale [PVC]" ,
20+ Short : "Finds any Pods accessing the given PVC and sacles them down through their Deployments/ReplicationSets" ,
21+ Long : `Depending on the data that is written to the Persistent Volume Claim, it can be required to stop the Pod
22+ writing to it first. An example is a database, which keeps data in-memory. A relyable way to flush this
23+ data to disc is to shut the application down.
24+
25+ For other use-cases like static asset hosting, this might not be required.` ,
26+ Args : cobra .MinimumNArgs (1 ),
27+ Run : func (cmd * cobra.Command , args []string ) {
28+ fmt .Printf ("Attempting to scale down anything that uses %s\n " , args [0 ])
29+
30+ config , err := clientcmd .BuildConfigFromFlags ("" , "/Users/lukasknuth/k3sup/kubeconfig" )
31+ if err != nil {
32+ panic (err .Error ())
33+ }
34+
35+ clientset , err := kubernetes .NewForConfig (config )
36+ if err != nil {
37+ panic (err .Error ())
38+ }
39+
40+ // todo add namespace flag!
41+ // todo use another "context"!?
42+
43+ // ######
44+ pods , err := clientset .CoreV1 ().Pods ("infrastructure" ).List (context .TODO (), metav1.ListOptions {})
45+ if err != nil {
46+ panic (err .Error ())
47+ }
48+
49+ filtered := filterMountingPods (pods .Items , args [0 ])
50+ tree := make ([]metav1.ObjectMeta , 0 )
51+ for _ , pod := range filtered {
52+ fmt .Printf ("Mounted by %s: %s\n " , "Pod" , pod .Name )
53+ options := RequestOptions {Namespace : "infrastructure" , Context : context .TODO (), Clientset : clientset }
54+ tree , err = dependencyTree (pod .ObjectMeta , tree , 1 , & options )
55+ if err != nil {
56+ panic (err .Error ())
57+ }
58+ }
59+ fmt .Printf ("Should scale %d resources\n " , len (tree ))
60+ for _ , res := range tree {
61+ fmt .Printf (" %s\n " , res .Name )
62+ }
63+ },
64+ }
65+
66+ func init () {
67+ rootCmd .AddCommand (scaleCmd )
68+
69+ // Here you will define your flags and configuration settings.
70+
71+ // Cobra supports Persistent Flags which will work for this command
72+ // and all subcommands, e.g.:
73+ // scaleCmd.PersistentFlags().String("foo", "", "A help for foo")
74+
75+ // Cobra supports local flags which will only run when this command
76+ // is called directly, e.g.:
77+ //scaleCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
78+ }
79+
80+ func filterMountingPods (pods []corev1.Pod , pvcName string ) []corev1.Pod {
81+ var filtered []corev1.Pod
82+ for _ , pod := range pods {
83+ for _ , vol := range pod .Spec .Volumes { // todo also filter by state + filter yourself (by hostname)
84+ if vol .VolumeSource .PersistentVolumeClaim != nil && vol .VolumeSource .PersistentVolumeClaim .ClaimName == pvcName {
85+ filtered = append (filtered , pod )
86+ }
87+ }
88+ }
89+ return filtered
90+ }
91+
92+ type RequestOptions struct {
93+ Clientset * kubernetes.Clientset
94+ Context context.Context
95+ Namespace string
96+ }
97+
98+ func dependencyTree (resource metav1.ObjectMeta , toScale []metav1.ObjectMeta , level int , options * RequestOptions ) ([]metav1.ObjectMeta , error ) {
99+ if len (resource .OwnerReferences ) > 0 {
100+ for _ , owner := range resource .OwnerReferences {
101+ ownerRes , err := fetchResource (& owner , options )
102+ if err != nil {
103+ return nil , err
104+ } else if ownerRes != nil {
105+ fmt .Printf ("%s-> %s (%s)\n " , strings .Repeat (" " , level ), ownerRes .Name , "todo" ) // todo use wrappers instead?
106+ toScale , err = dependencyTree (* ownerRes , toScale , level + 1 , options )
107+ if err != nil {
108+ return nil , err
109+ }
110+ } else {
111+ fmt .Printf ("%s-> Unsupported owner %s of type %s\n " , strings .Repeat (" " , level ), owner .Name , owner .Kind )
112+ }
113+ }
114+ return toScale , nil
115+ } else {
116+ return append (toScale , resource ), nil
117+ }
118+ }
119+
120+ func fetchResource (ref * metav1.OwnerReference , options * RequestOptions ) (* metav1.ObjectMeta , error ) {
121+ switch ref .Kind {
122+ case "ReplicaSet" :
123+ rs , err := options .Clientset .AppsV1 ().ReplicaSets (options .Namespace ).Get (options .Context , ref .Name , metav1.GetOptions {})
124+ if err != nil {
125+ return nil , err
126+ } else {
127+ return & rs .ObjectMeta , nil
128+ }
129+ case "Deployment" :
130+ d , err := options .Clientset .AppsV1 ().Deployments (options .Namespace ).Get (options .Context , ref .Name , metav1.GetOptions {})
131+ if err != nil {
132+ return nil , err
133+ } else {
134+ return & d .ObjectMeta , nil
135+ }
136+ case "Job" :
137+ fallthrough
138+ case "CronJob" :
139+ fallthrough
140+ case "DaemonSet" :
141+ fallthrough
142+ case "StatefulSet" :
143+ fallthrough
144+ default :
145+ return nil , nil
146+ }
147+ }
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