Introduced the capability to change the list of monitors in the existing Ceph PV

Author: Vadim Lazovsky

2020/04-etcdhelper/README.md

@@ -49,6 +49,11 @@ go build -o etcdhelper etcdhelper.go
 ./etcdhelper -cacert /etc/kubernetes/pki/etcd/ca.crt -cert /etc/kubernetes/pki/etcd/server.crt -key /etc/kubernetes/pki/etcd/server.key -endpoint https://127.0.0.1:2379 change-pod-cidr 10.55.0.0/16
 ```
 
+### Change Ceph PV monitors list
+```shell
+./etcdhelper -cacert /etc/kubernetes/pki/etcd/ca.crt -cert /etc/kubernetes/pki/etcd/server.crt -key /etc/kubernetes/pki/etcd/server.key -endpoint https://127.0.0.1:2379 change-monitors-list pvc-d748b019-52be-4c0c-a928-44503ccd94ac 10.0.1.1:6789,10.0.1.2:6789,10.0.1.3:6789
+```
+
 # Status
 
 This enhanced version of etcdhelper is **PoC (proof of concept)**. Use it on your own risk.

2020/04-etcdhelper/etcdhelper.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"os"
 	"regexp"
+	"strings"
 	"time"
 
 	"go.etcd.io/etcd/clientv3"
@@ -58,6 +59,21 @@ func main() {
 		}
 		os.Exit(1)
 	}
+	if flag.Arg(0) == "change-monitors-list" {
+		if flag.Arg(1) == "" || flag.Arg(2) == "" {
+			fmt.Fprint(os.Stderr, "ERROR: you have to specify both: PV name and list of comma-separated monitor IP-addresses\n")
+			os.Exit(1)
+		}
+		if !regexp.MustCompile(`^pvc-[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$`).MatchString(flag.Arg(1)) {
+			fmt.Fprint(os.Stderr, "ERROR: invalid PV name. Ex: pvc-dd3afe18-1bae-411c-9a1d-df129847cb62")
+			os.Exit(1)
+		}
+		if !regexp.MustCompile(`^(((\d+\.){3}\d+):\d+,?)+$`).MatchString(flag.Arg(2)) {
+			fmt.Fprint(os.Stderr, "ERROR: invalid IP-address list. Ex: 1.1.1.1:6789,2.2.2.2:6789,3.3.3.3:6789\n")
+			os.Exit(1)
+		}
+	}
+
 	action := flag.Arg(0)
 	key := ""
 	if flag.NArg() > 1 {
@@ -100,6 +116,8 @@ func main() {
 		err = changeServiceCIDR(client, flag.Arg(1))
 	case "change-pod-cidr":
 		err = changePodCIDR(client, flag.Arg(1))
+	case "change-monitors-list":
+		err = changeMonitorsList(client, flag.Arg(1), flag.Arg(2))
 	case "dump":
 		err = dump(client)
 	default:
@@ -194,6 +212,35 @@ func changePodCIDR(client *clientv3.Client, cidr string) error {
 	return nil
 }
 
+func changeMonitorsList(client *clientv3.Client, pvName, list string) error {
+	decoder := scheme.Codecs.UniversalDeserializer()
+
+	pvKey := fmt.Sprintf("/registry/persistentvolumes/%s", pvName)
+
+	resp, err := clientv3.NewKV(client).Get(context.Background(), pvKey)
+	if err != nil {
+		fmt.Printf("get key %s %s\n", pvKey, err)
+	}
+
+	obj, _, _ := decoder.Decode(resp.Kvs[0].Value, nil, nil)
+
+	pv := obj.(*v1.PersistentVolume)
+
+	monitors := strings.Split(strings.Trim(list, ","), ",")
+	pv.Spec.RBD.CephMonitors = monitors
+
+	protoSerializer := protobuf.NewSerializer(scheme.Scheme, scheme.Scheme)
+	newObj := new(bytes.Buffer)
+	protoSerializer.Encode(obj, newObj)
+
+	_, err = clientv3.NewKV(client).Put(context.Background(), pvKey, newObj.String())
+	if err != nil {
+		fmt.Printf("put to key %s %s\n", pvKey, err)
+	}
+
+	return nil
+}
+
 func listKeys(client *clientv3.Client, key string) ([]string, error) {
 	var resp *clientv3.GetResponse
 	var err error

2020/04-etcdhelper/go.mod

@@ -0,0 +1,15 @@
+module etcdhelper
+
+go 1.14
+
+require (
+	github.com/coreos/etcd v3.3.20+incompatible // indirect
+	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf // indirect
+	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
+	github.com/gardener/machine-controller-manager v0.29.0
+	go.etcd.io/etcd v3.3.20+incompatible
+	go.uber.org/zap v1.15.0 // indirect
+	k8s.io/api v0.17.2
+	k8s.io/apimachinery v0.17.2
+	k8s.io/kubectl v0.17.2
+)