Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/coreos/etcd-operator

etcd operator creates/configures/manages etcd clusters atop Kubernetes
https://github.com/coreos/etcd-operator

etcd kubernetes operator

Last synced: 25 days ago
JSON representation

etcd operator creates/configures/manages etcd clusters atop Kubernetes

Lists

README 

        
# etcd operator



### Project status: archived



This project is no longer actively developed or maintained. The project exists here for historical reference. If you are interested in the future of the project and taking over stewardship, please contact [email protected].



### Overview



The etcd operator manages etcd clusters deployed to [Kubernetes][k8s-home] and automates tasks related to operating an etcd cluster.



- [Create and Destroy](#create-and-destroy-an-etcd-cluster)

- [Resize](#resize-an-etcd-cluster)

- [Failover](#failover)

- [Rolling upgrade](#upgrade-an-etcd-cluster)

- [Backup and Restore](#backup-and-restore-an-etcd-cluster)



There are [more spec examples](./doc/user/spec_examples.md) on setting up clusters with different configurations



Read [Best Practices](./doc/best_practices.md) for more information on how to better use etcd operator.



Read [RBAC docs](./doc/user/rbac.md) for how to setup RBAC rules for etcd operator if RBAC is in place.



Read [Developer Guide](./doc/dev/developer_guide.md) for setting up a development environment if you want to contribute.



See the [Resources and Labels](./doc/user/resource_labels.md) doc for an overview of the resources created by the etcd-operator.



## Requirements



- Kubernetes 1.8+

- etcd 3.2.13+



## Demo



## Getting started



![etcd Operator demo](https://raw.githubusercontent.com/coreos/etcd-operator/master/doc/gif/demo.gif)



### Deploy etcd operator



See [instructions on how to install/uninstall etcd operator](doc/user/install_guide.md) .



### Create and destroy an etcd cluster



```bash

$ kubectl create -f example/example-etcd-cluster.yaml

```



A 3 member etcd cluster will be created.



```bash

$ kubectl get pods

NAME                            READY     STATUS    RESTARTS   AGE

example-etcd-cluster-gxkmr9ql7z   1/1       Running   0          1m

example-etcd-cluster-m6g62x6mwc   1/1       Running   0          1m

example-etcd-cluster-rqk62l46kw   1/1       Running   0          1m

```



See [client service](doc/user/client_service.md) for how to access etcd clusters created by the operator.



If you are working with [minikube locally](https://github.com/kubernetes/minikube#minikube), create a nodePort service and test that etcd is responding:



```bash

$ kubectl create -f example/example-etcd-cluster-nodeport-service.json

$ export ETCDCTL_API=3

$ export ETCDCTL_ENDPOINTS=$(minikube service example-etcd-cluster-client-service --url)

$ etcdctl put foo bar

```



Destroy the etcd cluster:



```bash

$ kubectl delete -f example/example-etcd-cluster.yaml

```



### Resize an etcd cluster



Create an etcd cluster:



```

$ kubectl apply -f example/example-etcd-cluster.yaml

```



In `example/example-etcd-cluster.yaml` the initial cluster size is 3.

Modify the file and change `size` from 3 to 5.



```

$ cat example/example-etcd-cluster.yaml

apiVersion: "etcd.database.coreos.com/v1beta2"

kind: "EtcdCluster"

metadata:

  name: "example-etcd-cluster"

spec:

  size: 5

  version: "3.2.13"

```



Apply the size change to the cluster CR:

```

$ kubectl apply -f example/example-etcd-cluster.yaml

```

The etcd cluster will scale to 5 members (5 pods):

```

$ kubectl get pods

NAME                            READY     STATUS    RESTARTS   AGE

example-etcd-cluster-cl2gpqsmsw   1/1       Running   0          5m

example-etcd-cluster-cx2t6v8w78   1/1       Running   0          5m

example-etcd-cluster-gxkmr9ql7z   1/1       Running   0          7m

example-etcd-cluster-m6g62x6mwc   1/1       Running   0          7m

example-etcd-cluster-rqk62l46kw   1/1       Running   0          7m

```



Similarly we can decrease the size of the cluster from 5 back to 3 by changing the size field again and reapplying the change.



```

$ cat example/example-etcd-cluster.yaml

apiVersion: "etcd.database.coreos.com/v1beta2"

kind: "EtcdCluster"

metadata:

  name: "example-etcd-cluster"

spec:

  size: 3

  version: "3.2.13"

```

```

$ kubectl apply -f example/example-etcd-cluster.yaml

```



We should see that etcd cluster will eventually reduce to 3 pods:



```

$ kubectl get pods

NAME                            READY     STATUS    RESTARTS   AGE

example-etcd-cluster-cl2gpqsmsw   1/1       Running   0          6m

example-etcd-cluster-gxkmr9ql7z   1/1       Running   0          8m

example-etcd-cluster-rqk62l46kw   1/1       Running   0          9mp

```



### Failover



If the minority of etcd members crash, the etcd operator will automatically recover the failure.

Let's walk through this in the following steps.



Create an etcd cluster:



```

$ kubectl create -f example/example-etcd-cluster.yaml

```



Wait until all three members are up. Simulate a member failure by deleting a pod:



```bash

$ kubectl delete pod example-etcd-cluster-cl2gpqsmsw --now

```



The etcd operator will recover the failure by creating a new pod `example-etcd-cluster-n4h66wtjrg`:



```bash

$ kubectl get pods

NAME                            READY     STATUS    RESTARTS   AGE

example-etcd-cluster-gxkmr9ql7z   1/1       Running   0          10m

example-etcd-cluster-n4h66wtjrg   1/1       Running   0          26s

example-etcd-cluster-rqk62l46kw   1/1       Running   0          10m

```



Destroy etcd cluster:

```bash

$ kubectl delete -f example/example-etcd-cluster.yaml

```



### etcd operator recovery



Let's walk through operator recovery in the following steps.



Create an etcd cluster:



```

$ kubectl create -f example/example-etcd-cluster.yaml

```



Wait until all three members are up. Then stop the etcd operator and delete one of the etcd pods:



```bash

$ kubectl delete -f example/deployment.yaml

deployment "etcd-operator" deleted



$ kubectl delete pod example-etcd-cluster-8gttjl679c --now

pod "example-etcd-cluster-8gttjl679c" deleted

```



Next restart the etcd operator. It should recover itself and the etcd clusters it manages.



```bash

$ kubectl create -f example/deployment.yaml

deployment "etcd-operator" created



$ kubectl get pods

NAME                              READY     STATUS    RESTARTS   AGE

example-etcd-cluster-m8gk76l4ns   1/1       Running   0          3m

example-etcd-cluster-q6mff85hml   1/1       Running   0          3m

example-etcd-cluster-xnfvm7lg66   1/1       Running   0          11s

```



### Upgrade an etcd cluster



Create and have the following yaml file ready:



```

$ cat upgrade-example.yaml

apiVersion: "etcd.database.coreos.com/v1beta2"

kind: "EtcdCluster"

metadata:

  name: "example-etcd-cluster"

spec:

  size: 3

  version: "3.1.10"

  repository: "quay.io/coreos/etcd"

```



Create an etcd cluster with the version specified (3.1.10) in the yaml file:



```

$ kubectl apply -f upgrade-example.yaml

$ kubectl get pods

NAME                              READY     STATUS    RESTARTS   AGE

example-etcd-cluster-795649v9kq   1/1       Running   1          3m

example-etcd-cluster-jtp447ggnq   1/1       Running   1          4m

example-etcd-cluster-psw7sf2hhr   1/1       Running   1          4m

```



The container image version should be 3.1.10:



```

$ kubectl get pod example-etcd-cluster-795649v9kq -o yaml | grep "image:" | uniq

    image: quay.io/coreos/etcd:v3.1.10

```



Now modify the file `upgrade-example` and change the `version` from 3.1.10 to 3.2.13:



```

$ cat upgrade-example

apiVersion: "etcd.database.coreos.com/v1beta2"

kind: "EtcdCluster"

metadata:

  name: "example-etcd-cluster"

spec:

  size: 3

  version: "3.2.13"

```



Apply the version change to the cluster CR:



```

$ kubectl apply -f upgrade-example

```



Wait ~30 seconds. The container image version should be updated to v3.2.13:



```

$ kubectl get pod example-etcd-cluster-795649v9kq -o yaml | grep "image:" | uniq

    image: gcr.io/etcd-development/etcd:v3.2.13

```



Check the other two pods and you should see the same result.



### Backup and Restore an etcd cluster

> Note: The provided etcd backup/restore operators are example implementations.



Follow the [etcd backup operator walkthrough](./doc/user/walkthrough/backup-operator.md) to backup an etcd cluster.



Follow the [etcd restore operator walkthrough](./doc/user/walkthrough/restore-operator.md) to restore an etcd cluster on Kubernetes from backup.



### Manage etcd clusters in all namespaces



See [instructions on clusterwide feature](doc/user/clusterwide.md).



[k8s-home]: http://kubernetes.io