如何在pod副本中运行etcd集群?

I have a pod/service running an application that consumes etcd as a synchronization system and datastore. I want to run etcd within the pod, such that all of the replicas form a coherent cluster. In other words, so the application in replica #1 can write "foo" to localhost:4001/v2/keys/my_key and then replica #2 can then read localhost:4001/v2/keys/my_key and get "foo" as a result.

我有一个pod/服务运行一个应用程序，它使用etcd作为同步系统和数据存储。我想在pod中运行etcd，这样所有的副本都形成一个连贯的集群。换句话说，因此副本#1中的应用程序可以将“foo”写入localhost:4001/v2/keys/my_key，然后第二个副本#2可以读取localhost:4001/v2/keys/my_key，然后得到“foo”。

It's not clear how this can be done, since pod replicas are not individually addressable. I could in theory create an "etcd" service exposing the cluster ports, but any requests would round-robin to all the replicas so the individual etcd nodes would not be able to find each other.

目前尚不清楚这是如何实现的，因为pod副本不是单独可寻址的。理论上，我可以创建一个暴露集群端口的“etcd”服务，但是任何请求都将对所有副本进行循环，这样每个etcd节点就无法找到彼此。

Am I approaching this problem the correct way?

我处理这个问题的方法正确吗?

3 个解决方案

#1

You can deploy etcd on kubernetes using an Operator (from the extensions/v1beta1) and the quay.io/coreos/etcd-operator image.

您可以使用操作符(来自扩展名/v1beta1)和码头在kubernetes上部署etcd。io / coreos etcd-operator形象。

An example deployment with a cluster size of 3 looks like this:

一个集群大小为3的部署示例如下:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: etcd-operator
spec:
  replicas: 1
  template:
    metadata:
      name: etcd-operator
      labels:
        app: etcd
        component: operator
    spec:
      containers:
      - name: etcd-operator
        image: quay.io/coreos/etcd-operator:v0.3.0
        env:
        - name: MY_POD_NAMESPACE
          valueFrom: { fieldRef: { fieldPath: metadata.namespace } }
        - name: MY_POD_NAME
          valueFrom: { fieldRef: { fieldPath: metadata.name } }

---

apiVersion: etcd.coreos.com/v1beta1
kind: Cluster
metadata:
  name: etcd-cluster
  labels:
    app: etcd
    component: cluster
spec:
  size: 3
  version: "3.1.8"

Please be aware of the beta status of this project. However according to the maintainers the operator is now stable. I have deployed the configuration above successfully but I didn't run any of this in production.

请注意这个项目的beta状态。但是根据维护人员的说法，该操作现在是稳定的。我已经成功地部署了上面的配置，但是我没有在生产中运行这些配置。

The operator code is available on github. You can find additional documentation there.

操作符代码可以在github上找到。您可以在那里找到其他文档。

#2

There's a pretty good example of a three node etcd cluster here: https://github.com/coreos/etcd/tree/master/hack/kubernetes-deploy

这里有一个很好的三个节点etcd集群示例:https://github.com/coreos/etcd/tree/master/hack/kubernetes-deploy

They make use of separate rc's and services for each replica as a workaround until nominal services are added.

它们利用每个副本的独立rc和服务作为解决方案，直到添加名义上的服务。

#3

I added your question to kubernetes/kubernetes#5017

我把你的问题加到了kubernetes/kubernetes#5017

If someone knows the answer, they will hopefully post it there.

如果有人知道答案，他们会希望把它贴在那里。

I think it may require the "nominal services" feature (kubernetes/kubernetes#260) which is not implemented yet, but I'm not sure.

我认为它可能需要“名义服务”功能(kubernetes/kubernetes#260)，但我不确定。

#1