etcd

Etcd Service

This project provides an Etcd service that can run inside of Kubernetes.

There are two parts:

• An in-cluster discovery service (deis-etcd-discovery)
• A dynamic etcd cluster (deis-etcd)

Both parts run inside of any Kubernetes 1.0+ cluster. No modifications need to be made to Kubernetes.

Usage

Currently, this project is under heavy development. Eventually, installing will be a matter of running a few kubectl commands, but right now it needs a little more.

Assuming you have kubectl, docker, a Docker registry, and go 1.5.1 or greater, you can do this:

Get your dev environment ready:

$ go get github.com/Masterminds/glide
$ $GOPATH/bin/glide install
$ export DEV_REGISTRY=your.docker.registry.url:port

Start the services and mount the secrets volumes:

$ make kube-service

Build it all, push it to Docker, and then load it into Kubernetes:

$ make all

You can check on things using kubectl:

$ kubectl get pod

Note that if your registry is insecure, you need to configure Kubernetes' Docker instances to allow the --insecure-registry.

Notes

1. Right now, the discovery token is hard-coded into the secret. Feel free to change it to meet your needs.
2. Persistent storage for Etcd is not yet implemented, though it will be in short order.
3. The cluster is designed to be relatively self-healing. When a Pod dies, the pod that is spawned in its place will attempt to clean up mess.
4. The discovery instance of etcd is also used for an additional heartbeats layer, so it must stay running in order to help a failed cluster rebuild.
5. This project builds one Docker image that has two executable paths. If it is started with the /usr/local/bin/boot, it will be an etcd cluster member. If it is started with /usr/local/bin/discovery it will come up as a discovery service.

Finally, this distribution will not work outside of Kubernetes unless you do a lot of environment altering. It uses Kubernetes service discovery environment variables, secrets volume mounts, and the Kubernetes API server.