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
- Right now, the discovery token is hard-coded into the secret. Feel free to change it to meet your needs.
- Persistent storage for Etcd is not yet implemented, though it will be in short order.
- 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.
- 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.
- 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/discoveryit 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.