RethinkDB Cluster on Kubernetes ============================== Setting up a [rethinkdb](http://rethinkdb.com/) cluster on [kubernetes](http://kubernetes.io) **Features** * Auto configuration cluster by querying info from k8s * Simple Quick start ----------- **Step 1** antmanler/rethinkdb will discover peer using endpoints provided by kubernetes_ro service, so first create a service so the following pod can query its endpoint ```shell kubectl create -f driver-service.yaml ``` check out: ```shell $kubectl get se NAME LABELS SELECTOR IP PORT rethinkdb-driver db=influxdb db=rethinkdb 10.241.105.47 28015 ``` **Step 2** start fist server in cluster ```shell kubectl create -f rc.yaml ``` Actually, you can start servers as many as you want at one time, just modify the `replicas` in `rc.ymal` check out again: ```shell $kubectl get po POD IP CONTAINER(S) IMAGE(S) HOST LABELS STATUS 99f6d361-abd6-11e4-a1ea-001c426dbc28 10.240.2.68 rethinkdb rethinkdb:1.16.0 10.245.2.2/ db=rethinkdb,role=replicas Running ``` **Done!** --- Scale ----- You can scale up you cluster using `kubectl resize`, and new pod will join to exsits cluster automatically, for example ```shell $kubectl resize rc rethinkdb-rc-1.16.0 --replicas=3 resized $kubectl get po POD IP CONTAINER(S) IMAGE(S) HOST LABELS STATUS 99f6d361-abd6-11e4-a1ea-001c426dbc28 10.240.2.68 rethinkdb rethinkdb:1.16.0 10.245.2.2/ db=rethinkdb,role=replicas Running d10182b5-abd6-11e4-a1ea-001c426dbc28 10.240.26.14 rethinkdb rethinkdb:1.16.0 10.245.2.4/ db=rethinkdb,role=replicas Running d101c1a4-abd6-11e4-a1ea-001c426dbc28 10.240.11.14 rethinkdb rethinkdb:1.16.0 10.245.2.3/ db=rethinkdb,role=replicas Running ``` Admin ----- You need a separate pod (which labled as role:admin) to access Web Admin UI ```shell kubectl create -f admin-pod.yaml kubectl create -f admin-service.yaml ``` find the service ```shell $kubectl get se NAME LABELS SELECTOR IP PORT rethinkdb-admin db=influxdb db=rethinkdb,role=admin 10.241.220.209 8080 rethinkdb-driver db=influxdb db=rethinkdb 10.241.105.47 28015 ``` open a web browser and access to *http://10.241.220.209:8080* to manage you cluster **Why not just using pods in replicas?** This is because kube-proxy will act as a load balancer and send your traffic to different server, since the ui is not stateless when playing with Web Admin UI will cause `Connection not open on server` error. - - - **BTW** * All services and pods are placed under namespace `rethinkdb`. * `gen_pod.sh` is using to generate pod templates for my local cluster, the generated pods which is using `nodeSelector` to force k8s to schedule containers to my designate nodes, for I need to access persistent data on my host dirs. * see [antmanler/rethinkdb-k8s](https://github.com/antmanler/rethinkdb-k8s) for detail