42-kubernetes-cloud-provider.md

Kubernetes with a cloud provider

Warning

This strategy was not tested on an actual cluster yet, so it is highly experimental at this point.

If you run kubectl from your computer to manage the Kubernetes cluster, you will need to install it. You can check the guide for Single computer, and ignore the minikube installation.

You have to configure access to the cluster, and since that depends on the cloud provider, I will leave that to you. Please remember that all commands will assume that you are connecting to the cluster, which might involve additional flags to pass your credentials.

Create a namespace for asreview things

The configuration files use the namespace asreview-cloud by default, so if you want to change it, you need to change in the file below and all other places that have # namespace: asreview-cloud.

kubectl apply -f asreview-cloud-namespace.yml

Create a volume

To share data between the worker and taskers, and to keep that data after using it, we need to create a volume. The volume is necessary to hold the data, scripts, and the output, for instance.

If you have some volume provider that accepts ReadWriteMany, use that. Otherwise, we show below how to set up a NFS server using Kubernetes resources, and then how to use that server as volume for your pods.

The file storage-nfs.yml will run an NFS server inside one of the nodes. Simple run

kubectl apply -f storage-nfs.yml

Then, run

kubectl -n asreview-cloud get services

You should see something like

NAME             TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                        AGE
...
nfs-service      ClusterIP   NFS_SERVICE_IP   <none>        2049/TCP,20048/TCP,111/TCP     82m
...

Copy the NFS_SERVICE_IP. Then, uncomment the first 3 lines of the volumes sections of files worker.yml and tasker.yml (end of the file). For this case, it should look like

volumes:
  - name: asreview-storage
    nfs:
      server: NFS_SERVICE_IP
      path: "/"