Kubernetes on GKE
=================

GKE is Google's hosted Kubernetes environment.

* Login to google cloud (change parms)::

    gcloud auth login
    gcloud beta container clusters get-credentials kubedemo-cluster --region us-east1 --project kubernetes-lighting-talk
    kubectl cluster-info


Setting up the cluster
----------------------

* Create a cluster if there's not one already. See e.g. https://github.com/caktus/gcp-web-stacks
  or https://docs.ansible.com/ansible/latest/modules/gcp_container_cluster_module.html
* Ensure your kubectl context is set to that cluster. See e.g.
  https://kubernetes.io/docs/tasks/access-application-cluster/configure-access-multiple-clusters/
  Running `kubectl cluster-info` should show the GKE cluster's information.
* Add an nginx ingress controller and letsencrypt to the cluster if not already set up.
  See https://github.com/caktus/caktus-hosting-services/blob/master/Ansible/README.rst

  You can see if a controller already exists by running `kubectl get service --namespace=ingress-nginx`.
  It'll show up as a LoadBalancer.

  You can see if Lets Encrypt is set up by running `kubectl get ClusterIssuer --all-namespaces`.
  You will probably see two objects named "letsencrypt-production" and
  "letsencrypt-staging".

Docker registry
---------------

Google provides a docker registry we can use, with some setup.  You'll need to know
the Google Cloud Platform Console Project ID.  Then you can follow these instructions
to push images to the registry that won't be public, but that your cluster will
be able to access.

* Run `gcloud auth configure-docker`. This will update your .docker/config.json
  file to tell docker to work through gcloud to authenticate you for the google
  docker registries only.
  https://cloud.google.com/container-registry/docs/advanced-authentication#gcloud_as_a_docker_credential_helper
* You should already be authenticated to Google cloud from previous steps.
* Tag your images using "us.gcr.io/PROJECTID/imagename:LABEL"
* Now you should be able to push them: `docker push us.gcr.io/PROJECTID/imagename:LABEL`.
  https://cloud.google.com/container-registry/docs/pushing-and-pulling