k8s persistent volume / pod / service config

[gothub]

The initial plan for adding bookkeeper to k8s was to have this configuration:

• bookkeeper is run under the bookkeeper Linux user id
• bookkeeper configmaps, pods, services all run in the k8s bookkeeper namespace
• bookkeeper has it's own persistent volume that the Postgresql database is written to/persisted on

The configuration details are being tested on the k8s development cluster (i.e. docker-dev-ucsb-1.test.dataone.org). The dev cluster has one NFS share that is available and that is currently being used by the dev version of metadig-engine. All metadig-engine pods use the persistent volume (pv) and persistent volume claim (pvc) that accesses this share.

One option in this config is to share the pvc between pods in the metadig namespace and the bookkeeper namespace, but it appears that k8s doesn't support this. The supported config seems to be:

• one NFS share
• one pv
• one pvc assigned to a namespace

Another option is to have an additional NFS share that can be used by bookkeper, so set these additional NFS shares:

• the development cluster (docker-dev-ucsb-1.test.dataone.org - /data2 ?)
• the production cluster (docker-ucsb-4.dataone.org - /data2 ?)