Create one Kubernetes Service per job

[viovanov]

• Change helm charts so they generate one service per job
• Remove the headless tag from fissile
• Exposed ports have to be moved to the job section
• Update fissile doc
• Update SCF/UAA

Use the following rule to determine the service name (which in turn determines the hostname):

<role-name>-<job-name>

Ports must be exposed like this:

roles:
- name: nats
  jobs:
  - name: nats
    properties:
      bosh_containerization:
        ports:
        - name: nats
          protocol: TCP
          internal: 4222
        - name: nats-routes
          protocol: TCP
          internal: 4223

[alexjh]

Remove the headless tag from fissile

Can you elaborate on why this is happening?

It looks like we could create up to three services per role right now:

https://github.com/SUSE/fissile/blob/711088fd60db22ace2ad33bd887c91e6f8d4df51/kube/service.go#L16-L36

If the headless tag goes away, does that mean we'll always create three services for each StatefulSet, since the headless tag would never be set?

Edit: Three services for each public role, two for non-public.

[alexjh]

Also, it looks like we could determine if a service should be public or not with the public: true setting in the port config.

https://github.com/SUSE/scf/blob/b3be225282389bdce24dec05e351f6b697fe5d89/container-host-files/etc/scf/config/role-manifest.yml#L487-L490

[alexjh]

Right now in our helm templates we have a StatefulSet per role, and that is linked to service via a serviceName called <role-name>-set.

spec: 
  podManagementPolicy: "OrderedReady"
  replicas: {{ if and .Values.config.HA (eq (int .Values.sizing.api.count) 1) -}} 2 {{- else -}} {{ .Values.sizing.api.count }} {{- end }}
  serviceName: "api-set"

I don't see a way to link the newly named service <role-name>-<job-name> to the StatefulSet.

For example, with our new database role, we have two jobs inside it: mysql and mysql-proxy. What service should the database StatefulSet refer to?

[alexjh]

@viovanov

I've been struggling to find a fix for addressing individual pods with this setup.

We need to access pods for things like this: https://github.com/cloudfoundry/cf-syslog-drain-release/blob/develop/jobs/scheduler/templates/environment.sh.erb#L8

According to the Kube docs (and my testing), in order to get a hostname for a pod, the StatefulSet's serviceName must match a service.

Also note that a service must have ports associated with it. I initially hoped I could make a dummy service with just the instance group name, but I need ports to go along with it.

What I'm looking at now is collecting all of the ports for the jobs inside the instance group, and making a service out of that. If you have any other ideas, please let me know.