Add service account template to graphql-engine

[seth-acuitymd]

Adds a service account template for the graphql-engine chart. This template will be rendered (default name: graphql-engine) when serviceAccount.enabled is set to true, also allows adding desired annotations or labels to the service account.

Fixes #18

[seth-acuitymd]

Just some tests with helm template .

• setting to enabled: false - nothing happens (as expected)
• setting to enabled: true with nothing else set:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: graphql-engine
  namespace: default

---

• setting to enabled: true with a label and annotation:

# values
serviceAccount:
  enabled: true
  name: ""
  annotations:
    test: "test-1"
    test2: "test-2"
  labels: 
    test-label: "test-label"

# helm template output
apiVersion: v1
kind: ServiceAccount
metadata:
  name: graphql-engine
  namespace: default
  annotations:
    test: test-1
    test2: test-2
  labels:
    test-label: test-label

---

• setting to enabled: true just a custom service account name:

# values
serviceAccount:
  enabled: true
  name: "thisisatestserviceaccountname"
  annotations: {}
  labels: {}

# helm template output
apiVersion: v1
kind: ServiceAccount
metadata:
  name: thisisatestserviceaccountname
  namespace: default

[hgiasac]

IMO we just set graphql-engine directly to this name field. Users won't need to explore the helm source template to know the default service account name

[seth-acuitymd]

That works! I wasn't sure if there was a preference!

[seth-acuitymd]

@hgiasac was that a request or suggestion? Shall I push that as a change?

[hgiasac]

LGTM. Thanks for contributing