[CDAP-21096] Add support for startupProbe in CDAP master

[vsethi09]

CDAP-21096 Add support for startupProbe in CDAP master

Context

In addition to the rolling upgrade strategy, for high availability of APIs, startup probe need to be implemented to ensure that the CDAP service pods (eg. Appfabric) accepts requests only when the server has started.

CDAP services (eg. Appfabric) by default run on dynamic port and announces the port after the server has started. The port can be fixed for startup probe. The Command probe can be configured to check the status of system service using the URL ‘/v3/system/services//status’.

For supporting startuProbe, the CDAP services will use a fixed port defined by <service-name>.bind.port. Here is a code snippet for startup probe using the port written to the temp file:

startupProbe:
          exec:
            command:
            - sh
            - -c
            - curl -s -f -k https://localhost:<port>/v3/system/services/appfabric/status
          failureThreshold: 60
          periodSeconds: 2
          timeoutSeconds: 1

NOTE: Corresponding cdapio/cdap PR: cdapio/cdap#15859

Change Description

• Introduced StartupProbe as an optional field in the CDAPServiceSpec.
• The StartupProbe config of type corev1.Probe will be set to the container spec.
• Auto-generated:
  • api/v1alpha1/zz_generated.deepcopy.go
  • config/crd/bases/cdap.cdap.io_cdapmasters.yaml

Verification

• Unit tests: make test
• Docker image: deployed locally built docker image and edited the cdapmaster manifest to add startupProbe to appfabric spec.