[web/task split] add topology constraints for each deployment

[thedoubl3j]

SUMMARY

Fixes a portion of #1182.

Add the ability for users to add topology spread constraints across the web and task deployments or set a specific one for the whole deployment

ISSUE TYPE

• New or Enhanced Feature

TESTING

Expected results will be similar in how the previous iterations of adding these types of features go in that there is the default topology_spread_constraints key which will apply to the whole deployment and then can be overwritten by web_topology_spread_constraints or task_topology_spread_constraints for their respective deployments

• test case 1: specify default behavior of apply topology_spread_constraints for the whole deployment
  CRD Change

 topology_spread_constraints: |
   - maxSkew: 100
     topologyKey: "topology.kubernetes.io/zone"
     whenUnsatisfiable: "ScheduleAnyway"
     labelSelector:
       matchLabels:
         app.kubernetes.io/part-of: 'awx'

result is toplogySpreadConstraints is applied to both deployments and set the same

➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-web 
...
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/part-of: awx
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway
➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-task 
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/part-of: awx
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway

• test case 2: apply a web_topology_spread_constraints to change the web deployment but leave the task deployment the same as above in tc1
  CRD Change

  topology_spread_constraints: |
    - maxSkew: 100
      topologyKey: "topology.kubernetes.io/zone"
      whenUnsatisfiable: "ScheduleAnyway"
      labelSelector:
        matchLabels:
          app.kubernetes.io/part-of: 'awx'
  web_topology_spread_constraints: |
    - maxSkew: 100
      topologyKey: "topology.kubernetes.io/zone"
      whenUnsatisfiable: "ScheduleAnyway"
      labelSelector:
        matchLabels:
          app.kubernetes.io/name: 'awx-web'

result was awx-web deployment changed but task stayed the same

➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-web  
terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/name: awx-web
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway
➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-task
      terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/part-of: awx
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway

• test case 3: apply a task_topology_spread_constraints to change the task deployment while leaving the web deployment constraint in place (aka same as tc2)
  CRD Change

  task_topology_spread_constraints: |
    - maxSkew: 100
      topologyKey: "topology.kubernetes.io/zone"
      whenUnsatisfiable: "ScheduleAnyway"
      labelSelector:
        matchLabels:
          app.kubernetes.io/name: 'awx-task'
  web_topology_spread_constraints: |
    - maxSkew: 100
      topologyKey: "topology.kubernetes.io/zone"
      whenUnsatisfiable: "ScheduleAnyway"
      labelSelector:
        matchLabels:
          app.kubernetes.io/name: 'awx-web'

result is the task deployment's previous spread constraint set in tc1 is overwritten with the new constraint and web remains the same

➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-task
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/name: awx-task
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway
➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-web
      serviceAccount: awx
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30
      topologySpreadConstraints:
      - labelSelector:
          matchLabels:
            app.kubernetes.io/name: awx-web
        maxSkew: 100
        topologyKey: topology.kubernetes.io/zone
        whenUnsatisfiable: ScheduleAnyway

• test case 4: remove all constraints and reset back to default behavior
  CRD Change
  remove all previous topology_spread_constraints
  result is default behavior

➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-web
      securityContext: {}
      serviceAccount: awx
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30
      volumes:
➜  awx-operator git:(add_topology_spread) kubectl edit deployment awx-task
      schedulerName: default-scheduler
      securityContext: {}
      serviceAccount: awx
      serviceAccountName: awx
      terminationGracePeriodSeconds: 30