awx-operator/docs/user-guide/advanced-configuration/assigning-awx-pods-to-specific-nodes.md

Assigning AWX pods to specific nodes

You can constrain the AWX pods created by the operator to run on a certain subset of nodes. node_selector and postgres_selector constrains the AWX pods to run only on the nodes that match all the specified key/value pairs. tolerations and postgres_tolerations allow the AWX pods to be scheduled onto nodes with matching taints. The ability to specify topologySpreadConstraints is also allowed through topology_spread_constraints If you want to use affinity rules for your AWX pod you can use the affinity option.

If you want to constrain the web and task pods individually, you can do so by specifying the deployment type before the specific setting. For example, specifying task_tolerations will allow the AWX task pod to be scheduled onto nodes with matching taints.

Name	Description	Default
postgres_image	Path of the image to pull	quay.io/sclorg/postgresql-15-c9s
postgres_image_version	Image version to pull	latest
node_selector	AWX pods' nodeSelector	''
web_node_selector	AWX web pods' nodeSelector	''
task_node_selector	AWX task pods' nodeSelector	''
topology_spread_constraints	AWX pods' topologySpreadConstraints	''
web_topology_spread_constraints	AWX web pods' topologySpreadConstraints	''
task_topology_spread_constraints	AWX task pods' topologySpreadConstraints	''
affinity	AWX pods' affinity rules	''
web_affinity	AWX web pods' affinity rules	''
task_affinity	AWX task pods' affinity rules	''
tolerations	AWX pods' tolerations	''
web_tolerations	AWX web pods' tolerations	''
task_tolerations	AWX task pods' tolerations	''
annotations	AWX pods' annotations	''
postgres_selector	Postgres pods' nodeSelector	''
postgres_tolerations	Postgres pods' tolerations	''

Example of customization could be:

---
spec:
  ...
  node_selector: |
    disktype: ssd
    kubernetes.io/arch: amd64
    kubernetes.io/os: linux
  topology_spread_constraints: |
    - maxSkew: 100
      topologyKey: "topology.kubernetes.io/zone"
      whenUnsatisfiable: "ScheduleAnyway"
      labelSelector:
        matchLabels:
          app.kubernetes.io/name: "<resourcename>"
  tolerations: |
    - key: "dedicated"
      operator: "Equal"
      value: "AWX"
      effect: "NoSchedule"
  task_tolerations: |
    - key: "dedicated"
      operator: "Equal"
      value: "AWX_task"
      effect: "NoSchedule"
  postgres_selector: |
    disktype: ssd
    kubernetes.io/arch: amd64
    kubernetes.io/os: linux
  postgres_tolerations: |
    - key: "dedicated"
      operator: "Equal"
      value: "AWX"
      effect: "NoSchedule"
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        preference:
          matchExpressions:
          - key: another-node-label-key
            operator: In
            values:
            - another-node-label-value
            - another-node-label-value
    podAntiAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 100
        podAffinityTerm:
          labelSelector:
            matchExpressions:
            - key: security
              operator: In
              values:
              - S2
          topologyKey: topology.kubernetes.io/zone

Special Note on DB-Migration Job Scheduling

For the db-migration job, which applies database migrations at cluster startup, you can specify scheduling settings using the task_* configurations such as task_node_selector, task_tolerations, etc.
If these task-specific settings are not defined, the job will automatically use the global AWX configurations like node_selector and tolerations.