Execute command in Kubernetes Deployment with Ansible

k8s-deploy-exec.yml

---
# This playbook queries Kubernetes to find a pod within a playbook and then
# runs a commnad within one of those pods. This is essentially the Ansible
# way to perform the following kubectl command:
#
#   kubectl exec -n keycloak deploy/postgres -- psql -U postgres -c '\l'
#
- hosts: localhost
  tasks:

  - name: Get the Postgres deployment
    kubernetes.core.k8s_info: 
      kind: Deployment
      namespace: keycloak
      name: postgres
    register: postgres_deploy
    failed_when: postgres_deploy.resources | length != 1

  - name: Get the pods in the Postgres deployment using the selector from the
      deployment
    kubernetes.core.k8s_info: 
      kind: Pod
      namespace: keycloak
      label_selectors: '{{ postgres_deploy.resources[0].spec.selector.matchLabels | list }}'
    register: postgres_pods
    failed_when: postgres_pods.resources | length != 1

  - name: Print the postgres pod names
    ansible.builtin.debug:
      var: postgres_pods.resources | map(attribute='metadata.name')

  - name: Execute a command in one of the pods
    kubernetes.core.k8s_exec: 
      namespace: keycloak
      pod: '{{ postgres_pods.resources[0].metadata.name }}'
      command: psql -U postgres -c '\l'
    register: cmd_result

  - name: Print the command output
    ansible.builtin.debug:
      var: cmd_result.stdout_lines