How to setup ansible playbook that is able to execute kubectl (kubernetes) commands
I would like to utilise kubectl connection plugin: https://docs.ansible.com/ansible/latest/plugins/connection/kubectl.html but having struggle to figure out how to actually do that.
The fine manual describes how one uses connection plugins, and while it is possible to use in in tasks, that is unlikely to make any sense unless your inventory started with Pods.
The way I have seen that connection used is to start by identifying the Pods against which you might want to take action, and then run a playbook against a unique group for that purpose:
- hosts: all tasks: - set_fact: # this is *just an example for brevity* # in reality you would use `k8s:` or `kubectl get -o name pods -l my-selector=my-value` to get the pod names pod_names: - nginx-12345 - nginx-3456 - add_host: name: '{{ item }}' groups: - my-pods with_items: '{{ pod_names }}'- hosts: my-pods connection: kubectl tasks: # and now you are off to the races - command: ps -ef # watch out if the Pod doesn't have a working python installed # as you will have to use raw: instead # (and, of course, disable "gather_facts: no") - raw: ps -ef
First install k8s collections
ansible-galaxy collection install community.kubernetes
and here is play-book, it will sort all pods and run a command in every pod
---- hosts: localhost vars_files: - vars/main.yaml collections: - community.kubernetes tasks: - name: Get the pods in the specific namespace k8s_info: kubeconfig: '{{ k8s_kubeconfig }}' kind: Pod namespace: test register: pod_list - name: Print pod names debug: msg: "pod_list: {{ pod_list | json_query('resources[*].status.podIP') }} " - set_fact: pod_names: "{{pod_list|json_query('resources[*].metadata.name')}}" - k8s_exec: kubeconfig: '{{ k8s_kubeconfig }}' namespace: "{{ namespace }}" pod: "{{ item.metadata.name }}" command: apt update with_items: "{{ pod_list.resources }}" register: exec loop_control: label: "{{ item.metadata.name }}"
Maybe you can use like this...
- shell: | kubectl exec -i -n {{ namespace }} {{ pod_name }} -- bash -c 'clickhouse-client --query "INSERT INTO customer FORMAT CSV" --user=test --password=test < /mnt/azure/azure/test/test.tbl'