I had to install kubectl via ansible and I spent some time to create an Ansible script following the official Kubectl linux installation instruction

This is working for me both using Ansible via command line and using Packer tool to create AWS AMIs:

---

- name: Get latest kubectl version
  uri:
    url: https://dl.k8s.io/release/stable.txt
    return_content: yes
  register: version

- name: create kubectl versioned directory
  file:
    path: /opt/kubectl-{{ version.content }}
    state: directory
  become: true

- name: Download the latest kubectl release
  uri:
    url: https://dl.k8s.io/release/{{ version.content }}/bin/linux/amd64/kubectl
    dest: /opt/kubectl-{{ version.content }}
  register: kubectl
  become: true

- name: Download the kubectl checksum
  uri:
    url: https://dl.k8s.io/release/{{ version.content }}/bin/linux/amd64/kubectl.sha256
    dest: /opt/kubectl-{{ version.content }}
  register: kubectl
  become: true

- name: Get kubectl sha256sum
  shell: sha256sum /opt/kubectl-{{ version.content }}/kubectl | cut -d " " -f1
  register: file_shasum

- set_fact:
    shasum1={{ file_shasum.stdout }}

- debug: var=shasum1
  run_once: true

- name: get sha256sum value from file
  command: cat /opt/kubectl-{{ version.content }}/kubectl.sha256
  register: downloaded_shasum

- set_fact:
    shasum2={{ downloaded_shasum.stdout }}

- debug: var=shasum2
  run_once: true

- name: Assert that the kubectl binary is OK
  assert:
    that:
      - file_shasum.stdout == downloaded_shasum.stdout
    fail_msg: "Shasum does not correspond"
    success_msg: "kubectl shasum verified: ok"

- name: Change kubectl file permission
  file:
    path: "/opt/kubectl-{{ version.content }}/kubectl"
    mode: '0755'
  become: true

- name: create a symlink to kubectl
  file:
    src: "/opt/kubectl-{{ version.content }}/kubectl"
    dest: "/usr/bin/kubectl"
    state: link
  become: true

Any comment appreciated.

The best way to do this would be to use ansible kubernetes.core collection

An example with file:

- name: Create a Deployment by reading the definition from a local file
  kubernetes.core.k8s:
    state: present
    src: /testing/deployment.yml

So, you could loop from different folders containing the yaml definitions for your objects with state: present

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