Executeing a command in Pod of Kubernetes or Openshift

 I am working on an application which is hosted in kubernetes and currently it does not support any kind of API. The only way to automate the workflow what we are trying to achieve is to login into one of the pod of that application and run a commds which will run the conciliation 

 So i have written a ansible playbook and to keep it simple i have installed kubernetes python library on the target machine using which i am accessing the kubernetes application  

pip install kubernetes

Once done i have wrote a ansible playbook the config are loaded from ~/.kube/config file on that server and below is the sample playbook. here am executing a sample play which is printing the nginx pod host name but it can be replace with the actual command we want to run

- name: Execute command inside a Kubernetes pod selected by label

hosts: all

gather_facts: no

collections:

- kubernetes.core

vars:

namespace: "default" ## add namespace here

label_selector: "app=nginx" # add lable selector here

container_name: "" # optional — leave empty to use default container

exec_command: "/usr/bin/hostname" # command to run inside the container

tasks:

- name: Get pods matching label selector

kubernetes.core.k8s_info:

api_version: v1

kind: Pod

namespace: "{{ namespace }}"

label_selectors:

- "{{ label_selector }}"

register: pod_list

- name: Fail if no pods found

fail:

msg: "No pods found with label {{ label_selector }} in {{ namespace }}"

when: pod_list.resources | length == 0

- name: Select the first pod

set_fact:

target_pod: "{{ pod_list.resources[0].metadata.name }}"

- debug:

msg: "Selected pod: {{ target_pod }}"

- name: Exec command inside pod

kubernetes.core.k8s_exec:

namespace: "{{ namespace }}"

pod: "{{ target_pod }}"

container: "{{ container_name | default(omit) }}"

command: "{{ exec_command }}"

register: exec_output

- debug:

var: exec_output.stdout

Sample output