RedHat Open-shift and Kubernetes Automation - Ansible Approach

 Hi Folks,

So, I here is a brief POC that I was doing to automate the open-shift based test cases using Ansible.

We are using kubernetes client in Ansible.

Steps for installation

>yum install python3 -y

>yum install curl -y

>curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py

>python get-pip.py

(you can install ansible using the pip3 or subscription-manager on rhel)

>pip3 install ansible -y

(On control node in my case it was the rhel infra node, from which i was

accessing rest of the ocp cluster nodes)

Also, to resolve, following errors: ([WARNING]: Unable to parse /etc/ansible/hosts as an inventory source [WARNING]: No inventory was parsed, only implicit localhost is available [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all' [WARNING]: Could not match supplied host pattern, ignoring: a)

Perform following:

>ssh-keygen

> ssh-copy-id key to self node(your control node or localhost or infra node , from where you are accessing rest of your cluster nodes.)

> ssh root@<controlnode> (one time setup, for accessing and accepting the 'yes' prompt.)

Note: Rest of the ansible warning can be removed by providing appropriate setting in ansible.cfg file which can be created in the working directory manually if it is not created at the time of ansible installation.

Create hosts file in the working directory as below:

[server]

localhost

<hostname of control node>

Example 1:

Now, create playbook1.yaml file and paste following content:

---

- name: Network Getting Started First Playbook

  hosts: all

  connection: local

  become: true

  become_user: root

  tasks:

    - name: Connect to worker pod and fetching cluster definition and pod states.

      kubernetes.core.k8s_exec:

        namespace: ibm-spectrum-scale

        container: gpfs

        pod: worker0

        command: "{{ item }}"

      with_items:

      - mmlscluster

      - mmgetstate -a

      register: command_output

    

- name: Cluster definition and Pod states output.

      debug:

        msg: "{{command_output}}"

    - name: Validating pod states.

      assert:

        that:

          -  "'worker0' and 'active' in command_output.results[1].stdout"

          -  "'worker1    active' in command_output.results[1].stdout"

          -  "'worker2    active' in command_output.results[1].stdout"

          -  "'worker3    active' in command_output.results[1].stdout"

        fail_msg: "Testcase Failed."

        success_msg: "Testcase Passed."

  register: Assert_out

    - name: Output Assertion 

      debug:

    msg: "{{Assert_out}}"

...

Run the command using ansible-playbook.

Ansible-playbook playbook1.yaml

--------------------------------------------------------

Kudos! You have setup and ran first ansible playbook with assertions. Similarly you can explore more.

try another example:

Example 2

---

- name: Second Playbook

  hosts: all

  connection: local

  become: true

  become_user: root

  tasks:  

    - name: File creation on worker pod.

      kubernetes.core.k8s_exec:

        namespace: ibm-spectrum-scale

        container: gpfs

        pod: worker0

        command: "{{ item }}"

      with_items:

      - cd /

      - pwd

      - mkdir test_demo

      - touch /test_demo/test_demo4.txt

      - ls

      register: command_output

  

    - name: Command output

      debug:

        msg: "{{command_output}}"

    

# copy content into a file in the remote pod

    - name: Copy content to file inside the pod

      kubernetes.core.k8s_cp:

        state: to_pod

        namespace: ibm-spectrum-scale

        container: gpfs

pod: worker0

        remote_path: /test_demo/test_demo4.txt

        content: "This content will be copied into remote file"

- name: Cleanup for files.

      kubernetes.core.k8s_exec:

        namespace: ibm-spectrum-scale

        container: gpfs

        pod: worker0

        command: "{{ item }}"

      with_items:

      - cd /

      - pwd

      - cd /test_demo

      - rm -rf /test_demo/test_demo4.txt

      - pwd

      - ls

      register: cleanup_step

    - name: Cleanup output.

      debug:

         msg: "{{cleanup_step}}"

...

 

kudos again!!!! you have automated the tasks for accessing and writing inside pod.

Video link

https://youtu.be/C7dU_v_EXTw

will keep posting more content.

References:

https://github.com/ansible-collections/kubernetes.core/blob/main/docs/kubernetes.core.k8s_exec_module.rst

https://github.com/ansible-collections/kubernetes.core/blob/main/docs/kubernetes.core.k8s_module.rst

https://github.com/ansible-collections/kubernetes.core/blob/main/docs/kubernetes.core.k8s_cp_module.rst