I working with Ansible Playbook to get a count on the output of shell command, using the following task

 

I working with Ansible Playbook to get a count on the output of shell command, using the following task,

" - name: Check running number of JVM Services shell: ps -H -fu "{{ backendAppUser }}" register: apps_count become: yes become_user: "{{ backendAppUser }}" - name: Display Register var debug: var: apps_count.stdout" , however while running the task, I am getting a following error ("apps_count.stdout": "VARIABLE IS NOT DEFINED!: 'dict object' has not attribute ''stdout"

I'll address the error, provide a solution, and create a working configuration:

Understanding the Error:

• The error "VARIABLE IS NOT DEFINED!: 'dict object' has not attribute 'stdout'" indicates that the variable apps_count exists as a dictionary, but it does not contain a key named stdout. This means the shell command's output is not being captured as expected.

Resolving the Issue:

1. Ensure Correct Shell Command:

   • Verify that the ps -H -fu "{{ backendAppUser }}" command produces expected output when executed manually on the target host.
   • If necessary, adjust the command or consider using Ansible's command module, as it's generally more reliable for capturing output.

2. Modify Playbook Tasks:

   • Register Output: Use register: apps_count to capture the result of the shell command, regardless of whether it's captured under stdout or another key.

   • Check for Correct Output Structure: If the output structure is different (e.g., doesn't contain stdout), use a suitable key to access the output, such as apps_count.output or other available keys.

Working Configuration:

YAML

- name: Check running number of JVM Services
  command: ps -H -fu "{{ backendAppUser }}"
  register: apps_count
  become: yes
  become_user: "{{ backendAppUser }}"

- name: Display Register var
  debug:
    var: apps_count.output

Explanation:

• The command module is used, as it generally captures output more reliably.
• The register: apps_count captures the output in the apps_count variable.
• The debug task now displays apps_count.output to ensure the correct output is accessed.

Additional Tips:

• Use failed_when: Consider using failed_when: apps_count.rc != 0 to make the playbook fail if the command returns a non-zero exit code.
• Explore set_fact: If you need to process the output further, use set_fact to create custom variables based on the captured output.
• Test Thoroughly: Test the configuration with a small selection of hosts before deploying it widely.

By following these steps and using the provided configuration, you should be able to successfully capture and display the output of the shell command in your Ansible playbook.

Kubernetes: Orchestrating Containers like a Maestro 🪄

 

In the ever-evolving world of containerized applications, managing and scaling them effectively becomes paramount. Enter Kubernetes, an open-source container orchestration platform that has revolutionized how we deploy, manage, and scale containerized applications.

Developed by Google and released in 2014, Kubernetes (often abbreviated as "k8s") has become the de facto standard for container orchestration. It acts as a maestro, automating the deployment, scaling, and operations of containerized applications across clusters of hosts. orchestrator ‍

But why Kubernetes?

Traditional application deployments often involved manual processes and complex configurations, making scaling and managing applications cumbersome. Kubernetes simplifies this process by providing a platform to:

• Automate deployments and scaling: Define your application's desired state, and Kubernetes takes care of deploying and scaling containers to meet that state.
• Manage container lifecycles: Kubernetes handles container creation, deletion, and health checks, ensuring your application remains healthy and responsive.
• Facilitate service discovery and load balancing: Kubernetes enables applications to discover and communicate with each other easily, while also providing built-in load balancing for distributing traffic across container instances. ⚖️
• Self-healing capabilities: If a container fails, Kubernetes automatically restarts it, ensuring your application remains highly available.

How does Kubernetes work? ⚙️

At the heart of Kubernetes lies a cluster architecture composed of various components:

• Master node: The brain of the operation, responsible for scheduling container workloads across worker nodes and managing the overall state of the cluster.
• Worker nodes: The workhorses of the cluster, running containerized applications as instructed by the master node. ️
• Pods: The smallest deployable unit in Kubernetes, consisting of one or more containers that share storage and network resources.
• Deployments: Manage the desired state of your application by deploying and scaling pods.
• Services: Abstractions that expose pods to other applications or users within the cluster. ✨

Here's a simplified example:

1. You define your application as a set of containerized services using YAML files.
2. You deploy the application using kubectl, the Kubernetes command-line tool.
3. The master node schedules the pods containing your containers across available worker nodes in the cluster.
4. Kubernetes manages the lifecycles of your pods, ensuring they run healthy and scaled as needed.

Exploring Further:

For a deeper dive into Kubernetes, check out the following resources:

• Kubernetes official documentation: https://kubernetes.io/docs/home/
• Interactive Kubernetes tutorials: https://labs.play-with-k8s.com/
• Getting started with kubectl: https://kubernetes.io/docs/tutorials/

By embracing Kubernetes, you can streamline your containerized application deployments, gain better control over your infrastructure, and empower your development teams to focus on building innovative applications, not managing infrastructure complexities.

Remember, this is just a glimpse into the vast world of Kubernetes. As you explore further, you'll discover its extensive capabilities and how it can empower you to build and manage modern, scalable applications like a maestro! 🪄