The Tech Chorus blog, started by Sudheer Satyanarayana in 2008, has evolved through various hosting technologies and software over the years. This post captures that journey, highlighting the transitions, challenges, and decisions that shaped its infrastructure.

The Early Days: Drupal and LAMP

Back in the day, the blog ran on the Drupal content management system (CMS), a popular choice among developers. The LAMP (Linux, Apache, MySQL, PHP) stack dominated web hosting at the time, and Drupal was one of my favorite CMSes. The site was hosted on a cPanel server, making management relatively straightforward.

Using Git with SSH is a common practice among software developers. The convenience of not having to remember passwords is a huge productivity boost in software development workflows.

In a previous blog post, I wrote about managing SSH keys.

Having many SSH keys can cause few issues:

• ssh-agent doesn’t work well with too many keys.
• Can’t always map SSH keys to servers in SSH client configuration. Both personal and company projects Git can be hosted on the same server or third-party service such as Github.
• Some Git hosting services do not allow you to use the same SSH key in more than one user profile. You are forced to have a unique SSH keypair per user profile.
• The SSH server might refuse to allow too many authentication attempts.

Git allows you to set the environment variable GIT_SSH_COMMAND. If you set this environment variable, Git uses the specified command for push and pull operations.

What is SSH Key Management?

The blog post is intended towards someone new to SSH key management. Do you have just one SSH key pair? Do you have multiple key pairs? What are some pros and cons of having single or multiple key pairs? The post answers such questions about SSH key usage in practice.

The Premise

So, someone walked up to you or in a video call asked for your SSH public key?

In this blog post, I will explain how I implemented a graph algorithm to solve the database migration problem in an application pluggable module system.

Prerequisites:

• Working knowledge of Python
• Working knowledge of Graph Theory. Familiar with the terms: Edge, vertex, path, sink, source, digraph, path graph, etc.

Gavika Web Framework has a pluggable module system. The modules can be developed independently. They can be installed, upgraded and removed from the main application. Gavika Web Framework is written using Python, Flask, SQLAlchemy and a bunch of other related technologies and libraries.

AWS Certified Solutions Architect - Associate is one of the most sought-after certifications in the IT industry.

Here’s a few tips for those seeking this certification.

Background Knowledge And Experience

AWS recommends “at least one year of hands-on experience designing available, cost-efficient, fault-tolerant, and scalable and distributed systems on AWS.” In other words, if you recently started your career in IT, there are a few things you have to do before you start preparing for this certification.

Introduction

The article explains how to run your own OpenVPN server. We will create a Certificate Authority Server and an OpenVPN server. We will also generate certificates for the clients. We will also learn how to manage revocation of client certificates using the Ansible roles.

Use the Ansible roles gavika.openvpn and gavika.easy_rsa to install and configure your OpenVPN server.

You can install the OpenVPN server on any public cloud or hosting provider or on-premise servers. The Ansible roles are designed to install the OpenVPN server and a Certificate Authority server.

We are pleased to announce gavika.administrators.

The Ansible role provides a declarative method to create Linux user accounts with administrative privileges. In other words, these users have sudo access without password and are empowered to run all commands on the system.

You might be wondering why you would need a role when you can write a couple tasks yourselves in an Ansible playbook. The reason is, Do Not Repeat Yourself(DRY). Instead of writing such tasks over and over, use the abstraction provided by the role. You just have to write some YAML declaration and be done with it. Moreover, the maintenance is outsourced to an Apache licensed open source software. The role has Molecule tests to boost your confidence.

Yesterday, we announced the launch of Ansible role to install and configure AWS CloudWatch Agent.

You might have seen my other open source Ansible roles on Ansible Galaxy and Github.

In the same spirit, the company, Gavika Information Technologies Pvt. Ltd. Bangalore, has started publishing open source projects on Github.
Ansible role to install and configure AWS CloudWatch Agent is the first project. Expect more projects in the future.

These are some guidelines for the Ansible role projects that Gavika follows:

Install the Ansible role gavika.aws_cloudwatchagent via Galaxy

ansible-galaxy install gavika.aws_cloudwatchagent

Create The Playbook File - cw-play.yml :

---
- hosts: all
  become: true
  vars:
  roles:
    - role: gavika.aws_cloudwatchagent

Prepare the AWS CloudWatch Agent configuration

In your variables file, use aws_cloudwatch_agent_config

agent:
    metrics_collection_interval: 60
    run_as_user: "cwagent"
    metrics:
      namespace: "Gavika"
      append_dimensions:
        InstanceId: "${aws:InstanceId}"
      metrics_collected:
        disk:
          measurement:
            - used_percent
          metrics_collection_interval: 60
          resources:
            - "*"
        mem:
          measurement:
            - mem_used_percent
          metrics_collection_interval: 60

In this example, I am using the namespace, Gavika. Feel free to change it. We collect the cpu, disk, diskio, mem and swap metrics. The agent will send these metrics once in 360 seconds.

Ansible comes with a vault feature. It is meant to be used in the context of configuration management. But you can also use it as a standalone simple password vault for your personal or organization’s use.

Initial setup of password vault:

• Create or clone a Git or another SCM repository

git init 

• Create the password vault

ansible-vault create myvault.secret

Type the new master password and confirm, ansible-vault will open your text editor. Type your secrets in the editor and save and quit. To open your vault for viewing or editing in the future, you will need your vault password.