One of my development environments 🏭
Note: In the middle of adding support for Rocky Linux (work in progress but Rocky-8.4-x86_64-dvd1.iso runs).
RHEL is usually "the work Linux", but running Red Hat Enterprise Linux (RHEL) incurs a cost [1, 2]. Thankfully there are some derivativate distributions that are built from this same source code (without the non-free parts). We can use these for learning, development and testing as they are almost the same as RHEL.
The CentOS project is one of these and has been around for about 15 years. They even offically partnered [1] with Red Hat back in 2014, whose parent company as of 2019 is IBM. In 2015 Red Hat acquired Ansible (a small startup at the time) for a cool $100/150 million [1].
Ansible (written in python) cannot run on a Windows host natively, you need A macOS, Linux or *BSD operating system - so running Ansible from CentOS seems like a good idea.
Ansible is a pretty good "configuration managment" (CM) tool 🔧
I really like it for some tasks that would otherwise be manual (writing, and certainly maintaining, yaml is easier than bash for some tasks).
Use cases of CM tools are broard:
- setting up standalone machines (desktops or servers, physical or virtual)
- creating more complex systems (cloud or local dev, just learning demo or production)
- managing Firewalls, Switches, WiFi - there are Network Modules for physical and virtual networks
Doing things in Ansible can be better ⚙️
There are other tools I want to use Ansible with (like DB or Web servers), but I do not want to run these kinds of services on my host system 🏰 (whatever that might be - Mac / Lin / Win).
I need to run these daemons in isolation, and have my different projects stay private from each other, while keeping my Desktop/Laptop as clean of crummy software as possible (all code is bad code).
This is why I am using a VM. I also want to run my Ansible roles against other machines, and have a real test system.
packer will take an ISO image and create Virtual Machine image from it. This is how Vagrant "boxes" are made 📦
You can build a box and run it locally, then then build another box (with the same base config) for a cloud hosting provider (Azure, AWS EC2, Google) - if you have the need. This saves us from having to manually install our OS (RHEL).
This tool Vagrant is an abstraction layer on top of virtualisation, vagrant is a wrapper that allows us to use Virtual Machines in a more portable way 🌏
"Vagrant is a tool for building and distributing development environments."
So we can interface with Vagrant to have a similar experience, no matter our host OS or hypervisor.
What you need:
- 64 bit OS on hardware with virtualization support
- Check virtualization is enabled in your BIOS
- Hypervisor/Host Vagrant can use for a Provider
- Lots of Ram and disk help
Packer and Vagrant are cross platform (MacOS, Win, Linux, BSD), you can download pre-made binaries courtesy of Hashicorp or compile them from source.
You can adjust the amount of Virtual Machines you need, and the specs for them, by editing the Vagrantfile:
# centos8vm "admin vm" options
MY_VM_RAM = "4096"
MY_VM_CPU = "4"
MY_VM_CODE = "./code/vm/"
# Enable the multi-machine setup? yes/no
MULTIVM = "yes"
# Number of Node VMs to create?
NODES = 4
# el8node{i} options:
NODE_CPU = "2"
NODE_RAM = "2048"
NODE_CODE = "./code/node/"
See the doc/ directory.