Vagrant: Day 01

📦 Vagrant - Day 01

1. Introduction to Vagrant

What is Vagrant? Vagrant is an open-source tool that allows you to build and manage virtualized development environments.
Benefits of Using Vagrant
- Reproducibility
- Isolation
- Simplified provisioning
Use Cases
- DevOps automation
- Testing infrastructure
- Multi-VM environments

2. Installation

Linux/Mac/Windows

Step 1: Install VirtualBox
https://www.virtualbox.org/wiki/Downloads
Step 2: Install Vagrant
https://www.vagrantup.com/downloads
Verify Installation:
```
vagrant --version
```

Getting Started with Vagrant

Vagrant boxes can be searched Here

Create a Directory and get into the dir
Create a Vagrantfile and initiate the box

vagrant init generic/rhel8 --box-version 4.3.12

It will generate a file like given below:

  Vagrant.configure("2") do |config|
  config.vm.box = "generic/rhel8"
  config.vm.box_version = "4.3.12"
end

Create a vm using this vagrantfile (Prerequisites, Virtualbox and vagrant )

vagrant up

Now check the vm from Virtual box
Also check the Network type and forwarding rule
login using putty
Warning: By Default any vm created with vagrant will have a user vagrant and password vagrant
Warning: Password Authentication is not enabled in all other os except ubuntu.
Enable SSH Password Authentication

Vagrant.configure("2") do |config|
  config.vm.box = "generic/rhel8"

  config.vm.provision "shell", inline: <<-SHELL
    # Enable password authentication
    sudo sed -i 's/^#\\?PasswordAuthentication.*/PasswordAuthentication yes/' /etc/ssh/sshd_config
    sudo sed -i 's/^#\\?UsePAM.*/UsePAM yes/' /etc/ssh/sshd_config

    # Restart SSH service
    sudo systemctl restart sshd
  SHELL
end

Run the below command

vagrant up --provision

Vagrantfile Basics

Vagrant.configure("2") do |config|
  config.vm.box = "hashicorp/bionic64"
  config.vm.network "private_network", type: "dhcp"
  config.vm.synced_folder "./data", "/vagrant_data"

  config.vm.provider "virtualbox" do |vb|
    vb.memory = "1024"
    vb.cpus = 2
  end
end

Key Options:
- config.vm.box: Defines the base box
- Networking: private, public, and port forwarding
- Synced folders: sharing between host and guest

Provisioning

Methods:
- Shell Scripts
- Ansible
- Puppet
- Chef
Inline vs External:
- Inline: Defined inside the Vagrantfile
- External: Separate script or playbook

Example (inline shell provision):

config.vm.provision "shell", inline: <<-SHELL
  apt-get update
  apt-get install -y nginx
SHELL

Basic Commands

Command	Description
`vagrant init`	Create a new Vagrantfile
`vagrant up`	Start the VM
`vagrant ssh`	SSH into the VM
`vagrant halt`	Stop the VM
`vagrant destroy`	Delete the VM
`vagrant status`	Check VM status
`vagrant box list`	List installed boxes
`vagrant box add`	Add a new box
`vagrant box remove`	Remove a box

Synced Folders

Default: /vagrant directory synced

Custom Example:

config.vm.synced_folder "./local", "/vm_data"

7. Networking

Port Forwarding

config.vm.network "forwarded_port", guest: 80, host: 8080

Private Network

config.vm.network "private_network", ip: "192.168.33.10"

Public Network
```
config.vm.network "public_network"
```

8. Multi-Machine Environments

Example:

Vagrant.configure("2") do |config|
  config.vm.define "web" do |web|
    web.vm.box = "ubuntu/bionic64"
  end

  config.vm.define "db" do |db|
    db.vm.box = "ubuntu/bionic64"
  end
end

Use cases:

Web + DB setup
HA/clustered configurations

9. Troubleshooting

Networking Issues:
- Check IP conflicts
- Restart networking service inside VM
Provisioning Errors:
- Verify scripts and paths
- Use external shell script for debugging
Debug Mode:
```
vagrant up --debug
```

10. Best Practices

Track Vagrantfile in version control
Use .gitignore to exclude .vagrant/
Use small, optimized base boxes
Clean up unused boxes:
```
vagrant box prune
```

Getting Started Quick Steps

# Step 1: Initialize
vagrant init bento/ubuntu-24.04 --box-version 202407.23.0

# Step 2: Start
vagrant up

# Step 3: SSH
vagrant ssh

# Step 4: Halt
vagrant halt

–reprovision

Usage: vagrant up --provision
Explanation: The --reprovision option is used with the vagrant up command to force the provisioning of the virtual machine, even if it has already been provisioned previously. This is useful if you want to apply changes to the provisioning scripts (such as updates or new configurations) without destroying and recreating the VM.

Resources

Example if you want to create multiple vms at the same time

 git clone https://gitlab.com/container-and-kubernetes/kubernetes-2024.git
 cd kubernetes-2024/two-vms
 vagrant up