Vagrant

Vagrant is an automation tool to manage VM lifecycle, right from creating a
virtual machine to making any changes, deleting it, recreating it, provisioning
it, anything that we do manually with VMs, we can automate that by using
vagrant. Vagrant is a command line tool.

VM Management process

• OS Installations
• Time Consuming
• Manual setup
• Tough Replication for Multi VM
• Documentations for Multi VM

Vagrant for VM’s

• No OS installations
• VM Setup through Images(vagrant boxes)
• Images/ Boxes available in Vagrant cloud
• Manage VM’s with a file(Vagrantfile)
• VM changes automatic through Vagrantfile
• Vagrant commands to manage VM’s
• Provisioning VM/ Executing commands & scripts

Vagrant Architecture

Vagrant file: Vagrant file is file that is written in ruby language and has all the informatio related machine like VM info network info [public, private], Disk, RAM, Software, Sync directory.

To setup vagrant VM

• First install virtual box like virtual box or VM workstation.
• Now install vagrant and install in your host machine not in VM.
  • check by using vagrant –version command.
• Create a Project Directory(Folder/Directory at any location of your choice)
• Run vagrant init to initalize a vagrant file.
  • This will create a vagrant file in that directory.
  • Now modify the file based on your requirement.
  • Below is an example to setup a UBUNTU24.04 machine
  • Yo can use any box by going to hashicorp site.

Vagrant.configure("2") do |config|
 
  config.vm.box = "bento/ubuntu-24.04"
  config.vm.box_version = "202502.21.0"
 
  config.vm.hostname = "Dipendra"
 
  config.vm.network "private_network", ip: "192.168.56.210"
 
#config.vm.network "public_network", bridge: "Killer(TM) Wi-Fi 7 BE1750x 320MHz Wireless Network Adapter (BE200NGW)"
 
  # config.vm.synced_folder "../Ubuntu24.04", "/home/ubuntu"
 
  config.vm.provider "virtualbox" do |vb|
  vb.name = "Ubuntu24"
  vb.memory = 4024
  vb.cpus = 4
  end
  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
  #   apt-get install -y apache2
  SHELL
end

• Now run the machine using Vagrant commands like vagrant up
• Login with ‘vagrant ssh’ command for Linux VM.
  • By default hostname is vagrant and password is also vagrant.

Commands

• Vagrant up → to start vm
• Vagrant ssh → to login vm
• Vagrant halt → to poweroff vm
• Vagrant reload → to reload/reboot vm
• Vagrant destroy → to delete vm
• vagrant global-status → to see the status of all the VMs. It also shows some stale information.
• vagrant global-status –prune → to remove old information
• vagrant status → to show vm status in the current directory

Other Configurations

• Vagrant IP, Memory & CPU
  • Vagrant IP and network
    • Bridged network
    • private_network
  • Changing RAM size
    • vb.memory = “value” #Allocating RAM
    • vb.cpus = “value” #Allocation core
  • Vagrant Sync Directories
    • Default sync directory inside vm
      • /vagrant/
    • Use Cases
      • preserve the files in the vm where there is a chance of vm being corrupted
        or aborted
      • When using the IDEs for coding
    • Syntax:
      • config.vm.synced_folder “../data”, “/opt/vagrant_data”
      • config.vm.synced_folder “./shared_folder”, “/home/vagrant/shared_folder”
    • Here:
      • ./Shared_folder is the folder of our host machine
      • /home/vagrant/shared_folder is the path to the virtual machine
  • Provision
    • Means executing the commands or scripts when the vm comes up. In other technologies, this is also called bootstrapping.
    • config.vm.provision “shell”, inline: <<-SHELL
      Write script here
      SHELL
    • On a already created vm, update the Vagrantfile and run
    • vagrant reload –provision

📝 Vagrant VM Management: Full Setup Guide (Using 127.0.0.1)

This guide provides the robust steps to connect and manage your new VM (db-server) from any directory on your Linux host.

Step 1: Initial VM Setup & Preparation 🚀

1. Configure VM:
   • Ensure your new VM’s Vagrantfile has a unique hostname and static IP:Rubyconfig.vm.network "private_network", ip: "192.168.56.220" # Static IP (For network access) config.vm.hostname = "db-server"
2. Start the VM: cd /path/to/new/vm/folder vagrant up

Step 2: System Integration (SSH Config) 🔗

This step allows you to connect (ssh) to the VM from anywhere using a simple name.

1. Generate and View the Key Path: While inside the new VM’s directory, generate a temporary config file, and use cat to view the required key path:
   • Generate the config and save it to a temporary file vagrant ssh-config > temp_config.txt
   • View the key path cat temp_config.txt | grep IdentityFile
     • Copy the absolute path that is output (it will look like /home/dipendra/.../private_key).
     • You can then delete temp_config.txt.
2. Edit the Global SSH Config: Open your primary SSH configuration file:
   • nano **~/.ssh/config**
3. Paste & Customize the Block: Paste the configuration block at the bottom. This uses the reliable 127.0.0.1 (localhost) connection method:

Host db-server # <--- RENAME THIS: Use the VM's hostname or a unique  name HostName
127.0.0.1 # <--- Use reliable localhost IP
User vagrant
Port 2222 # <--- Use the standard Vagrant port
UserKnownHostsFile /dev/null
StrictHostKeyChecking no
PasswordAuthentication no
Identity file /path/to/new/vm/folder/.vagrant/machines/default/virtualbox/private_key # <--- PASTE KEY PATH HERE
IdentitiesOnly yes
LogLevel FATAL

Or simply copy paste this command output in .ssh/config file

1. Save and Exit.
2. Test the Connection: Test the direct connection from anywhere on your host system:ssh db-server

Step 3: Workflow Automation (CLI Aliases) ⚙️

This step allows you to manage (vagrant up, halt) the VM from anywhere using custom commands.

1. Open your shell configuration file:
   • nano ~/.bashrc (Use ~/.zshrc if you use Zsh)
2. Add the Startup and Shutdown Aliases:
   • Paste the following aliases, replacing the host name (db-server) and the directory path with the details for your new VM:
     • # Vagrant Shortcuts for DB Server VM
       • alias db-up='(cd /path/to/new/vm/folder && vagrant up)'
       • alias db-down='(cd /path/to/new/vm/folder && vagrant halt)'
3. Save, Exit, and Reload: Apply the changes to your current shell session:
   • **source ~/.bashrc**

💡 Alternative: Static IP Connection Note

If you find that the 127.0.0.1:2222 connection is slow or unstable, you can try connecting directly to the static IP you configured, as it sometimes offers better performance:

To switch to the static IP method, simply change the HostName in your ~/.ssh/config file to the static IP and remove the Port 2222 line:

Host deployment
  HostName 192.168.56.212
  User vagrant
  Port 22 //optional
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentityFile /path
  IdentitiesOnly yes
  LogLevel FATAL
  PubkeyAcceptedKeyTypes +ssh-rsa
  HostKeyAlgorithms +ssh-rsa