FAQ: Vagrant: Setting Up and Managing Your Vagrant VM

Setting Up and Managing Your Vagrant VM

Link to Vagrant

Overview

This guide provides a comprehensive solution for managing a remote Vagrant image with a configuration file held in a Git repository. It includes steps for downloading and provisioning the VM, resetting it to its original state, and automatically detecting changes in provisioning.

Solution

1. Remote Vagrant Image and Configuration:

   • The Vagrant configuration file (Vagrantfile) and necessary provisioning scripts are stored in a Git repository.
   • When developers clone the repository, they get the Vagrantfile and provisioning scripts.
   • The Vagrantfile includes instructions to download and provision the VM using apt-get and other necessary configurations.

2. Resetting the VM:

   • Developers can reset the VM back to its original state by destroying and recreating it using a provided script.

3. Automatic Provisioning Detection:

   • When developers pull the latest changes from the Git repository, the setup detects any changes in the provisioning scripts and prompts for a VM rebuild if needed.

Git Repository Structure

<repository-root>
├── Vagrantfile
├── provision.sh
├── check_provisioning.sh
├── vm_reset.sh
└── vm_start.sh

Scripts and Configuration

Vagrantfile

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

  # Run the provisioning check script before starting the VM
  config.trigger.before :up do
    run "bash check_provisioning.sh"
  end

  config.vm.provision "shell", path: "provision.sh"
  
  config.vm.synced_folder ".", "/vagrant"
end

provision.sh

#!/bin/bash

# Update package lists
sudo apt-get update

# Install necessary packages
sudo apt-get install -y git curl vim

check_provisioning.sh

#!/bin/bash

# Path to the stored hash file
HASH_FILE=".provision_hash"

# Generate a new hash for the provisioning script
NEW_HASH=$(sha256sum provision.sh | awk '{ print $1 }')

# Check if the hash file exists
if [ -f "$HASH_FILE" ]; then
  OLD_HASH=$(cat "$HASH_FILE")
  if [ "$NEW_HASH" != "$OLD_HASH" ]; then
    echo "Provisioning script has changed. Please run './vm_reset.sh' to rebuild the VM."
  fi
fi

# Store the new hash
echo "$NEW_HASH" > "$HASH_FILE"

vm_reset.sh

#!/bin/bash

# Destroy the current VM
vagrant destroy -f

# Recreate and provision the VM
vagrant up

vm_start.sh

#!/bin/bash

# Start the VM
vagrant up

Instructions for Manual

---

Setting Up and Managing Your Vagrant VM

1. Clone the Repository

First, clone the repository containing the Vagrant configuration and scripts:

git clone <repository-url>
cd <repository-directory>

2. Start the VM

To start the VM, simply run the provided vm_start.sh script:

./vm_start.sh

This script will:

• Check for changes in the provisioning script using check_provisioning.sh.
• Start the VM and apply the provisioning defined in provision.sh.

3. Reset the VM

If you need to reset the VM to its original state, run the vm_reset.sh script:

./vm_reset.sh

This script will:

• Destroy the current VM.
• Recreate and re-provision the VM from scratch.

4. Pull the Latest Changes

To update your local repository with the latest changes from the remote repository, run:

git pull

5. Check for Provisioning Changes

Before the VM starts, the check_provisioning.sh script will automatically run to detect any changes in the provisioning script. If changes are detected, you will see a message prompting you to reset the VM using ./reset.sh.

Scripts Overview

• Vagrantfile: Defines the VM configuration and provisioning.
• provision.sh: Contains commands to install required packages and configurations.
• check_provisioning.sh: Checks if the provisioning script has changed and prompts for a VM reset if needed.
• vm_reset.sh: Destroys and recreates the VM.
• vm_start.sh: Starts the VM.