Jarvy vs Vagrant¶

A comparison of Jarvy and Vagrant for developer environment management.

Quick Comparison¶

Feature	Jarvy	Vagrant
Type	Native CLI provisioner	VM environment manager
Isolation	None (installs on host)	Full OS isolation
Overhead	Zero	VM resource overhead
Config Format	`jarvy.toml`	`Vagrantfile` (Ruby DSL)
Startup Time	Instant (after setup)	Minutes (VM boot)
Use Case	Developer tooling	Full environment simulation

When to Choose Jarvy¶

Daily development - Fast iteration without VM overhead
Simple tool provisioning - Just need Node, Docker, Terraform installed
Resource-constrained machines - No VM memory/CPU allocation needed
Quick onboarding - New devs productive in minutes
Native performance - Full host CPU/memory available
Cross-platform consistency - Same config works on macOS/Linux/Windows

When to Choose Vagrant¶

Full OS isolation - Need complete separation from host
Production environment simulation - Match prod OS exactly
Multi-machine setups - Simulate distributed systems locally
Legacy OS requirements - Run specific Linux distros
Infrastructure testing - Test provisioning scripts (Ansible, Chef)
Disposable environments - vagrant destroy and start fresh

Key Differentiators¶

Jarvy's Approach¶

Installs tools directly on your machine
No virtualization layer
Tools run at native speed
Simple TOML configuration
Permanent installation (until removed)

Vagrant's Approach¶

Creates isolated virtual machines
Provider plugins: VirtualBox, VMware, Docker, etc.
Box ecosystem for base images
Provisioning via shell, Ansible, Chef, Puppet
vagrant up, vagrant destroy lifecycle

Resource Comparison¶

Aspect	Jarvy	Vagrant
Disk space	Tools only	VM image + tools
Memory	None allocated	1-8GB per VM typical
CPU	None allocated	1-4 cores per VM typical
Startup	Instant	30-120 seconds

Configuration Comparison¶

Jarvy (jarvy.toml):

[tools]
node = "18.16.0"
docker = "latest"
terraform = "1.5.3"
python = "3.12"

Vagrant (Vagrantfile):

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/jammy64"
  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y nodejs docker.io terraform python3
  SHELL
end

Migration Considerations¶

From Vagrant to Jarvy¶

Good candidates for migration: - Simple tool installation workflows - Single-developer local setups - Projects where VM isolation is overkill

Keep Vagrant for: - Multi-machine distributed setups - Production environment simulation - Infrastructure provisioning tests

From Jarvy to Vagrant¶

Consider if you need: - Complete OS isolation - Ability to match production OS exactly - Disposable, easily rebuilt environments

Can They Work Together?¶

Yes, for specific scenarios:

Jarvy on host - Install Docker, Vagrant itself, editors
Vagrant for services - Run databases, message queues in VMs

However, most teams choose one: - Jarvy for developer tool provisioning (fast, simple) - Vagrant for full environment simulation (isolated, complete)

Summary¶

Jarvy is for installing dev tools quickly with zero overhead. Vagrant is for simulating complete environments with full isolation.

Choose Jarvy when you need tools on your machine fast. Choose Vagrant when you need to simulate a complete, isolated environment.