Vagrant Development

Use Pyreload in Vagrant virtual machines for consistent development environments.

Why Pyreload with Vagrant?

Vagrant provides:

• Consistent development environments
• Isolated system dependencies
• Team-wide reproducibility

Pyreload enhances Vagrant workflows by:

• Auto-restarting applications on file changes
• Watching files across host/guest boundaries
• Enabling rapid development iteration

Setup

Install Pyreload in Guest

Add to your Vagrantfile provisioning:

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"

  config.vm.network "forwarded_port", guest: 8000, host: 8000

  config.vm.synced_folder ".", "/vagrant"

  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y python3 python3-pip
    pip3 install pyreload
  SHELL
end

Alternative: Install in Project

config.vm.provision "shell", inline: <<-SHELL
  cd /vagrant
  pip3 install -e .
  pip3 install pyreload
SHELL

File Watching with Synced Folders

Use Polling Mode

Native file watching doesn't work well across synced folders. Use polling:

# .pyreload.yml
polling: true
poll_interval: 1.0

watch:
  - /vagrant/src
  - /vagrant/config

ignore:
  - "**/__pycache__/**"
  - ".vagrant/**"

Start Pyreload

vagrant ssh
cd /vagrant
pyreload --polling app.py

Example: Flask Application

Project Structure

myproject/
├── Vagrantfile
├── .pyreload.yml
├── app.py
├── requirements.txt
└── templates/
    └── index.html

Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"

  # Forward Flask port
  config.vm.network "forwarded_port", guest: 5000, host: 5000

  # Mount project directory
  config.vm.synced_folder ".", "/vagrant",
    type: "virtualbox",
    owner: "vagrant",
    group: "vagrant"

  # Provision
  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y python3 python3-pip
    pip3 install -r /vagrant/requirements.txt
    pip3 install pyreload
  SHELL

  # Auto-start application
  config.vm.provision "shell", run: "always", inline: <<-SHELL
    cd /vagrant
    nohup pyreload --polling app.py > /vagrant/pyreload.log 2>&1 &
  SHELL
end

.pyreload.yml

polling: true
poll_interval: 1.0

watch:
  - /vagrant

extensions:
  - py
  - html
  - css

ignore:
  - ".vagrant/**"
  - "**/__pycache__/**"
  - "**/*.pyc"

clean: true

Start Development

# Start VM
vagrant up

# SSH into VM
vagrant ssh

# Start Pyreload (if not auto-started)
cd /vagrant
pyreload app.py

# Edit files on host, see changes in VM

Example: Django Project

Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"

  config.vm.network "forwarded_port", guest: 8000, host: 8000
  config.vm.synced_folder ".", "/vagrant"

  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y python3-pip postgresql
    pip3 install Django pyreload psycopg2-binary
  SHELL
end

.pyreload.yml

polling: true
poll_interval: 1.5

watch:
  - /vagrant/mysite
  - /vagrant/templates
  - /vagrant/static

extensions:
  - py
  - html
  - css
  - js

ignore:
  - ".vagrant/**"
  - "staticfiles/**"
  - "**/__pycache__/**"

Run Django

vagrant ssh
cd /vagrant
pyreload manage.py runserver 0.0.0.0:8000

Performance Optimization

Reduce Synced Folder Overhead

Use NFS for better performance:

config.vm.synced_folder ".", "/vagrant",
  type: "nfs",
  nfs_udp: false

Adjust Poll Interval

Balance responsiveness vs. CPU usage:

# Fast (more CPU)
poll_interval: 0.5

# Normal
poll_interval: 1.0

# Slow (less CPU)
poll_interval: 2.0

Exclude Large Directories

ignore:
  - ".vagrant/**"
  - "node_modules/**"
  - ".venv/**"
  - "**/__pycache__/**"

Multi-VM Setup

Vagrantfile

Vagrant.configure("2") do |config|
  # API Server
  config.vm.define "api" do |api|
    api.vm.box = "ubuntu/focal64"
    api.vm.network "forwarded_port", guest: 5000, host: 5000
    api.vm.network "private_network", ip: "192.168.50.4"

    api.vm.synced_folder "./api", "/vagrant"

    api.vm.provision "shell", inline: <<-SHELL
      pip3 install pyreload flask
    SHELL
  end

  # Worker
  config.vm.define "worker" do |worker|
    worker.vm.box = "ubuntu/focal64"
    worker.vm.network "private_network", ip: "192.168.50.5"

    worker.vm.synced_folder "./worker", "/vagrant"

    worker.vm.provision "shell", inline: <<-SHELL
      pip3 install pyreload celery
    SHELL
  end
end

Start Services

# Terminal 1: API server
vagrant ssh api
cd /vagrant
pyreload --polling app.py

# Terminal 2: Worker
vagrant ssh worker
cd /vagrant
pyreload --polling worker.py

Troubleshooting

File Changes Not Detected

Use polling mode:

pyreload --polling app.py

High CPU Usage

Increase poll interval:

polling: true
poll_interval: 2.0

Permission Errors

Fix synced folder permissions:

config.vm.synced_folder ".", "/vagrant",
  owner: "vagrant",
  group: "vagrant"

Slow Syncing

Use NFS or rsync:

config.vm.synced_folder ".", "/vagrant",
  type: "rsync",
  rsync__exclude: [".git/", "__pycache__/"]

Best Practices

1. Always use polling: Native watching doesn't work with synced folders
2. Optimize poll interval: Balance speed and CPU usage
3. Exclude unnecessary files: Ignore build artifacts and dependencies
4. Use NFS: Faster than VirtualBox shared folders
5. Forward ports: Make services accessible from host

Complete Example

Directory Structure

myproject/
├── Vagrantfile
├── .pyreload.yml
├── requirements.txt
├── src/
│   ├── app.py
│   └── config.py
└── tests/
    └── test_app.py

Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"
  config.vm.network "forwarded_port", guest: 8000, host: 8000

  config.vm.synced_folder ".", "/vagrant", type: "nfs"

  config.vm.provider "virtualbox" do |vb|
    vb.memory = "2048"
    vb.cpus = 2
  end

  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y python3-pip
    pip3 install -r /vagrant/requirements.txt
    pip3 install pyreload
  SHELL
end

.pyreload.yml

polling: true
poll_interval: 1.0

watch:
  - /vagrant/src
  - /vagrant/config

extensions:
  - py
  - yaml

ignore:
  - ".vagrant/**"
  - "tests/**"
  - "**/__pycache__/**"

clean: true
verbose: false

Workflow

# Start VM
vagrant up

# SSH and start development
vagrant ssh
cd /vagrant
pyreload src/app.py

# Edit files on host machine
# See changes automatically reflected in VM

See Also

• Docker Development
• Polling Mode