Local Vagrant Configuration

Vagrantfile

# ~/.vagrant.d/Vagrantfile

# Local configuration to use across all Vagrant machines

Vagrant.configure("2") do |config|
  config.vm.provider :virtualbox do |vb|
    host = RbConfig::CONFIG['host_os']
    
    # Force settings for allowed resources
    if host =~ /darwin/
      # Dynamically look up resources for Macs
      cpus = `sysctl -n hw.ncpu`.to_i
      # sysctl returns Bytes and we need to convert to MB
      mem = `sysctl -n hw.memsize`.to_i / 1024 / 1024
    elsif host =~ /linux/
      # Improve linux performance by only counting physical cores and not hyperthreads
      cpus = `grep "cpu cores" /proc/cpuinfo |sort -u |cut -d":" -f2`.to_i
      # meminfo shows KB and we need to convert to MB
      mem = `grep 'MemTotal' /proc/meminfo | sed -e 's/MemTotal://' -e 's/ kB//'`.to_i / 1024
    else # sorry Windows folks, I can't help you
      # Fall back to statically set values
      # **Note**: Update these for your system if using this
      cpus = "4"
      mem = "4096"
    end
    
    # Adjust values here if you don't want to allow access to all resources
    # Eg. mem = mem / 4 # This would limit access to only a quarter of total memory
    
    # Increase allowed memory usage and cpus
    vb.customize ["modifyvm", :id, "--cpuexecutioncap", "90", "--memory", mem, "--cpus", cpus]
  end

  # vagrant-cachier plugin configuration
  if Vagrant.has_plugin?("vagrant-cachier")
    # Cache downloaded packages per box
    config.cache.scope = :box
  end

  # vagrant-exec plugin configuration
  if Vagrant.has_plugin?("vagrant-exec")
    # By default run vagrant-exec commands within the /vagrant directory
    config.exec.commands '*', directory: '/vagrant'
    # Run all drush commands within the Drupal root
    config.exec.commands 'drush', directory: '/vagrant/docroot'
  end
end

Updated this to dynamically calculate available resources where possible.

Updated to fix the following error:

There was an error loading a Vagrantfile. The file being loaded
and the error message are shown below. This is usually caused by
a syntax error.

Path: <provider config: virtualbox>
Line number: 8
Message: NameError: undefined local variable or method `host' for main:Object