Configuration versions are the mechanism by which Vagrant 1.1+ is able to remain backwards compatible with Vagrant 1.0.x Vagrantfiles, while introducing dramatically new features and configuration options.
If you run
vagrant init today, the Vagrantfile will be in roughly the
Vagrant.configure("2") do |config| # ...end
"2" in the first line above represents the version of the configuration
config that will be used for configuration for that block (the
section between the
do and the
end). This object can be very
different from version to version.
Currently, there are only two supported versions: "1" and "2". Version 1 represents the configuration from Vagrant 1.0.x. "2" represents the configuration for 1.1+ leading up to 2.0.x.
When loading Vagrantfiles, Vagrant uses the proper configuration object for each version, and properly merges them, just like any other configuration.
The important thing to understand as a general user of Vagrant is that
within a single configuration section, only a single version can be used.
You cannot use the new
config.vm.provider configurations in a version 1
configuration section. Likewise,
config.vm.forward_port will not work
in a version 2 configuration section (it was renamed).
If you want, you can mix and match multiple configuration versions in the same Vagrantfile. This is useful if you found some useful configuration snippet or something that you want to use. Example:
Vagrant.configure("1") do |config| # v1 configs...end Vagrant.configure("2") do |config| # v2 configs...end
Vagrant::Config.run? You may see this in Vagrantfiles. This was actually how Vagrant 1.0.x
did configuration. In Vagrant 1.1+, this is synonymous with