Further to Andrew Lorente’s answer, you can also use the VAGRANT_VAGRANTFILE environment variable to specify the filename of the Vagrantfile. This has the advantage over VAGRANT_CWD of not changing the current working directory which can be useful when relying on relative paths.
For example, the following will run vagrant up on Vagrantfile.other:
VAGRANT_VAGRANTFILE=Vagrantfile.other vagrant up
Notes
- This used to appear to be an undocumented feature which was only visible in the source code.
- In later releases this is now documented in the Hashicorp docs here: Environmental Variables.