I have a Vagrant box where I want to SSH in as the standard vagrant user for the initial provision and deployment, but I want to use my own alternate custom user account for my dev work.

I want to use vagrant for the initial deploy as that is the standard user for many vagrant machine images. Adding my own user into the image would be a pain, and would prevent me from being able to use a standard Vagrant image.

I want to add my custom deploy user during provisioning, and use that for my dev work, because that is the account my staging and production servers use. Having this user account present for dev work will allow me to be more consistent with our real environments.

Unfortunately, that was a bit more challenging to do than I would have anticipated, and I could not find an option in the Vagrant docs that would allow me to use two different users for vagrant up and vagrant ssh.

Eventually, I found this solution by GitHub user danielfrg.

Edit your Vagrantfile and add this conditional in the configure block. 

VAGRANT_COMMAND = ARGV[0]

Vagrant.configure("2") do |config|
	if VAGRANT_COMMAND == "ssh"
		config.ssh.username = 'other_username'
	end

	...
end

Perfect. Now my other_username (deploy in my case) will only be used if the ssh argument is passed to vagrant.