Concerning Vagrant with Digital Ocean as a Provider and multiple users...

When specifying the DigitalOcean user account that will create the droplet, you can only set one user and API token. Though you can still take advantage of all the different powerful provisioners that Vagrant can employ to configure the droplet. You can create new user accounts, add ssh keys, etc…

Here’s an extremely simple example that runs the command ssh-import-id on the newly created droplet to import the public ssh keys associated with the GitHub user andrewsomething It’s one quick way to get another developer’s key on the machine:

Vagrant.configure('2') do |config|

  config.vm.provider :digital_ocean do |provider, override|
    override.ssh.private_key_path = '~/.ssh/id_rsa'
    override.vm.box = 'digital_ocean'
    override.vm.box_url = "https://github.com/smdahlen/vagrant-digitalocean/raw/master/box/digital_ocean.box"

    provider.token = 'MY_API_TOKEN'
    provider.image = '14.04 x64'
    provider.region = 'nyc3'
    provider.size = '512mb'
    provider.ssh_key_name = 'ssh_key_name'
  end

  config.vm.provision "shell",
    inline: "ssh-import-id gh:andrewsomething"

end

This uses the “shell” provisioner, but you can also use more sophisticated configuration management tools like Puppet, Chef, and Ansible.