Why wont vagrant use my ssh config when using the box_url option with scp

Im trying to distribute a packaged base box and I want to use one of my existing servers that global developers have access to with a pem file.

I am aware of vagrant cloud but that is not an option in this case.

It looks like the packaged curl command does indeed support scp but for some reason it is not respecting the values I have in my ~/.ssh/config and it's not providing the identity file and username when vagrant up is ran.

I can confirm that the following command does work.

/opt/vagrant/embedded/bin/curl --verbose \
  "scp://myurl.com:/path/to/base.box" --insecure \
  --key ~/.ssh/my-key.pem --user admin: --output test.box

How can i pass the required options to the base_url or make the packaged version of curl respect my ssh config file?

Here is the config block im using in my vagrantfile

  config.vm.define :devbox, primary: true do |devbox|
    devbox.vm.box_download_insecure = true
    devbox.vm.box = "base-box"
    devbox.vm.box_url = "scp://mydomain.com:/path/to/base.box"
  end

Any guidance would be greatly appreciated, I have wasted about 10 hours on this so far.

Solution

After submitting an issue on the vagrant github project: https://github.com/hashicorp/vagrant/issues/11546

They have responded and released an update in version 2.2.9 that will allow you to specify additional box download options.

The necesary keys that are needed are in the below example, but you can pass any curl argument as the key and its value as the value.

config.vm.box_url = "scp://example.com:/path/to/your/box.box"
config.vm.box_download_options = {
  key: "~/.ssh/secretkey.pem",
  user: "username:" # Important, keep the : for no password
}

it is important to add the : after the username as that denotes there is no password since we are using private key authentication.

Hope this helps someone else.