A Heroku buildpack for setting the ssh private key as part of the application build. It's meant to be used as part of a setup using multiple buildpacks, so other buildpacks can authenticate with hosts using ssh keys, for instance to install dependencies from private git repositories.
Add the buildpack to your Heroku app either using the CLI or the Heroku dashboard. The ssh-private-key-buildpack needs to run before any buildpack trying to get ssh access. In the following example, it runs before the heroku/go buildpack.
$ heroku buildpacks:set --index 1 https://github.com/debitoor/ssh-private-key-buildpack.git
$ heroku buildpacks:add heroku/go
Instead of setting the buildpacks directly with Heroku they can also be configured using a .buildpacks in combination with heroku-buildpack-multi.
$ heroku buildpacks:set https://github.com/heroku/heroku-buildpack-multi.git
The same example given for the CLI use would have the following .buildpacks file.
$ cat .buildpacks
https://github.com/debitoor/ssh-private-key-buildpack.git
https://github.com/heroku/heroku-buildpack-go
Set the private key environment variable SSH_KEY of your Heroku app (note that the key needs to be base64 encoded).
$ heroku config:set SSH_KEY=$(cat path/to/your/keys/id_rsa | base64)
By default the buildback adds Github to known_hosts. However you can configure your app to allow custom hosts, too. All that's needed is the set SSH_HOSTS for you app to a comma-separated list of hosts, e.g. [email protected],example.com
$ heroku config:set SSH_HOSTS="[email protected],example.com"