ssh-private-key-buildpack

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.

Example usage

Configure Multiple Buildpacks

Option 1: Heroku CLI or Dashboard

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

Option 2: Use heroku-buildpack-multi

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

Configure SSH Key

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. git@github.com,example.com

$ heroku config:set SSH_HOSTS="git@github.com,example.com"

Additonal Hosts For Private Key (For use with non-Github private repositories)

To associate additional hosts with the private key -- for example, bitbucket -- set the environment variable SSH_HOSTS to a comma-separated list of [username]:host.

For example, to associate the key with only Bitbucket, the SSH_HOSTS variable would be: SSH_HOSTS=git@bitbucket.org. To associate multiple hosts (e.g. Github and Bitbucket), set SSH_HOSTS=git@github.org,git@bitbucket.org

This can be done in the Heroku console, or via the Toolbelt CLI with:

$ heroku config:set SSH_HOSTS="git@github.com,example.com,git@bitbucket.org"