Add var to allow a pre-generated SSH key to be passed to the ACM module

[thecodejunkie]

The current implementation of the ACM module only allows you to generate a new SSH key or not to create the git-secret at all. Ideally it should be possible to pass in an ssh_key variable as well, so you have the ability to pass in a pre-generated key.

Something like this would be nice functionality

• Was ssh_key provided?
  • Yes - > Use it
  • No -> Is create_ssh_key set to true?
    • Yes -> Generate one
    • No -> Do nothing

[morgante]

Would you want this to be the actual private key (contents) or a file path? I'm thinking contents would be more flexible (since you can always grab them from a file using file() in your config.

[thecodejunkie]

Oh sorry, forgot to mention that. Yes, I think the ideal would be to pass in the content of the file since it provides more flexibility in where the config originates from

[thecodejunkie]

@morgante what're your thoughts about completely replacing the create_ssh_key variable (and corresponding usage of tls_private_key) with a ssh_key variable? I feel that by introducing the ability to pass in a key, it should not be the responsibility for the ACM module to generate one for you. Either you grab your key from whatever location you wish or you make use of tls_private_key yourself and pass the output as the value to the ssh_key parameter?

I'm happy to take a stab at such a change if you want me to?

[morgante]

I'd prefer to not remove the create_ssh_key functionality. We can provide ssh_key as an additional option, but for testing/bootstrapping I think the in-module creation is helpful.