Permission denied (publickey) when running docker run mozilla/mozilla-schema-generator

[acmiyaguchi]

$ export MPS_SSH_KEY_BASE64=$(cat ~/.ssh/id_rsa | base64)
$ docker run mozilla/mozilla-schema-generator
...
+ clone_and_configure_mps
+ [[ -d mozilla-pipeline-schemas ]]
+ git clone git@github.com:mozilla-services/mozilla-pipeline-schemas.git
Cloning into 'mozilla-pipeline-schemas'...
Warning: Permanently added the RSA host key for IP address '192.30.253.113' to the list of known hosts.
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

This does not happen when running make build && make run.

[acmiyaguchi]

I no longer run into this issue.