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This is part of implementation for issue https://gitlab.com/gitlab-org/gitlab-ce/issues/18266

See merge request !77

update spec

different text for new and existing merge request

update spec

fix style

switch order of messages

enhance message appearance

remove extra spaces

Update the keys permission check to open the file in write mode.

That way the file is created if it does not exist.

This will help simplify the check being running from omnibus. Currently we create the authorized_keys, file in omnibus. We want to instead have omnibus call check-permissions as the git user, to get around nfs root_squash issues with the authorized_keys file.

See merge request !83

That way the file is created if it does not exist.

Defense in depth for authorized_keys lines

Validate the key_id and public_key inputs when rendering the actual
'line' we append to authorized_keys. Although these inputs are either
trusted (key_id) or validated earlier (public_key) it does not hurt to
take a little extra care that we do not write unintended data to the
authorized_keys file.

See merge request !82

Small improvements

- refactor GitlabKey away
- fix Redis check output

See merge request !81