eic_curl_authorized_keys returns incorrect exit code in some cases

[pagelypete]

In this section of the code curl is called with -f which causes it to return exit code 22 when the HTTP response code is >= 400. This means that when the user doesn't have any keys for example, and the metadata service returns 404, the script exits with code 22 due to the set -e in the script.

I discovered this when calling eic_run_authorized_keys as an additional fallback for my AuthorizedKeysCommand script, I was executing:

exec /usr/share/ec2-instance-connect/eic_run_authorized_keys "${@}"

Which would then cause my own script to return exit code 22, and thus no keys produced by the calling script were accepted at all either due to the non-zero code.

I am filing a bug because the logic in the script shows an intention for this to be an exit 0 scenario.