[BUG] "Error creating signature: No pinentry"

[git-hyagi]

Describe the bug
Configuring signing services with a passphrase in the gpg key will fail with:

Traceback (most recent call last):
  File "/usr/bin/pulpcore-manager", line 33, in <module>
    sys.exit(load_entry_point('pulpcore==3.23.2', 'console_scripts', 'pulpcore-manager')())
...
    signed = self.sign(
  File "/usr/lib/python3.9/site-packages/pulpcore/app/models/content.py", line 807, in sign
    raise RuntimeError(str(completed_process.stderr))
RuntimeError: b'time="2023-06-29T16:26:58Z" level=fatal msg="Error creating signature: No pinentry"\n'

To Reproduce
Steps to reproduce the behavior:
Follow the steps from https://github.com/pulp/pulp-oci-images/blob/latest/docs/signing_script.md, but in the Creating a gpg key step, define a passhrase (instead of passing the %no-ask-passphrase parameter).

[mikedep333]

FYI: The example script shows a password inside the script, but it does not work successfully.

We are going to assume users will set the PASSWORD env variable separately for a real secure solution, we just need to make the example script work.

And the solution to making the example script work seems to be to install the pinentry package. Specifically, it seems to make gpg --passphrase work.

[Janr2]

Just a note.

This worked for me without the package.

gpg --pinentry-mode loopback etc .....