I have four OpenPGP keys, I need to sign the Ubuntu Code of Conduct with a specific OpenPGP key. How do I make one of the OpenPGP key is default so I can sign the code with that key?
Signing the Ubuntu Code of Conduct
The general signing procedure is described in Ubuntu's GnuPG how-to. It boils down to performing a clear-text signature of a text document:
gpg --clearsign UbuntuCodeofConduct-2.0.txt
Selecting a Specific Key for Signing
To sign using a specific key, you need to tell GnuPG which one to use. From
--clearsign Make a clear text signature. The content in a clear text signature is readable without any special software. OpenPGP software is only needed to verify the signature. Clear text signatures may modify end-of-line whitespace for plat- form independence and are not intended to be reversible. The key to be used for signing is chosen by default or can be set with the --local-user and --default-key options. [snip] --local-user name -u Use name as the key to sign with. Note that this option overrides --default-key.
The changed clearsign command form above is:
gpg --local-user [key-id] --clearsign UbuntuCodeofConduct-2.0.txt
Setting a Persistent Default Key
This just modifies the behavior for the current call of GnuPG. To set a default key (which can still be overridden using
default user [key-id] in