Steps to sign your commits to Gerrit:

0.) Generate your GPG key. See:
    https://lists.opendaylight.org/pipermail/tsc/2015-April/002841.html
    Note: the *s around the non commented lines are just to indicate
          it's a command at the CLI.

0.5) Install gpg, instead of or addition to gpg2. It appears as though
     gpg2 has annoying things that it does when asking for your
     passphrase, which I haven't debugged yet.
     Note: you can tell git to use gpg by doing:
           git config --global gpg.program gpg2
           but that then will seem to struggle asking for your
           passphrase unless you have your gpg-agent set up right.

1.) Add you GPG to Gerrit
    a.) https://git.opendaylight.org/gerrit/#/settings/gpg-keys
    b.) gpg --export -a <fingerprint> // e.g., gpg --export -a F566C9B1
    c.) copy that output and paste it into the box and click add

3.) Set up your git to sign commits and push signatures
    a.) git config commit.gpgsign true
        Note: you can do this instead with git commit -S
    b.) git config push.gpgsign true
        Note: you can do this instead with git push --signed
    c.) git config user.signingkey <fingerprint>
        // e.g., git config user.signingkey F566C9B1

4.) Commit and push a change
    a.) change a file
    b.) git commit -asm "test commit"
        Note: this should result in git asking you for your passphrase
    c.) git review
        Note: this should result in git asking you for your passphrase
        Note: annoyingly, the presence of a gpgp signature or pushing
              of a gpg signature isn't recognized as a "change" by
              Gerrit, so if you forget to do either, you need to change
              something about the commit to get Gerrit to accept the
              patch again. Slightly tweaking the commit message is a
              good way.
        Note: this assumes you have git review set up and push.gpgsign
              set to true. Otherwise:

              git push --signed gerrit HEAD:refs/for/master
              Note: this assumes you have your gerrit remote set up, if
                    not it's something like:
                    ssh://ckd@git.opendaylight.org:29418/<repo>.git
                    where repo is something like docs or controller

5.) Verify that your commit is signed by going to the change in Gerrit
    and checking for a green check (instead of a blue ?) next to your
    name.