How to write an arbitrary blob to a repository to add “supplemental” information, such as contact information or your public GPG key, but without making that blob part of the standard history.
Feed arbitrary text into git hash-object
, and write the corresponding blob to the object store:
echo "Robert P. J. Day" | git hash-object -w --stdin 8a1385ff5d6ab8c195f99931042b7afaf418e6b0 $
$ git show 8a1385ff5d6ab8c195f99931042b7afaf418e6b0 Robert P. J. Day $
In order for that blob not to be garbage-collected, tag it:
$ git tag fullname 8a1385ff5d6ab8c195f99931042b7afaf418e6b0
Show it:
$ git show fullname Robert P. J. Day $
In fact, this technique is used by Git maintainer Junio Hamano to disseminate his public GPG key with the Git source code:
$ git show junio-gpg-pub tag junio-gpg-pub Tagger: Junio C Hamano <gitster@pobox.com> Date: Thu Nov 20 15:12:15 2014 -0800 GPG key to sign git.git archive This blob contains the GPG public key I use to sign git.git archive. To use it to verify tags I signed, do: $ git-cat-file blob junio-gpg-pub | gpg --import to import it into your keyring, and then $ git-tag -v $tag_to_be_verified The fingerprint information for the key is as follows: $ gpg --fingerprint -k 96AFE6CB\! pub 4096R/713660A7 2011-10-01 Key fingerprint = 96E0 7AF2 5771 9559 80DA D100 20D0 4E5A 7136 60A7 uid Junio C Hamano <gitster@pobox.com> uid Junio C Hamano <junio@pobox.com> uid Junio C Hamano <jch@google.com> sub 4096R/833262C4 2011-10-01 sub 4096R/96AFE6CB 2011-10-03 [expires: 2015-09-21] sub 4096R/B3F7CAC9 2014-09-20 [expires: 2017-09-19] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJUbnV7AAoJELC16IaWr+bLvjYP+wSOG8rp1y77ExHDJQj7HBLm 9PVQIb70tkiBxAGUpVNNbaoJQBuMAgFdT4Baj8CIo2jdzDeeqbjtcdy/XsHZ3IMl ... etc etc ...