Just as a kind of mini cheat sheet for using git tags. Jörg Mittag had some great additions that weren’t in the original post which warrant a new post.
Git has three different type of tags:
- Lightweight tags
- Annotated tags
- Signed tags
Let’s start with lightweight tags.
In the previous cheat sheet only the lightweight local tags were discussed. A lightweight tag is nothing more than a reference to a particular revision or SHA1 object name in the repository. This kind of tag is quick and easy and very usable for local development to mark places in your commit history.
Creating a lightweight tag is easy:
git tag tag_name
Viewing available tags is done with
git tag -l
Annotated tags are almost like lightweight tags, the big difference is that they contain a message. Normally this message indicated why this tag is interesting. Use the
-a option to create an annotated tag.
git tag -a tag_name
Since a message is required for annotated tags, you will be prompted with an editor to enter a message, or you can use the
-m option to specify one directly.
git tag -a -m “Tagging release 1.0” v1.0
To view annotated tags you can use the same
-l option as before, but you have to instruct git to show the annotation messages as well:
git tag -l -n1
This will not only show the messages for the annotated tags, it will also show the commit message of the revisions tagged with lightweight tags as well. Quite useful!
Signed tags take annotated tags a step further, they include an OpenPG signature to provide trust. While gits SHA1 tags provide integrity for the repository, the OpenPG signature makes sure that a trustworthy person created the tag.
To create a signed tag you’ll need to have GPG or some other OpenPG tool setup and use the
-s option to sign the tag:
git tag -s -m “Tagging release 2.0” v2.0
-s options implies the
-a option, so here too a message is required.
To verify a signed tag you can run the following:
git tag -v v2.0
There are times when you want to remove tags as well. This quite easy:
git tag -d tag_name
To remove a tag on a remote repository, you should do a special push:
git push origin :refs/tags/tag_name
Jörg Mittag claims that annotated and signed tags are pushed and fetched automatically. I have never seen a tag of any kind being pushed automatically, so I hope Jörg can clarify this further.
To push your tags to a remote repository, use the following command to push all tags:
git push origin –tags