Assume you want to transfer the history from a repository R1 on machine A
to another repository R2 on machine B.
For whatever reason, direct connection between A and B is not allowed,
but we can move data from A to B via some mechanism (CD, email, etc.).
We want to update R2 with development made on the branch master in R1.
To bootstrap the process, you can first create a bundle that does not have
any prerequisites. You can use a tag to remember up to what commit you last
processed, in order to make it easy to later update the other repository
with an incremental bundle:
machineA$ cd R1
machineA$ git bundle create file.bundle master
machineA$ git tag -f lastR2bundle master
Then you transfer file.bundle to the target machine B. Because this
bundle does not require any existing object to be extracted, you can
create a new repository on machine B by cloning from it:
machineB$ git clone -b master /home/me/tmp/file.bundle R2
This will define a remote called "origin" in the resulting repository that
lets you fetch and pull from the bundle. The $GIT_DIR/config file in R2 will
have an entry like this:
[remote "origin"]
url = /home/me/tmp/file.bundle
fetch = refs/heads/*:refs/remotes/origin/*
To update the resulting mine.git repository, you can fetch or pull after
replacing the bundle stored at /home/me/tmp/file.bundle with incremental
updates.
After working some more in the original repository, you can create an
incremental bundle to update the other repository:
machineA$ cd R1
machineA$ git bundle create file.bundle lastR2bundle..master
machineA$ git tag -f lastR2bundle master
You then transfer the bundle to the other machine to replace
/home/me/tmp/file.bundle, and pull from it.
machineB$ cd R2
machineB$ git pull
If you know up to what commit the intended recipient repository should
have the necessary objects, you can use that knowledge to specify the
prerequisites, giving a cut-off point to limit the revisions and objects that go
in the resulting bundle. The previous example used the lastR2bundle tag
for this purpose, but you can use any other options that you would give to
the git-log(1) command. Here are more examples:
You can use a tag that is present in both:
$ git bundle create mybundle v1.0.0..master
You can use a prerequisite based on time:
$ git bundle create mybundle --since=10.days master
You can use the number of commits:
$ git bundle create mybundle -10 master
You can run git-bundle verify to see if you can extract from a bundle
that was created with a prerequisite:
$ git bundle verify mybundle
This will list what commits you must have in order to extract from the
bundle and will error out if you do not have them.
A bundle from a recipient repository’s point of view is just like a
regular repository which it fetches or pulls from. You can, for example, map
references when fetching:
$ git fetch mybundle master:localRef
You can also see what references it offers: