[platform-dev] Moving bundles with history from a Git repo to another

[Mickael Istria <mistria@xxxxxxxxxx>]

Hi all,

I've been asked a couple times how to migrate some folders (eg bundles) from a Git repository to another, and this preserving the history.

While I don't remember the exact details, here are the steps I've carried on:

* from the *source* Git repo

  ** Make sure you're on latest master

  ** use "git filter-repo" (from https://github.com/newren/git-filter-repo/ ) to just keep the subpart of the repository you need, basically passing the directories you want to keep

  ** check the content of the repo on the filesyste,

  ** check `git history` for a long time, to ensure that history seems to contain relevant things only and that the history seems complete (basically the 1st commit of legacy history is still visible -with a different hash though- in the filtered history)

   ** `git push myFork HEAD:refs/heads/filtered-repo`

* From the *target* repo

   ** Make sure you're on latest master

   ** add your local fork of source repo as remote `git remote add myForkOfSourceRepo git://github.com/me/sourceRepo`

   ** `git fetch myForkOfSourceRepo filtered-repo`

   ** `git merge --allow-unrelated-history FETCH_HEAD` (leave default merge commit and message)

   ** Fix various pom.xml, bump versions.,, as needed until local build work

   ** `git add ` changes then `git commit -m "Adapt releng for move of X, Y, Z from sourceRepo`

   ** Push to your fork

   ** Create a PR

* From the source repo

   ** Get back to latest master

   ** Remove all moved content

   ** Adapt pom.xml and so on until build works

   ** Commit

   ** Create PRs

* On each of both PRs, add a link to the other one, as they will need to be merged at the same time

* Once PRs are merged, trigger an I-Build and hope for a successful build in the next 40 minutes; or fix.

HTH

--

Mickael Istria

Eclipse IDE developer, for Red Hat