Idiomatic solution

I'm kind of surprised I didn't come across the subtree solutions when I was writing this script. I did need to deal with the submodules in a couple of specific ways so I probably searched for the wrong words. I like the way this script turned out though, I'll probably keep using it.

git-import

Import one git repository into another, maintaining all commit history.

Usage

From within any git repository, specify a URL or path to another repository that contains the files you want to import and the path in the current repository to put the imported files and history. This can be run from anywhere within your repository.

git-import REPO PATH

• REPO The URL or path to another repository that contains the files you want to import.
• PATH The path in the current repository to put the imported files and history. If PATH doesn't exist it will be created.

If the REPO argument is not a valid git repository, the program will exit.

If the PATH argument is omitted it will default to the name of the imported repository.

If the PATH argument is a path outside of the current repository, the program will exit.

If the PATH argument points to a file or directory that exists, you will be prompted to delete the file/directory. This is irreversible.

If the imported repository has any submodule definitions, for each one you will be prompted to either import it's files and commit history, migrate the submodule definition into the the current repository, or ignore it entirely.

Examples

Here is a very simple example demonstrating how to import a repository:

$ mkdir my-repo

$ cd my-repo
~/my-repo

$ git init
Initialized empty Git repository in ~/my-repo/.git/

$ git log
fatal: your current branch 'master' does not have any commits yet

$ git-import https://github.com/mkenney/git-import.git ./libs/git-import
Validating repository...
Validating url...
Validating path...
Cloning into '/tmp/git-import-1520477002930870000'...
remote: Counting objects: 23, done.
remote: Compressing objects: 100% (6/6), done.
remote: Total 23 (delta 2), reused 0 (delta 0), pack-reused 16
Receiving objects: 100% (23/23), 6.61 KiB | 1.65 MiB/s, done.
Resolving deltas: 100% (7/7), done.
On branch master
Your branch is up to date with 'origin/master'.

nothing to commit, working tree clean
Rewrite 294030e5b3bec09d46b494dbd04f4b35a168d07c (7/7) (0 seconds passed, remaining 0 predicted)
Ref 'refs/heads/master' was rewritten
Updating git-import-1520477002930870000
remote: Counting objects: 32, done.
remote: Compressing objects: 100% (14/14), done.
remote: Total 32 (delta 6), reused 12 (delta 5)
Unpacking objects: 100% (32/32), done.
From /tmp/git-import-1520477002930870000
 * [new branch]      master     -> git-import-1520477002930870000/master
On branch master
nothing to commit, working tree clean

$ git log
commit ddd6af37abff828c2c84089bc289646ebe5a48c3 (HEAD -> master)
Author: Michael Kenney <[email protected]>
Date:   Wed Mar 7 19:46:35 2018 -0700

    cleanup error output

commit 6bc503bebf5fdc543742062b37b8b72603b85daf
Author: Michael Kenney <[email protected]>
Date:   Wed Mar 7 19:46:18 2018 -0700

    add examples

commit ef682fb1df08000e91d617d6f7b1e767db2c6a41
Author: Michael Kenney <[email protected]>
Date:   Wed Mar 7 00:48:03 2018 -0700

    cleanup

commit 388676fa6b45a11d23894bce3de6f1d60a750af3
Author: Michael Kenney <[email protected]>
Date:   Thu Sep 7 19:03:34 2017 -0600

    formatting
...

$