This tutorial assumes that you are using a restricted-access environment, with limited or no internet access. It will describe how to synchronize a repository INSIDE with the repository OUTSIDE, which may be on Github, Bitbucket, or Gitlab.

 +------------------+          ||          +---------------+
 |    git (cloned)  |          ||          |  git (cloned) |
 |                  |   =====> || ========>|               |   ========> [ Github ]
 |   I N S I D E    |          ||          | O U T S I D E |          
 +------------------+          || Firewall +---------------+

Setup OUTSIDE

• Set up a new OUTSIDE repository - for discussion's sake, create a README.
• On an outside system, clone that repository (follow the instructions on Github/Gitlab/etc. when creating the repository). Do not add any files to it.

Setup INSIDE

On the INSIDE, initialize a Git repo for offline access (ref1, ref2)

mkdir myproj
cd myproj
echo "Hello" > README.md
git init
git add README.md
git commit -m "first commit"

Now we want to git bundle this repo (we also create a tag, to flag which version we did here)

git bundle create file.bundle master
git tag -f lastOUTSIDEbundle master

Now the file file.bundle can be moved _somehow _to the OUTSIDE system (e.g., email, sftp by authorized users, etc.). The example below assumes somebody has scp access to the system.

> scp INSIDE:/path/from/file.bundle OUTSIDE:/path/to/file.bundle

On the OUTSIDE system, edit the $GIT_DIR/config file (usually in the .git directory), and add the following entry:

[remote "bundle"]
    url = /path/to/file.bundle
    fetch = refs/heads/*:refs/remotes/origin/*

Now, to update the repo on OUTSIDE, you call

git pull bundle

NOTES

• it may be more useful to use a branch on OUTSIDE that tracks the INSIDE system, whereas master tracks the Github
• this needs to be tested.