Using git-submodules to version-control Vim plugins

If you work across many computers (and even otherwise!), it's a good idea to keep a copy of your setup on the cloud, preferably in a git repository, and clone it on another machine when you need. Thus, you should keep the .vim directory along with your .vimrc version-controlled.

But when you have plugins installed inside .vim/bundle (if you use pathogen), or inside .vim/pack (if you use Vim 8's packages), keeping a copy where you want to be able to update the plugins (individual git repositories), as well as your vim-configuration as a whole, requires you to use git submodules.

Creating the repository

Initialize a git repository inside your .vim directory, add everything (including the vimrc), commit and push to a GitHub/BitBucket/GitLab repository:

cd ~/.vim
cp ~/.vimrc vimrc
git init
git add *
git commit -m "Initial commit."
git remote add origin https://github.com/username/reponame.git
git push -u origin master

To enable submodules:

cd ~/.vim
git submodule init

Installing plugins

To install plugins (say always-loaded foo and optionally-loaded bar, located at https://github.com/manasthakur/foo and https://github.com/manasthakur/bar, respectively) using Vim 8's package feature:

git submodule add https://github.com/manasthakur/foo.git pack/plugins/start/foo
git submodule add https://github.com/manasthakur/bar.git pack/plugins/opt/bar
git commit -m "Added submodules."

Replicating the repository on a machine

Clone the repository (recursively to clone plugins as well):

git clone --recursive https://github.com/username/reponame.git

Symlink .vim and .vimrc:

ln -sf reponame ~/.vim
ln -sf reponame/vimrc ~/.vimrc

Generate helptags for plugins:
```
vim
:helptags ALL
```

Removing plugins

To remove foo:

cd ~/.vim
git submodule deinit pack/plugins/start/foo
git rm -r pack/plugins/start/foo
rm -r .git/modules/pack/plugins/start/foo

Updating plugins

To update foo:

cd ~/.vim/pack/plugins/start/foo
git pull origin master

It is recommended to first git fetch origin master a plugin, review changes, and then git merge.

To update all the plugins:

cd ~/.vim
git submodule foreach git pull origin master

Note that new commits to plugins create uncommitted changes in the main repository. Thus, after any updates in the submodules, you need to commit the main repository as well:

cd ~/.vim
git commit -am "Updated plugins."

On another machine, if a git pull for the main repository leads to uncommitted changes in the submodules (as a few plugins got updated), perform git submodule update to change the recorded state of the submodules.

Even though slightly complicated, submodules are a necessary devil when you want to maintain an easily-cloneable .vim repository. The other option is to not version-control submodules at all by adding a line pack in ~/.vim/.gitignore, and manually add plugins on a new machine.