Commit .git folder from subfolder in git repository

Below is structure of git repository which has another git repository initialized using git init in subfolder dir.

$ tree -a -L 2 . 
.
├── .git
│   ├── HEAD
│   ├── config
│   ├── description
│   ├── hooks
│   ├── info
│   ├── objects
│   └── refs
└── dir
    └── .git

How to commit and push .git folder from the subfolder?

I tried running git add dir/.git and git commit .., but nothing was commited as far as git log is concerned.

Repository inside dir is used in deployment by some tool which needs to clone/checkout changes from local git repository in dir.

Solution

Using git submodules according to tutorial helped.

Below sequence of commands illustrates the required test flow:

$ mkdir git_repo
$ cd git_repo/
$:git_repo  git init
Initialized empty Git repository in /private/tmp/git_repo/.git/
$:git_repo  mkdir inner_repo
$:git_repo  cd inner_repo
$:inner_repo  git init
Initialized empty Git repository in /private/tmp/git_repo/inner_repo/.git/
$:inner_repo  touch file
$:inner_repo  git add file
$:inner_repo  git commit -m 'initial'
[master (root-commit) 2b13943] initial
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 file
$:inner_repo  cd ..
$:git_repo  git submodule add ./inner_repo
Adding existing repo at 'inner_repo' to the index
$:git_repo  cd ..
$ git clone git_repo/inner_repo inner
Cloning into 'inner'...
done.

Below flow achieved the desired result in existing local repository which had remote in Bitbucket:

create folder for inner repository in parent repository
copy some files to inner_repo
initialize inner repository and commit the files (inside inner_repo run git init and git commit -am 'initial')
go to parent repo: cd ...
critical step: git submodule add ./inner_repo ./inner_repo

After that .gitmodules and inner_repo were staged.

Explanation according to docs:

git submodule add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]

Add the given repository as a submodule at the given path to the changeset to be committed next to the current project: the current project is termed the "superproject".

The optional argument <path> is the relative location for the cloned submodule to exist in the superproject. If <path> exists and is already a valid Git repository, then it is staged for commit without cloning.