how can I add git submodule into git repo as normal directory?

Question

Let's see what it is

• Create two git repo sub & test

mkdir test sub
cd test && git init && touch README && git add README && git commit -m "initialize the git repo" && cd ..
cd sub && git init && touch README && git add README && git commit -m "initialize the sub git repo" && cd ..

• Move the sub repo into test

mv sub test
cd test 
git add sub
git commit -m "add sub directory"

I want to treat them as one git repo and push them remotely, but now the files under sub directory can not be included ?

How can I achieve this in simple way like treat sub as normal directory ?

Use case for this

I try to add my jenkins data folder (JENKINS_HOME) into docker images using Dockerfile for demo. (ADD JEKINS_HOME /opt/jenkins)

JENKINS_HOME
Dockerfile

My jenkin has scriptler plugin which contains the git repo for its purpose. Then it exists in my docker image git repo like below

$ find jenkins-docker
./.git
./.git/.. (skipped
./Dockerfile
./JENKINS_HOME
./JENKINS_HOME/scriptler
./JENKINS_HOME/scriptler/scripts
./JENKINS_HOME/scriptler/scripts/.git
./JENKINS_HOME/scriptler/scripts/.git/... (skipped)
./JENKINS_HOME/scriptler/scripts/Sample.groovy
./JENKINS_HOME/... (skipped)
./README

Answer 1

Seems you cannot do that. The name .git is hard-coded in the source code: https://github.com/git/git/blob/fe9122a35213827348c521a16ffd0cf2652c4ac5/dir.c#L1260

Probably one way is to make a script which renames .git to something else and back before and after adding it into repo like

In working directory under scripts

mv .git hidden-git

In Dockerfile

RUN mv $JENKINS_HOME/scriptler/scripts/hidden-git     
$JENKINS_HOME/scriptler/scripts/.git

Alternatively, probably it's possible to pass GIT_DIR environment variable into the plugin, so it could use another name.

Answer 2

git add sub
git commit -m "add sub directory"

I want to treat them as one git repo and push them remotely, but now the files under sub directory can not be included ?

They are not included because test sees repo sub as nested git repo, and records only its gitlink, or SHA1, and not its url as it would have if sub had been added as a submodule.

You would need to push sub to a remote url first, and then add it as submodule for test to see sub files.

 cd test
 git submodule add -- /url/to/sub

Or you would need to use a subtree

cd test
git subtree --prefix sub /url/to/sub master --squash