Blizzardengle Blizzardengle - 2 months ago 5x
Git Question

Git - How to auto push changes in a directory to another branch

Complete question rewrite

So I thought I was explaining this question very simply and direct but it seems I oversimplified to much, so here is all the extra details. Hopefully this helps everyone see this is also not a duplicate.

I have a repository (project) where I would like to automate the process of pushing commits from one directory in a branch to another branch; something I have not come across yet on SO.

Here is my project with its complete structure:

|- gh-pages (directory)
|- css (directory)
|- index.html (file)
|- (file)

|- (empty at the moment)

What I am hoping to do is create a hook that will automatically handle changes in my gh-pages directory from the master branch, and copy/ clone/ replace them (whichever term is correct to use) into by gh-pages branch, the projects website branch. Here is an example with all other files left out:

|- gh-pages (directory) <=== SEE UPDATE BELOW [A]
| |- css (directory)
| | |- style.css (file)
| |- index.html (file)

|- css (directory) <=== SEE UPDATE BELOW [B]
| |- style.css (file)
|- index.html (file)

I am completely new to this level of Git Hub. I normally just stick to the basics and never use the terminal/ shell. So in summary to clarify what I am hoping to do, I would like to:

  • Only have to work in the [Master Branch]. All changes I need to make to [gh-pages Branch] I do in the gh-pages directory of [Master Branch]

  • Preferable accomplish this by adding a simple file which seems to be a post-receive hook?

Here is some post-receive hook code that I tried using (I made it from studying a few things) but it doesn't work:

while read oldrev newrev refname
branch=$(git rev-parse --symbolic --abbrev-ref $refname)
if [ "master" == "$branch" ]; then
git checkout gh-pages
git checkout master -- gh-pages
git add gh-pages
git commit -m "Updating project website from 'master' branch."


As mentioned in my comment: This is not a duplicate. This is not asking how to push but rather how to tack on other commands that auto run when I do a normal push. These commands would do the extra work mentioned in my OP.


I have added these arrows to parts of my code I refer to below: <===

[A] What should happen here is that Git should recursively read the master branches gh-pages directory and only copy from that what has updated (or everything if that is easier) into the gh-pages branch.

[B] So if the gh-pages directory in master has an index.html file and a css folder with a style.css file is should only copy over that structure not the gh-pages directory itself. Below is an example of a bad hook that copies the gh-pages directory too:

|- gh-pages (Directory) <=== NOT SUPPOSED TO HAPPEN
| |- css (directory)
| | |- style.css (file)
| |- index.html (file)

Also, the hook should not copy over any other files but what is inside the gh-pages. Even if several other files changed in the master branch only the gh-pages directory files should be copied over.

[C] NEW CODE - This works but causes an error:

branch=$(git rev-parse --abbrev-ref HEAD)
if [ "master" == "$branch" ]; then
git fetch && git checkout gh-pages
git checkout master -- gh-pages/*
git add -A
git commit -m "Updating project website from 'master' branch."
git push -u origin gh-pages

This wont work for two reasons. 1) If the repo is behind on commits it cant handle that, it will error out; if a pull is used instead of a fetch the local repo gets wiped like so:

Local repo has been wiped when changing code to pull.

If I leave fetch the local repo stays the way it should:

Local repo the way it should stay after a push. Fetch was used here.

2) The whole gh-pages directory gets copied over to the gh-pages branch still and not just the files inside it.


You really don't need this complex approach.

Simply add your own repo as a submodule (of itself!), submodule following the gh-pages branch (since a submodule can follow the latest commit of a branch)!

git checkout master
git rm -r gh-pages # save your data first
git submodule add -b gh-pages -- /remote/url/of/your/own/repo
git commit -m "ADd gh-pages branch as submodule"
git push

That way, you can change files either in your main branch, or in the gh-pages folder (which is actually a submodule)

Whenever you are making changes in gh-pages folder, don't forget to commit there, and in the main folder of your repo in order to record the new gitlink (special entry in the index) reprsenting the new SHA1 of the gh-pages submodule.

cd myrepo/gh-pages
# modify files
git add .
git commit -m "modify gh-pages files"
cd .. # back to myrepo folder
git add gh-pages
git commit -m "record gh-pages new SHA1"
git push

With git 2.7+, you can set:

cd /path/to/main/repo
git config push.recurseSubmodules on-demand

Then a single git push from your main repo will also push the gh-pages submodule to the gh-pages branch.

Later, a single git clone would clone both your main repo and its gh-pages branch (in the gh-pages submodule folder).

That way, you always have both content visible.

And you don't need a complex "synchronization/copy" mechanism.

Update August 2016: Simpler GitHub Pages publishing now allows to keep your page files in a subfolder of the same branch (no more gh-pages needed):

Now you can select a source in your repository settings and GitHub Pages will look for your content there.

You don't need the submodule approach anymore, since your pagers can be in a subfolder within the same branch.