Using a GIT-hook to deploy blog

So after getting bored by deploying the blog to the server. I came to the conclusion that this can probably be done in a more efficient manner. After some looking around I decided to try to use a git hook to do it. Also spent some time with this book¹ in the weekend

The setup is the following A --> B --> C where A is the computer where I do the editing, B is the computer hosting my bare git repo, and C is the web-server hosting this page. The web-page is made with hugo.

I found script² on the internet i will base my work on.

The most promising hook seems to post-receive, since it executes once for the receive operation. Getting the hook to run was simple. Just name it post-receive place it in the hooks directory (on the git server) and set the executable bit chmod +x

However to be able to understand what the script is doing (or let’s say debug it) I added a lot of echo "XYZ" >> hooks.log to the script

The plan is to not have a git on the web-server, but rather make git server at home upload it to the external web-server

Using³ as base of operations and giving up on understanding bash black magic… (Maybe the next post?)

Ran in to a bunch of trouble with running git archive HEAD giving me the error fatal: not a valid object name: HEAD after some googling i found the command git symbolic-ref HEAD that showed the path refs/heads/main but the file didn’t exist! It was named refs/head/master.

So a name change of the master-branch to main solved it git branch -m master main and the then a git push origin HEAD got the data to the server. Then some issues arises with naming and that I had both master and main branch on remote.

git push origin -d master deleted the master branch git branch --unset-upstream made my local repo to stop complaining.

And so the complete script is done, it now deploys the site to the web.

Hold on, why do I get build errors from the hugo build? Turns out the sub-modules are not archived with git archive. That’s not a problem we have git submodule foreach⁴ you would think that this can work: git submodule foreach --recursive 'git archive --verbose --prefix=repo/$path/ --format=tar main It works perfectly on on your local repo but not on a bare server repo..

git submodule foreach that gives me an error about no git-tree. My assumption is that is because its a bare repository. I have to this point not found a solution to this issue yet. Any suggestions? please e-mail me.

So how can the same functionally be solved in a much less elegant way? You guess it, git clone that will always give me the latest template so the I need to remember to always update the sub-module on my local machine when doing development. I wouldn’t suggest this for a production environment where bugs in production cannot happen.

And yes the the script could be more elegantly written.

#!/bin/bash
BRANCH="main"
while read oldrev newrev ref
do
if [ "$ref" = "refs/heads/$BRANCH" ];
then
	temp_dir=$(mktemp -d) || { echo "Failed to create tmp directory"; exit2;}
	git archive --format=tar --output="$temp_dir/web.tar" HEAD
	cd "$temp_dir"
	tar xf web.tar
	cd "$temp_dir/themes"
	rm -rf hugo-coder
	git clone https://github.com/luizdepra/hugo-coder.git
	cd "$temp_dir"
	hugo
	# Do your transport magic here... 
	rm -rf "$temp_dir"
	echo "Deployment done"
else
	echo "Do nothing"
fi
done