Add env for branch to use

README.md

@@ -31,6 +31,10 @@ If you specify a SSH URL (`ssh:// ...`) for your repository, the host key will b
 
 If you want to pull private repositories, you may need to generate a SSH key for this purpose, and hand in the private key file, e.g. via `-v ./id_rsa:/root/.ssh/id_rsa`.
 
+#### Specify branch
+
+If there is a specific branch to use (other than [master/main](https://about.gitlab.com/blog/2021/03/10/new-git-default-branch-name/)), you can specify the desired branch using the `REPO_BRANCH` environment variable.
+
 ### Passthrough via Bind
 
 To just use a specific directory as the hugo blog contents, run the container with the repository passed through as bind directory:

aux/pull-n-build.sh

@@ -17,7 +17,11 @@ set -e -v
 		# repo URL set
 		if [ ! -d /repo ]; then
 			# repo needs to be cloned
-			git clone --recurse-submodules $REPO_URL /repo
+			# check if there is a specific branch to clone
+			if [ ! "$REPO_BRANCH" == "" ]; then
+				BRANCHCMD="--branch $REPO_BRANCH"
+			fi
+			git clone --recurse-submodules $BRANCHCMD $REPO_URL /repo
 		else
 			# no - pull existing repo
 			cd /repo && git pull --recurse-submodules