Pull repositories from a monorepo in parallel

gs-pull-parallel

#!/bin/bash
PARALLEL=${1:-5}

directories=()
for dir in */ ; do
    if [ -e "$dir/.git" ] ; then
        directories+=("$dir")
    fi
done

parallel_pull() {
    dir=$1
    echo "Updating $dir"
    cd "$dir" || exit
    current_branch=$(git rev-parse --abbrev-ref HEAD)
    if git status --porcelain | grep -q "^ M"; then
        echo "Stashing local changes in $dir"
        git stash push --include-untracked --message "Local changes stashed by update script"
        git fetch -q origin master:master
        git stash pop
    else
       git fetch --all
    fi
    git checkout -q "$current_branch"
    cd ..
}

export -f parallel_pull

printf '%s\0' "${directories[@]}" | xargs -0 -n 1 -P "$PARALLEL" bash -c 'parallel_pull "$@"' _

TODOs

handle the different scenario:

• master no local changes
• master with local changes
• different branch no local changes
• different branch with local changes

join the forked processes as well => otherwise one might get a prompt while some jobs are still running in the background - there are some bash whistles to use here