Git hooks for deploying a Django application.

post-receive

#! /bin/bash

# CONSTS:
# Which server prefix should be used for this post-recieve hook
SERVER="production"

# Which port the local gunicorn instance should use (need to use a different
# port per server).
PORT=8001


# Checkout a new version of the code
#
# We checkout a fresh version of the code in /home/git/tmp every time we
# get a commit pushed to this server. Once we checkout the new version
# we copy it over to the virtual environment (specified by our server).
function checkout() {
        local checkout_status=
        local copy_status=

        GIT_WORK_TREE=/srv/git/tmp git checkout -f
        checkout_status=$?

        if [ $checkout_status -eq 0 ]; then
                echo "successfully checked out the repository"
        else
                echo "failed to checkout fresh repository, aborting..."
                return 1
        fi

        cp -r /srv/git/tmp/* /srv/www/${SERVER}/kcdc/kcdc3
        copy_status=$?

        if [ $copy_status -eq 0 ]; then
                echo "successfully copied the repository to the virtual env"
        else
                echo "failed to copy to the repository virtual env, aborting..."
                return 1
        fi
}

# Starts Gunicorn
#
# We log into our virtual env and startup the middleware so we can start
# handling requests!
function gunicorn() {
        # This pid file holds the parent pid of all of the gunicorn instances
        local gunicorn_pid="/srv/www/${SERVER}/kcdc/srv/gunicorn.pid"

        local kill_status=
        local gunicorn_status=

        pushd /srv/www/${SERVER}/kcdc
        source bin/activate

        if [ -e "$gunicorn_pid" ]; then
                kill $( cat $gunicorn_pid )
                rm $gunicorn_pid
        fi
        kill_status=$?

        if [ $kill_status -eq 0 ]; then
                echo "successfully killed the existing gunicorn process"
        else
                echo "failed to kill the exitsing gunicorn process, aborting..."
                return 1
        fi

        python kcdc3/manage.py run_gunicorn \
                --workers=4 \
                --daemon \
                --pid=/srv/www/${SERVER}/kcdc/var/gunicorn.pid \
                --access-logfile=/srv/www/${SERVER}/kcdc/var/access.log \
                127.0.0.1:${PORT}
        gunicorn_status=$?

        if [ $gunicorn_status -eq 0 ]; then
                echo "successfully started gunicorn"
        else
                echo "gunicorn failed, aborting..."
        fi

        deactivate
        popd
}

# Where the magic happens
function main() {
        # Checkout stage
        local checkout_status=

        checkout
        checkout_status=$?

        if [ $checkout_status -ne 0 ]; then
                return 1
        fi

        # Gunicorn stage
        local gunicorn_status=

        gunicorn
        gunicorn_status=$?

        if [ $gunicorn_status -ne 0 ]; then
                return 1
        fi
}

main