Automated Node.js application deployment using git and nvm

post-receive

#!/usr/bin/env sh

set -e

read sha1_old sha1_new refname

WORK_TREE=/srv/admin/apps/si-mysql-maint
NVM="${HOME}/.nvm/nvm.sh"

mkdir -p ${WORK_TREE}
git --work-tree=${WORK_TREE} clean -fd
git --work-tree=${WORK_TREE} checkout ${sha1_new} --force

if [ -s ${NVM} ]; then
        cd ${WORK_TREE}
        NVM_DIR=`dirname ${NVM}`
        export NVM_DIR
        . ${NVM}
        npm install
fi

Specifying ${sha1_new} to git checkout lets you checkout branches and tags.
Don't know why I couldn't find this solution reported. It works. Any downside?