avoid rebuilding node_modules in elastic beanstalk - node.js

Question

We have a fairly simple node.js app, but due to AWS Elastic Beanstalk deployment mechanism, it takes about 5 minutes to roll-out a new version (via git aws.push) even after a single file commit.
I.e. the commit itself (and upload) is fast (only 1 file to push), but then Elastic Beanstalk fetches whole package from S3, unzips it and runs npm install, which causes node-gyp to compile some modules. Upon installation/building completion, Elastic Beanstalk wipes /var/app/current and replaces it with the new app version.
Needless to say, constant node_modules rebuilding is not necessary, and rebuilding that takes 30 seconds on my old Macbook Air, takes >5 mins on a ec2.micro instance, not fun.
I see two approaches here:
tweak /opt/containerfiles/ebnode.py and play with node_modules location to avoid its removal and rebuilding upon deployment.
set up a git repo on Elastic Beanstalk EC2 instance and basically re-write deployment procedure ourselves, so /var/app/current receives pushes and runs npm install only when necessary (which makes Elastic Beanstalk to look like OpsWorks..)
Both options lack grace and are prone to issues when Amazon updates their Elastic Beanstalk hooks and architecture.
Maybe somebody has a better idea how to avoid constant rebuilding of node_modules that are already present in the app dir? Thank you.

Answer 1

Thanks Kirill, it was really helpful !
I'm just sharing my config file for people who just look the simple solution to the npm install. This file needs to be placed in the .ebextensions folder of the project, it is lighter since it doesn't include last version of node installation, and ready to use.
It also dynamically checks the node version installed, so no need for it to be included in the env.vars file.
.ebextensions/00_deploy_npm.config
files:
"/opt/elasticbeanstalk/env.vars" :
mode: "000775"
owner: root
group: users
content: |
export NPM_CONFIG_LOGLEVEL=error
export NODE_PATH=`ls -td /opt/elasticbeanstalk/node-install/node-* | head -1`/bin
"/opt/elasticbeanstalk/hooks/appdeploy/pre/50npm.sh" :
mode: "000775"
owner: root
group: users
content: |
#!/bin/bash
. /opt/elasticbeanstalk/env.vars
function error_exit
{
eventHelper.py --msg "$1" --severity ERROR
exit $2
}
#install not-installed yet app node_modules
if [ ! -d "/var/node_modules" ]; then
mkdir /var/node_modules ;
fi
if [ -d /tmp/deployment/application ]; then
ln -s /var/node_modules /tmp/deployment/application/
fi
OUT=$([ -d "/tmp/deployment/application" ] && cd /tmp/deployment/application && $NODE_PATH/npm install 2>&1) || error_exit "Failed to run npm install. $OUT" $?
echo $OUT
"/opt/elasticbeanstalk/hooks/configdeploy/pre/50npm.sh" :
mode: "000666"
owner: root
group: users
content: |
#no need to run npm install during configdeploy

Answer 2

25/01/13 NOTE: updated scripts to run npm -g version upgrade (only once, on initial instance roll out or rebuild) and to avoid NPM operations during EB configuration change (when app dir is not present, to avoid error and to speed up configuration updates).
Okay, Elastic Beanstalk behaves dodgy with recent node.js builds (including presumably supported v.0.10.10), so I decided to go ahead and tweak EB to do the following:
to install ANY node.js version as per your env.config (including
the most recent ones that are not yet supported by AWS EB)
to avoid rebuilding existing node modules, including in-app
node_modules dir
to install node.js globally (and any desired module as well).
Basically, I use env.config to replace deploy&config hooks with customized ones (see below). Also, in a default EB container setup some env variables are missing ($HOME for example) and node-gyp sometimes fails during rebuild because of it (took me 2 hours of googling and reinstalling libxmljs to resolve this).
Below are the files to be included along with your build. You can inject them via env.config as inline code or via source: URL (as in this example)
env.vars (desired node version & arch are included here and in env.config, see below)
export HOME=/root
export NPM_CONFIG_LOGLEVEL=error
export NODE_VER=0.10.24
export ARCH=x86
export PATH="$PATH:/opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/:/root/.npm"
40install_node.sh (fetch and ungzip desired node.js version, make global symlinks, update global npm version)
#!/bin/bash
#source env variables including node version
. /opt/elasticbeanstalk/env.vars
function error_exit
{
eventHelper.py --msg "$1" --severity ERROR
exit $2
}
#UNCOMMENT to update npm, otherwise will be updated on instance init or rebuild
#rm -f /opt/elasticbeanstalk/node-install/npm_updated
#download and extract desired node.js version
OUT=$( [ ! -d "/opt/elasticbeanstalk/node-install" ] && mkdir /opt/elasticbeanstalk/node-install ; cd /opt/elasticbeanstalk/node-install/ && wget -nc http://nodejs.org/dist/v$NODE_VER/node-v$NODE_VER-linux-$ARCH.tar.gz && tar --skip-old-files -xzpf node-v$NODE_VER-linux-$ARCH.tar.gz) || error_exit "Failed to UPDATE node version. $OUT" $?.
echo $OUT
#make sure node binaries can be found globally
if [ ! -L /usr/bin/node ]; then
ln -s /opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/node /usr/bin/node
fi
if [ ! -L /usr/bin/npm ]; then
ln -s /opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/npm /usr/bin/npm
fi
if [ ! -f "/opt/elasticbeanstalk/node-install/npm_updated" ]; then
/opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/ && /opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/npm update npm -g
touch /opt/elasticbeanstalk/node-install/npm_updated
echo "YAY! Updated global NPM version to `npm -v`"
else
echo "Skipping NPM -g version update. To update, please uncomment 40install_node.sh:12"
fi
50npm.sh (creates /var/node_modules, symlinks it to app dir and runs npm install. You can install any module globally from here, they will land in /root/.npm)
#!/bin/bash
. /opt/elasticbeanstalk/env.vars
function error_exit
{
eventHelper.py --msg "$1" --severity ERROR
exit $2
}
#install not-installed yet app node_modules
if [ ! -d "/var/node_modules" ]; then
mkdir /var/node_modules ;
fi
if [ -d /tmp/deployment/application ]; then
ln -s /var/node_modules /tmp/deployment/application/
fi
OUT=$([ -d "/tmp/deployment/application" ] && cd /tmp/deployment/application && /opt/elasticbeanstalk/node-install/node-v$NODE_VER-linux-$ARCH/bin/npm install 2>&1) || error_exit "Failed to run npm install. $OUT" $?
echo $OUT
env.config (note node version here too, and to be safe, put desired node version in env config in AWS console as well. I'm not certain which of these settings will take precedence.)
packages:
yum:
git: []
gcc: []
make: []
openssl-devel: []
option_settings:
- option_name: NODE_ENV
value: production
- option_name: RDS_HOSTNAME
value: fill_me_in
- option_name: RDS_PASSWORD
value: fill_me_in
- option_name: RDS_USERNAME
value: fill_me_in
- namespace: aws:elasticbeanstalk:container:nodejs
option_name: NodeVersion
value: 0.10.24
files:
"/opt/elasticbeanstalk/env.vars" :
mode: "000775"
owner: root
group: users
source: https://dl.dropbox.com/....
"/opt/elasticbeanstalk/hooks/configdeploy/pre/40install_node.sh" :
mode: "000775"
owner: root
group: users
source: https://raw.github.com/....
"/opt/elasticbeanstalk/hooks/appdeploy/pre/50npm.sh" :
mode: "000775"
owner: root
group: users
source: https://raw.github.com/....
"/opt/elasticbeanstalk/hooks/configdeploy/pre/50npm.sh" :
mode: "000666"
owner: root
group: users
content: |
#no need to run npm install during configdeploy
"/opt/elasticbeanstalk/hooks/appdeploy/pre/40install_node.sh" :
mode: "000775"
owner: root
group: users
source: https://raw.github.com/....
There you have it: on t1.micro instance deployment now takes 20-30 secs instead of 10-15 minutes! If you deploy 10 times a day, this tweak will save you 3 (three) weeks in a year.
Hope it helps and special thanks to AWS EB staff for my lost weekend :)

Answer 3

There's npm package that's overwriting default EB behaviour for npm install command by truncating following files:
/opt/elasticbeanstalk/hooks/appdeploy/pre/50npm.sh
/opt/elasticbeanstalk/hooks/configdeploy/pre/50npm.sh
https://www.npmjs.com/package/eb-disable-npm
Might be better than just copying script from SO, since this package is maintained and probably will be updated when EB behaviour will change.

Answer 4

I've found a quick solution to this. I looked through the build scripts that Amazon are using and they only run npm install if package.json is present. So after your initial deploy you can change it to _package.json and npm install won't run anymore! It's not the best solution but it's a quick fix if you need one!

Answer 5

I had 10+ minute builds when I would deploy. The solution was much simpler than others have came up with... Just check node_modules into git! See http://www.futurealoof.com/posts/nodemodules-in-git.html for the reasoning