Node.js, Vagrant, Chef, and Mathoid @ Benetech

Node.js, Vagrant, Chef, and Mathoid @ Benetech

• 1.
  Node.js with Vagrantand Chef @ Benetech April 24, 2014 Chris Bumgardner
• 2.
  Why Vagrant?  Speedand Portability  Get a working uniform development environment running in about 15 minutes while getting a coffee.  This often takes hours or days for a modern environment getting specific libraries, tools, and versions for a specific operating system.  Open source and mature. Around since 2010.
• 3.
  Advantages to aVM Image  Vagrant is small: just text files in source control  A snapshot is typically around 0.5GB – 1GB. Hard to host and transfer.  A snapshot is binary: changing a version of a library is hard, but in Vagrant it is just a configuration change.  Abstraction: Vagrant can run on top of different providers, such as AWS, Docker or Azure in addition to a local virtual machine.  https://github.com/mitchellh/vagrant-aws  https://github.com/10thmagnitude/vagrant-azure
• 4.
  Installing Vagrant &VirtualBox  Install Vagrant here: http://www.vagrantup.com/downloads.html  Install VirtualBox here: https://www.virtualbox.org/wiki/Downloads  Cloud boxes are automatically downloaded and installed with Vagrant 1.5+  Be sure to upgrade Vagrant if you have an older version.
• 5.
  Configuration Management viaChef  Idempotent  You can run Chef multiple times on the same system with identical results.  Not the case with shell scripts: running more than once will usually lead to unpredictable results.  Cross-platform  Chef supports Linux, Mac, Windows  Shell scripts are system dependent  Existing ecosystem of cookbooks: don’t reinvent the wheel.  Chef Solo: runs on local machine, does not require server infrastructure.
• 6.
  Docker, Packer, etc:More DevOps  DevOps tools appear daily.  Chef alternatives: Puppet, Ansible, Salt, etc.  Docker.io  Promising tool that contains and virtualizes processes.  Think of Vagrant but for a specific process.  Example: turn a server application into a portable image.  Packer.io  Automates creation of machine images.  A meta layer above a tool like Vagrant.
• 7.
  Mathoid using Vagrant https://github.com/cbumgard/mathoid-vagrant  Once running you can access at localhost:10042  Built on Ubuntu Precise 12.04 64-bit base box. Found 14.04 not compatible yet with Mathoid.  First time you “vagrant up” it has to download the base box (~300MB). Boxes are cached locally however.  Added Chef cookbooks as Git submodules. Requires just an extra two commands the first time you clone the repo, makes for a cleaner repository.
• 8.
  Mathoid + Vagrantcontinued  All configuration done in the Vagrantfile: https://github.com/cbumgard/mathoid- vagrant/blob/master/Vagrantfile  Non-provisioning changes to Vagrantfile, such as networking configuration, will take effect on a “vagrant reload” (halt + up).  Provisioning changes will not run unless you destroy and re-up, or do a “vagrant provision”.  This Vagrantfile is a combination of shell, file, and chef provisioning.
• 9.
  Vagrant: Things toNote  Pick your base box carefully.  Ideally has the configuration manager (e.g. Chef) installed that you will use for provisioning.  Avoid anything else if possible. For example a base box with Node.js built in will be trickier to upgrade to a new version than if you add Node.js as a Chef cookbook.  You can always see installed boxes via “vagrant box list”  When creating a Vagrantfile test incrementally via “vagrant provision”  Vagrant commands you should learn:  init, up, ssh, suspend, resume, halt, destroy  reload: halt + up
• 10.
  Vagrant: continued  Whenswitching networks on the host (e.g. changing WIFI networks on your laptop) you may need to “vagrant reload” for the guest VM networking.  If you want to access files from your host machine inside the guest vm, be sure to use NFS:true in your synchronized folder setup.  Gives ~10x performance accessing files. Noticeable if running a webserver like Node.js in the VM on files on your host.  Requires nfs-common installed.  Requires password on “vagrant up”. Fix for that at: https://gist.github.com/GUI/2864683
• 11.
  Vagrant: continued  Whenshell provisioning keep in mind:  Your script is running as root. No need for sudo.  Interactive prompts will hang and timeout. Make sure to add flags like “-y” to command-line calls like “apt-get”.  You can enable a GUI from the Vagrantfile if you want to do graphical work in the VM  Provisioning usually requires download files from many sources: occasionally there will be intermitent problems downloading from certain sources.  Check out Vagrant Shares. New in 1.5. Allows giving others outside your local network access to your running machine.
• 12.
  Node.js: Lessons Learned Node.js runs all Javascript code on a single thread.  So you can’t do heavy operations in the JS layer.  Consider message queues or pub/sub like Redis.io  Thinking asynchronously takes getting used to. Learn libraries like async at the start: https://github.com/caolan/async.  Flow control is very important.  Also greatly helps exception handling.  Control your versioning carefully for dependencies.  Follow semantic versioning: http://semver.org/.  If your versioning isn’t specific enough a deployment can break.  Often best to package dependencies during deployment.
• 13.
  Node.js: Lessons Continued Amazing ecosystem: always check for an existing npm module before writing something new.  I strongly recommend Grunt for building your project, and Bower for client-side web package management.  http://gruntjs.com/  http://bower.io/  Yeoman generators are a great way to bootstrap a project: http://yeoman.io/  Daemonize your app with tools like forever: https://github.com/nodejitsu/forever
• 14.
  Node.js: Lessons Continued Use clustering module: will run a copy of your Node process on each available core.  Think stateless: in general for web apps, and especially here so you can scale out.  Follow CommonJS module for code organization: http://www.commonjs.org/specs/modules/1.0/  Don’t expect to share a lot of code between the browser and the server. However the lack of context switching (all JS all the time) is the real benefit.
• 15.
  Thanks!  Chris Bumgardner https://github.com/cbumgard  https://www.linkedin.com/in/chrisbumgardner  Please don’t hesitate to contact me 
• 16.
  Links  http://www.slideshare.net/chrisbumgardner/benetech-nodejsvagrant  https://github.com/cbumgard/mathoid-vagrant http://www.vagrantup.com/downloads.html  https://www.virtualbox.org/wiki/Downloads  https://github.com/mitchellh/vagrant-aws  https://github.com/10thmagnitude/vagrant-azure  https://gist.github.com/GUI/2864683  https://github.com/caolan/async  http://semver.org/