GOV.UK Puppet

This repository contains the puppet modules and manifests for GOV.UK.

Getting started

In order to run/test the Puppet manifests you will need Ruby 1.9.x and Bundler.

Dependencies are managed with Bundler and librarian-puppet, but hopefully this should be transparent unless you need to update the dependencies yourself.

If you're on a GOV.UK development VM, you should be able to run

$ govuk_puppet

which is a thin wrapper around the puppet-apply-dev script.

Standards

Please familiarise yourself with our Puppet style guide before contributing to this repository.

Pay particular attention to the section 'Things that should not be in the Puppet Repo'.

Dependencies

All modules from librarian-puppet are cached in this repo under vendor/puppet/ in order to ensure that third-party code doesn't change underneath us, protect us from downtime, and improve build times.

Installing

If you're using this repo for the first time or the contents of Gemfile[.lock] or Puppetfile[.lock] have recently changed then you'll need to run:

$ bundle install
$ bundle exec rake librarian:install

Please avoid using librarian-puppet directly because it's not very good at respecting or maintaining its own config file.

Running these commands will often be the solution to Puppet errors about unknown classes or functions such as:

Unknown function validate_bool at …
Could not find class apt for …
Puppet::Parser::AST::Resource failed with error ArgumentError: Invalid resource type apt::source …

This should also fix errors while trying to run govuk_puppet, of the form:

chown: changing ownership of '/home/vagrant/.puppet/[…]': Operation not permitted

Updating

If you need to add a new module to the Puppetfile then you will need to run the following to install it and update the cache:

$ bundle exec rake librarian:package

If you need to update an existing module to a newer version, you'll need to run the following:

$ bundle exec rake 'librarian:update[alphagov/tune_ext]'

Afterwards you should commit the Puppetfile, Puppetfile.lock and any new files in vendor/puppet/. If updating a module then you will need to manually delete the old tarball from the cache directory.

NB: There should never be any changes to .librarian/puppet/config.

Testing

Assuming that your dependencies are installed, run all the tests:

$ bundle exec rake

The module tests are located in modules/<module>/spec. See the RSpec Puppet documentation for more details. The specs are run in parallel by default.

Puppet-lint is a tool that checks various syntax and style rules common to well written Puppet code. It can be run with:

$ bundle exec rake lint

This outputs a set of errors or warnings that should be fixed. See the Puppet Style Guide for more information.

Scoped testing

You can run the tests for a specific module or modules by setting an environment variable, mods for the rake task, e.g.

$ bundle exec rake mods=nginx,varnish

The manifests/ directory is considered one module called manifests for this purpose.

$ bundle exec rake mods=manifests,govuk

Node testing

Some issues that span multiple classes or modules may not be picked up unit testing. Duplicate resources and mislabelled dependencies are such examples. To catch these, all available govuk::node classes can be exercised with:

$ bundle exec rake spec:nodes

Compiling node complete node catalogs takes quite a long time, so you may wish to restrict it to certain classes of node by setting the environment variable classes for the rake task, e.g.

$ bundle exec rake spec:nodes classes=frontend,backend

Vagrant testing

Prerequisites

You will need an up-to-date checkout of the private govuk-provisioning repository for node definitions.

Setup

It is recommended that you use Vagrant > 1.4 from a binary/system install. alphagov/gds-boxen can set this up for you.

Usage

You need only bring up the subset of nodes that you're working on. For example, to bring up a frontend and backend:

vagrant up frontend-1.frontend backend-1.backend

Vagrant will run the Puppet provisioner against the node when it boots up. Nodes should look almost identical to that of our real production/staging/preview environments, including network addresses. To access a node's services like HTTP/HTTPS you can point your hosts file to the host-only IP address (eth1).

Physical attributes like memory and num_cores will be ignored because they don't scale appropriately to local VMs, but can still be customised as described below.

Customisation

Node definitions can be overridden with a nodes.local.yaml file in the vagrant-govuk directory. This is merged on top of all other node definitions. The following keys are currently available for customisation:

box_dist Ubuntu distribution. Currently "precise".
box_version Internal version number of the GDS basebox.
memory Amount of RAM. Default is "384".
ip IP address for hostonly networking. Currently all subnets are /16.
class Name of the Puppet class/role.

For example to increase the amount of RAM on a PuppetMaster:

---
puppetmaster-1.management:
  memory: 768

Errors

Some errors that you might encounter..

NFS failed mounts

[frontend-1.frontend] Mounting NFS shared folders...
Mounting NFS shared folders failed. This is most often caused by the NFS
client software not being installed on the guest machine. Please verify
that the NFS client software is properly installed, and consult any resources
specific to the linux distro you're using for more information on how to do this.

This seems to be caused by a combination of OSX, VirtualBox, and Cisco AnyConnect. Try temporarily disconnecting from the VPN when bringing up a new node. You can also set VAGRANT_GOVUK_NFS=no as an environment variable to disable the use of NFS. This is less performant but fine for checking puppet runs.

tahb/govuk-puppet