adding Docker services

Author: scott coulton

README.md

@@ -499,6 +499,53 @@ docker::swarm {'cluster_worker':
 ensure => absent
 }
 ```
+### Docker services
+Docker services allow to create distributed applications across multiple swarm nodes. A service is a set of containers that are replicated across your swarm.
+To configure a service with Puppet code please see the following examples
+
+To create a service
+```puppet
+docker::services {'redis':
+    create => true,   
+    service_name => 'redis',
+    image => 'redis:latest',
+    publish => '6379:639',
+    replicas => '5', 
+    extra_params => ['--update-delay 1m', '--restart-window 30s']
+  }
+```
+In this example we are creating a service called `redis`, as it is a new service we have set `create => true`. The `service_name` resource is the name which Docker knows the service as. The `image` resource is the image you want to base the service off, `publish` is the ports that want exposed to the outside world for the service to be consumed, `replicas` sets the amount of tasks (containers) that you want running in the service, `extra_params` allows you to configure any of the other flags that Docker gives you when you create a service for more info see `docker service create --help`
+
+To update the service
+```puppet 
+docker::services {'redis_update':
+  create => false,
+  update => true,
+  service_name => 'redis',
+  replicas => '3',
+}
+
+In this example we have taken the service that we created earlier `redis` set the `create => false` and this time added `update => true`. We then decleared the service name `redis` we have then updated the servce to have only 3 replicas, not 5. The `extra_params` resource is also available in the update class.
+
+To scale a service
+```puppet
+docker::services {'redis_scale':
+  create => false,
+  scale => true,
+  service_name => 'redis',
+  replicas => '10', 
+}
+```
+In this example we have used the command `docker service scale` with Puppet code. We have taken our service `redis` set the `create => false` and `scale => true` When using scale you have to declare your `service_name` then the number of replicas that you want. In this example we are going to scale to `10`
+
+To remove a service
+```puppet
+docker::services {'redis':
+  ensure => 'absent',
+  service_name => 'redis',
+}
+```
+To remove a a service from your swarm just set `ensure => absent` and the service_name of your service.
 
 ### Private registries
 By default images will be pushed and pulled from [index.docker.io](https://index.docker.io) unless you've specified a server. If you have your own private registry without authentication, you can fully qualify your image name. If your private registry requires authentication you may configure a registry:

Rakefile

@@ -22,7 +22,6 @@ end
 
 PuppetLint.configuration.relative = true
 PuppetLint.configuration.disable_80chars
-PuppetLint.configuration.log_format = "%{path}:%{linenumber}:%{check}:%{KIND}:%{message}"
 PuppetLint.configuration.fail_on_warnings = true
 
 # Forsake support for Puppet 2.6.2 for the benefit of cleaner code.

lib/puppet/parser/functions/docker_service_flags.rb

@@ -0,0 +1,56 @@
+require 'shellwords'
+
+module Puppet::Parser::Functions
+  # Transforms a hash into a string of docker swarm init flags
+  newfunction(:docker_service_flags, :type => :rvalue) do |args|
+    opts = args[0] || {}
+    flags = []
+
+    if opts['detach'].to_s != 'true'
+      flags << '--detach'
+    end
+    
+    if opts['service_name'].to_s != 'undef'
+      flags << "'#{opts['service_name']}'"	    
+    end
+
+    if opts['env'].to_s != 'undef'
+      flags << "--env '#{opts['env']}'"
+    end
+    
+    if opts['label'].to_s != 'undef'
+      flags << "--label '#{opts['label']}'"
+    end
+
+    if opts['publish'].to_s != 'undef'
+      flags << "--publish '#{opts['publish']}'"
+    end
+    
+    if opts['replicas'].to_s != 'undef'
+      flags << "--replicas '#{opts['replicas']}'"
+    end      
+
+    if opts['tty'].to_s != 'false'
+      flags << '--tty'
+    end   
+    
+    if opts['user'].to_s != 'undef'
+      flags << "--user '#{opts['publish']}'"
+    end   
+    
+    if opts['workdir'].to_s != 'undef'
+      flags << "--workdir '#{opts['workdir']}'"
+    end  
+    
+    if opts['extra_params'].each do |param|
+      flags << param
+     end
+    end
+   
+    if opts['image'].to_s != 'undef'
+      flags << "'#{opts['image']}'"      
+    end
+
+    flags.flatten.join(" ")
+  end
+end

lib/puppet/parser/functions/docker_swarm_init_flags.rb

@@ -45,7 +45,7 @@ module Puppet::Parser::Functions
     if opts['snapshot_interval'].to_s != 'undef'
       flags << "--snapshot-interval '#{opts['snapshot_interval']}'"
     end 
-
+    
     flags.flatten.join(" ")
   end
 end

manifests/service.pp

@@ -148,7 +148,7 @@
   case $service_provider {
     'systemd': {
       file { '/etc/systemd/system/docker.service.d':
-        ensure => directory
+        ensure => directory,
       }
 
       if $service_overrides_template {

manifests/services.pp

@@ -0,0 +1,186 @@
+# == Define: docker::services
+# 
+# A define that managers a Docker services 
+#
+# == Paramaters
+#
+# [*ensure*] 
+#  This ensures that the service is present or not.
+#  Defaults to present
+#
+# [*image*] 
+#  The Docker image to spwan the service from. 
+#  Defualts to undef  
+#
+# [*detach*] 
+#  Exit immediately instead of waiting for the service to converge (default true)
+#  Defaults to true
+#
+# [*env*]
+#  Set environment variables
+#  Defaults to undef
+#
+# [*label*]
+#  Service labels.
+#  This used as metdata to configure constraints etc.
+#  Defaults to undef
+#
+# [*publish*]
+#  Publish a port as a node port.
+#  Defaults to undef
+#
+# [*replicas*]
+#  Number of tasks (containers per service) 
+#  defaults to undef
+#  
+# [*tty*]
+#  Allocate a pseudo-TTY
+#  Defaults to false
+#
+# [*user*]
+#  Username or UID (format: <name|uid>[:<group|gid>])
+#  Defaults to undef
+#
+# [*workdir*]
+#  Working directory inside the container
+#  Defaults to false
+#
+# [*extra_params*]
+#  Allows you to pass any other flag that the Docker service create supports.
+#  This must be passed as an array. See docker service create --help for all options
+#  defaults to []
+#
+# [*update*]
+#  This changes the docker command to 
+#  docker service update, you must pass a service name with this option 
+#
+# [*scale*]
+#  This changes the docker command to
+#  docker service scale, this can only be used with service name and 
+#  replicas
+#  
+
+define docker::services(
+
+  $ensure = 'present',
+  $image = undef,
+  $detach = true,
+  $env = undef,
+  $service_name = undef,
+  $label = undef,
+  $publish = undef,
+  $replicas = undef,
+  $tty = false,
+  $user = undef,
+  $workdir = undef,
+  $extra_params = [],
+  $create = true,
+  $update = false,
+  $scale = false,
+  ){
+
+  include docker::params
+
+  $docker_command = "${docker::params::docker_command} service"
+  validate_re($ensure, '^(present|absent)$')
+  validate_string($docker_command)
+  validate_string($image)
+  validate_string($env)
+  validate_string($service_name)
+  validate_string($label)
+  validate_string($publish)
+  validate_string($replicas)
+  validate_string($user)
+  validate_string($workdir)
+  validate_bool($detach)
+  validate_bool($tty)
+  validate_bool($create)
+  validate_bool($update)
+  validate_bool($scale)
+
+  if $ensure == 'absent' {
+    if $update {
+      fail('When removing a service you can not update it.')
+    }
+    if $scale {
+      fail('When removing a service you can not update it.')
+    }
+  }
+
+  if $create {
+  $docker_service_create_flags = docker_service_flags({
+    detach => $detach,
+    env => $env,
+    service_name => $service_name,
+    label => $label,
+    publish => $publish,
+    replicas => $replicas,
+    tty => $tty,
+    user => $user,
+    workdir => $workdir,
+    extra_params => any2array($extra_params),
+    image => $image,
+    })
+
+  $exec_create = "${docker_command} create --name ${docker_service_create_flags}"
+  $unless_create = "docker service ls | grep -w ${service_name}"
+
+  exec { 'Docker service create':
+    command     => $exec_create,
+    environment => 'HOME=/root',
+    path        => ['/bin', '/usr/bin'],
+    timeout     => 0,
+    unless      => $unless_create,
+    }
+  }
+
+  if $update {
+  $docker_service_flags = docker_service_flags({
+    detach => $detach,
+    env => $env,
+    service_name => $service_name,
+    label => $label,
+    publish => $publish,
+    replicas => $replicas,
+    tty => $tty,
+    user => $user,
+    workdir => $workdir,
+    extra_params => any2array($extra_params),
+    image => $image,
+    })
+
+  $exec_update = "${docker_command} update ${docker_service_flags}"
+
+  exec { 'Docker service update':
+    command     => $exec_update,
+    environment => 'HOME=/root',
+    path        => ['/bin', '/usr/bin'],
+    timeout     => 0,
+    }
+  }
+
+  if $scale {
+  $docker_service_flags = docker_service_flags({
+    service_name => $service_name,
+    replicas => $replicas,
+    extra_params => any2array($extra_params),
+    })
+
+  $exec_scale = "${docker_command} scale ${docker_service_flags}"
+
+  exec { 'Docker service scale':
+    command     => $exec_scale,
+    environment => 'HOME=/root',
+    path        => ['/bin', '/usr/bin'],
+    timeout     => 0,
+    }
+  }
+
+  if $ensure == 'absent' {
+    exec { 'Remove service':
+      command => "docker service rm ${service_name}",
+      onlyif  => "docker service ls | grep -w ${service_name}",
+      path    => ['/bin', '/usr/bin'],
+    }
+  }
+}

spec/defines/services_spec.rb

@@ -0,0 +1,57 @@
+require 'spec_helper'
+
+describe 'docker::services', :type => :define do
+  let(:title) { 'create services' }
+	let(:facts) { {
+		:osfamily                  => 'Debian',
+		:operatingsystem           => 'Debian',
+		:lsbdistid                 => 'Debian',
+		:lsbdistcodename           => 'jessie',
+		:kernelrelease             => '3.2.0-4-amd64',
+		:operatingsystemmajrelease => '8',
+	} }
+
+  context 'with ensure => present and service create' do
+    let(:params) { {
+	    'create'       => true,
+	    'service_name' => 'foo',
+            'image'        => 'foo:bar',
+	    'publish'      => '80:80',
+            'replicas'     => '5',
+            'extra_params' => ['--update-delay 1m', '--restart-window 30s']	    
+    } }
+    it { is_expected.to compile.with_all_deps }
+    it { should contain_exec('Docker service create').with_command(/docker service create/) }
+  end
+
+  context 'with ensure => present and service update' do
+    let(:params) { {
+	    'create'         => false,
+	    'update'         => true,
+            'service_name'   => 'foo',
+	    'image'          => 'bar:latest',
+    } }
+    it { is_expected.to compile.with_all_deps }
+    it { should contain_exec('Docker service update').with_command(/docker service update/) }
+  end
+ 
+  context 'with ensure => present and service scale' do
+    let(:params) { {
+	    'create'         => false,
+	    'scale'          => true,
+            'service_name'   => 'bar',
+	    'replicas'       => '5',
+    } }
+    it { is_expected.to compile.with_all_deps }
+    it { should contain_exec('Docker service scale').with_command(/docker service scale/) }
+  end
+ 
+  context 'with ensure => absent' do
+    let(:params) { {
+	    'ensure'         => 'absent',
+	    'service_name'   => 'foo',
+    } }
+    it { is_expected.to compile.with_all_deps }
+    it { should contain_exec('Remove service').with_command(/docker service rm/) }
+  end
+end