Pin sinatra gem

Sinatra 2.0.0 was released on the 7th of May 2017.  It requires rack ~>
2.0 and *that* requires ruby 2.2.  Puppet 4 AIO ships with ruby 2.1, so
pin sinatra to prevent errors like.

```
Error: Execution of '/opt/puppetlabs/puppet/bin/gem install --no-rdoc
--no-ri sinatra' returned 1: ERROR:  Error installing sinatra:
        rack requires Ruby version >= 2.2.2.
```

Fixes #140

README.md

@@ -484,6 +484,11 @@ class { '::r10k::webhook':
 }
 ```
 
+### Webhook sinatra gem installation
+
+By default, the `r10k::webhook::package` class uses the `puppet_gem` provider to install the latest ruby 2.1 compatible version of sinatra ('~> 1.0').
+If you are overriding `r10k::webhook::package::provider`, you will also need to override `r10k::webhook::package::sinatra_version`.
+
 ### Webhook Slack notifications
 
 You can enable Slack notifications for the webhook. You will need a

manifests/params.pp

@@ -148,6 +148,7 @@
   $webhook_configfile_mode       = '0644'
   $webhook_ignore_environments   = []
   $webhook_mco_arguments         = undef
+  $webhook_sinatra_version       = '~> 1.0'      # Sinatra 2 requires rack 2 which in turn requires ruby 2.2. Puppet 4 AIO ships with ruby 2.1
 
   # Service Settings for SystemD in EL7
   if $::osfamily == 'RedHat' and $::operatingsystemmajrelease == '7' {

manifests/webhook/package.pp

@@ -1,12 +1,13 @@
 # Private class, do not include it directly.
 # Installs the webhook packages
 class r10k::webhook::package (
-  $is_pe_server = $r10k::params::is_pe_server,
-  $provider     = $r10k::params::provider,
+  $is_pe_server    = $r10k::params::is_pe_server,
+  $provider        = $r10k::params::provider,
+  $sinatra_version = $r10k::params::webhook_sinatra_version,
 ) inherits r10k::params {
   if !defined(Package['sinatra']) {
     package { 'sinatra':
-      ensure   => installed,
+      ensure   => $sinatra_version,
       provider => $provider,
       before   => Service['webhook'],
     }

spec/classes/webhook/package_spec.rb

@@ -20,7 +20,7 @@
 
         it do
           is_expected.to contain_package('sinatra').with(
-            ensure:   'installed',
+            ensure:   '~> 1.0',
             provider: 'puppet_gem'
           )
         end
@@ -36,7 +36,7 @@
           )
         end
 
-        it { is_expected.to contain_package('sinatra').with(ensure: 'installed') }
+        it { is_expected.to contain_package('sinatra').with(ensure: '~> 1.0') }
         it { is_expected.to contain_package('webrick').with(ensure: 'installed') }
         it { is_expected.to contain_package('json').with(ensure: 'installed') }
       end

spec/classes/webhook_spec.rb

@@ -18,12 +18,7 @@
           )
         end
 
-        it do
-          is_expected.to contain_package('sinatra').with(
-            ensure:   'installed',
-            provider: 'puppet_gem'
-          )
-        end
+        it { is_expected.to contain_class('r10k::webhook::package') }
         it { is_expected.not_to contain_file('peadmin-cert.pem').with(path: '/var/lib/peadmin/.mcollective.d/peadmin-cert.pem') }
       end
     end