CLOUD-2078-Uninstall Docker on Linux (#328)

Author: MarkW

README.md

@@ -196,6 +196,14 @@ class { 'docker':
 }
 ```
 
+To uninstall docker, add the following to the manifest file:
+
+```puppet
+class { 'docker':
+  ensure => absent
+}
+```
+
 Only Docker EE is supported on Windows. To install docker on Windows 2016 and above the `docker_ee` parameter must be specified: 
 ```puppet
 class { 'docker':

manifests/init.pp

@@ -632,14 +632,20 @@
     $root_dir_flag = '--data-root'
   }
 
-  contain 'docker::repos'
-  contain 'docker::install'
-  contain 'docker::config'
-  contain 'docker::service'
+  if $ensure != 'absent' {
+    contain 'docker::repos'
+    contain 'docker::install'
+    contain 'docker::config'
+    contain 'docker::service'
 
-  Class['docker::repos'] -> Class['docker::install'] -> Class['docker::config'] -> Class['docker::service']
-  Class['docker'] -> Docker::Registry <||> -> Docker::Image <||>
-  Class['docker'] -> Docker::Image <||>
-  Class['docker'] -> Docker::Run <||>
+    Class['docker::repos'] -> Class['docker::install'] -> Class['docker::config'] -> Class['docker::service']
+    Class['docker'] -> Docker::Registry <||> -> Docker::Image <||>
+    Class['docker'] -> Docker::Image <||>
+    Class['docker'] -> Docker::Run <||>
+  } else {
+    contain 'docker::repos'
+    contain 'docker::install'
 
+    Class['docker::repos'] -> Class['docker::install']
+  }
 }

spec/acceptance/docker_full_spec.rb

@@ -227,6 +227,23 @@ class { 'docker':
           end
         end
       end
+
+
+      context 'uninstall docker' do
+        before(:each) do
+          @pp =<<-EOS
+            class {'docker':
+              ensure => 'absent'
+            }
+          EOS
+          apply_manifest(@pp, :catch_failures => true)
+          sleep 4
+        end
+
+        it 'should uninstall successfully' do
+        shell('docker ps', :acceptable_exit_codes => [1, 127])
+        end
+      end
     end
 
     describe 'docker::image' do