Merge branch 'chatops-deploy-command' into 'master'

Add deploy chat command

This adds a new ChatOps command:
```
/trigger deploy <environment> to <environment>
```

See merge request !7619

4 files changed, 72 insertions, 13 deletions

diff --git a/lib/gitlab/chat_commands/command.rb b/lib/gitlab/chat_commands/command.rb
index 5f131703d40..0ec358debc7 100644
--- a/lib/gitlab/chat_commands/command.rb
+++ b/lib/gitlab/chat_commands/command.rb
@@ -4,6 +4,7 @@ module Gitlab
       COMMANDS = [
         Gitlab::ChatCommands::IssueShow,
         Gitlab::ChatCommands::IssueCreate,
+        Gitlab::ChatCommands::Deploy,
       ].freeze
 
       def execute
diff --git a/lib/gitlab/chat_commands/deploy.rb b/lib/gitlab/chat_commands/deploy.rb
new file mode 100644
index 00000000000..c0b93cca68c
--- /dev/null
+++ b/lib/gitlab/chat_commands/deploy.rb
@@ -0,0 +1,44 @@
+module Gitlab
+  module ChatCommands
+    class Deploy < BaseCommand
+      def self.match(text)
+        /\Adeploy\s+(?<from>.*)\s+to+\s+(?<to>.*)\z/.match(text)
+      end
+
+      def self.help_message
+        'deploy <environment> to <target-environment>'
+      end
+
+      def self.available?(project)
+        project.builds_enabled?
+      end
+
+      def self.allowed?(project, user)
+        can?(user, :create_deployment, project)
+      end
+
+      def execute(match)
+        from = match[:from]
+        to = match[:to]
+
+        actions = find_actions(from, to)
+        return unless actions.present?
+
+        if actions.one?
+          actions.first.play(current_user)
+        else
+          Result.new(:error, 'Too many actions defined')
+        end
+      end
+
+      private
+
+      def find_actions(from, to)
+        environment = project.environments.find_by(name: from)
+        return unless environment
+
+        environment.actions_for(to).select(&:starts_environment?)
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/result.rb b/lib/gitlab/chat_commands/result.rb
new file mode 100644
index 00000000000..324d7ef43a3
--- /dev/null
+++ b/lib/gitlab/chat_commands/result.rb
@@ -0,0 +1,5 @@
+module Gitlab
+  module ChatCommands
+    Result = Struct.new(:type, :message)
+  end
+end
diff --git a/lib/mattermost/presenter.rb b/lib/mattermost/presenter.rb
index bfbb089eb02..6b12081575d 100644
--- a/lib/mattermost/presenter.rb
+++ b/lib/mattermost/presenter.rb
@@ -24,20 +24,22 @@ module Mattermost
         end
       end
 
-      def present(resource)
-        return not_found unless resource
-
-        if resource.respond_to?(:count)
-          if resource.count > 1
-            return multiple_resources(resource)
-          elsif resource.count == 0
-            return not_found
+      def present(subject)
+        return not_found unless subject
+
+        if subject.is_a?(Gitlab::ChatCommands::Result)
+          show_result(subject)
+        elsif subject.respond_to?(:count)
+          if subject.many?
+            multiple_resources(subject)
+          elsif subject.none?
+            not_found
           else
-            resource = resource.first
+            single_resource(subject)
           end
+        else
+          single_resource(subject)
         end
-
-        single_resource(resource)
       end
 
       def access_denied
@@ -46,6 +48,10 @@ module Mattermost
 
       private
 
+      def show_result(result)
+        ephemeral_response(result.message)
+      end
+
       def not_found
         ephemeral_response("404 not found! GitLab couldn't find what you were looking for! :boom:")
       end
@@ -54,7 +60,7 @@ module Mattermost
         return error(resource) if resource.errors.any? || !resource.persisted?
 
         message = "### #{title(resource)}"
-        message << "\n\n#{resource.description}" if resource.description
+        message << "\n\n#{resource.description}" if resource.try(:description)
 
         in_channel_response(message)
       end
@@ -74,7 +80,10 @@ module Mattermost
       end
 
       def title(resource)
-        "[#{resource.to_reference} #{resource.title}](#{url(resource)})"
+        reference = resource.try(:to_reference) || resource.try(:id)
+        title = resource.try(:title) || resource.try(:name)
+
+        "[#{reference} #{title}](#{url(resource)})"
       end
 
       def header_with_list(header, items)