Allow live events to use vault for credentials

Change-Id: I6116261bec529b8e144408d9606f94ccfe8db833
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/254098
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Ethan Vizitei <evizitei@instructure.com>
QA-Review: Jacob Burroughs <jburroughs@instructure.com>
Product-Review: Jacob Burroughs <jburroughs@instructure.com>

config/initializers/live_events.rb

@@ -44,5 +44,12 @@ Rails.configuration.to_prepare do
       plugin_settings
     end
   }
+  LiveEvents.aws_credentials = -> (settings) {
+    if settings['vault_credential_path']
+      Canvas::Vault::AwsCredentialProvider.new(settings['vault_credential_path'])
+    else
+      nil
+    end
+  }
   LiveEvents.stream_client = StubbedClient if ENV['STUB_LIVE_EVENTS_KINESIS']
 end

gems/live_events/lib/live_events.rb

@@ -34,6 +34,14 @@ module LiveEvents
       @settings.call
     end
 
+    def aws_credentials=(aws_credentials)
+      @aws_credentials = aws_credentials
+    end
+
+    def aws_credentials(config)
+      @aws_credentials.call(config)
+    end
+
     def max_queue_size=(size)
       @max_queue_size = size
     end

gems/live_events/lib/live_events/client.rb

@@ -57,6 +57,10 @@ module LiveEvents
         aws[:secret_access_key] = plugin_config['aws_secret_access_key_dec']
       end
 
+      if plugin_config['custom_aws_credentials']
+        aws[:credentials] = LiveEvents.aws_credentials(plugin_config)
+      end
+
       aws[:region] = plugin_config['aws_region'].presence || 'us-east-1'
 
       if plugin_config['aws_endpoint'].present?

gems/live_events/spec/live_events/client_spec.rb

@@ -84,6 +84,20 @@ describe LiveEvents::Client do
       expect(res[:endpoint]).to eq("http://example.com:6543/")
       LiveEvents.worker.stop!
     end
+
+    it "should load custom creds" do
+      LiveEvents.aws_credentials = -> (settings) {
+        settings['value_to_return']
+      }
+
+      res = LiveEvents::Client.aws_config({
+        'custom_aws_credentials' => 'true',
+        'value_to_return' => 'a_value'
+      })
+
+      expect(res[:credentials]).to eq('a_value')
+      LiveEvents.worker.stop!
+    end
   end
 
   describe "post_event" do