Basic "healthcheck" endpoint

app/controllers/health_check_controller.rb

@@ -0,0 +1,16 @@
+class HealthCheckController < ActionController::Base # :nodoc:
+  rescue_from(Exception) { render_down }
+
+  def show
+    render_up
+  end
+
+  private
+  def render_up
+    render plain: 'up', status: 200
+  end
+
+  def render_down
+    render plain: 'down', status: 503
+  end
+end

config/routes.rb

@@ -171,6 +171,8 @@
   get 'bioschemas/test' => 'bioschemas#test'
   post 'bioschemas/test' => 'bioschemas#run_test'
 
+  get 'up' => 'health_check#show'
+
   # The priority is based upon order of creation: first created -> highest priority.
   # See how all your routes lay out with "rake routes".
 

docker-compose-prod.yml

@@ -8,6 +8,10 @@ services:
       target: production
     image: ${PREFIX}-app
     restart: always
+    healthcheck:
+      test: curl -f http://localhost:3000/up
+      interval: 5s
+      timeout: 300s
     env_file: .env
     depends_on:
       - db