Move RunnerConnection into class Runner

The old approach was to require the runner connection. This did
not work anymore with Zeitwerk in Rails 6. @sebastian.serth and I
moved the Connection class in `lib` into the ActiveRecord class
`Runner`. This will also work with future changes like specific
error classes. Furthermore the config was fixed and simplified.

Co-authored-by: Sebastian Serth <Sebastian.Serth@hpi.de>

app/models/runner.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require 'runner/runner_connection'
-
 class Runner < ApplicationRecord
   BASE_URL = CodeOcean::Config.new(:code_ocean).read[:runner_management][:url]
   HEADERS = {'Content-Type' => 'application/json'}.freeze
@@ -18,7 +16,7 @@ class Runner < ApplicationRecord
 
   def self.for(user, exercise)
     execution_environment = ExecutionEnvironment.find(exercise.execution_environment_id)
-    runner = Runner.find_or_create_by(user: user, execution_environment: execution_environment)
+    runner = find_or_create_by(user: user, execution_environment: execution_environment)
 
     return runner if runner.save
 
@@ -51,7 +49,7 @@ class Runner < ApplicationRecord
     starting_time = Time.zone.now
     websocket_url = execute_command(command)[:websocketUrl]
     EventMachine.run do
-      socket = RunnerConnection.new(websocket_url)
+      socket = Runner::Connection.new(websocket_url)
       yield(self, socket) if block_given?
     end
     Time.zone.now - starting_time # execution time
@@ -70,7 +68,7 @@ class Runner < ApplicationRecord
 
   def new_runner
     url = "#{BASE_URL}/runners"
-    time_limit = CodeOcean::Config.new(:code_ocean)[:runner_management][:unused_runner_expiration_time]
+    time_limit = CodeOcean::Config.new(:code_ocean).read[:runner_management][:unused_runner_expiration_time]
     body = {executionEnvironmentId: execution_environment.id, timeLimit: time_limit}
     response = Faraday.post(url, body.to_json, HEADERS)
     response_body = parse response

config/code_ocean.yml.ci

@@ -11,5 +11,4 @@ test:
     enabled: false
   runner_management:
     url: https://runners.example.org
-    cleanup_interval: 60
     unused_runner_expiration_time: 180

config/code_ocean.yml.example

@@ -4,27 +4,25 @@ default: &default
     answers_per_query: 3
   code_pilot:
     enabled: false
+    url: //localhost:3000
   codeharbor:
     enabled: false
   codeocean_events:
     enabled: false
+  prometheus_exporter:
+    enabled: false
   runner_management:
     url: https://runners.example.org
-    cleanup_interval: 60
     unused_runner_expiration_time: 180
 
 development:
+  <<: *default
   flowr:
     enabled: true
     answers_per_query: 3
-  code_pilot:
-    enabled: false
-    url: //localhost:3000
   codeharbor:
     enabled: true
     url: https://codeharbor.openhpi.de
-  prometheus_exporter:
-    enabled: false
 
 production:
   <<: *default
@@ -33,5 +31,3 @@ production:
 
 test:
   <<: *default
-  prometheus_exporter:
-    enabled: false

lib/runner/connection.rb

@@ -3,7 +3,7 @@
 require 'faye/websocket/client'
 require 'json_schemer'
 
-class RunnerConnection
+class Runner::Connection
   EVENTS = %i[start output exit stdout stderr].freeze
   BACKEND_OUTPUT_SCHEMA = JSONSchemer.schema(JSON.parse(File.read('lib/runner/backend-output.schema.json')))