Refactor sync_environment methods

* Add delete_environment method
* Change return value to allow raising an exception

app/controllers/execution_environments_controller.rb

@@ -177,6 +177,8 @@ class ExecutionEnvironmentsController < ApplicationController
 
     success = ExecutionEnvironment.all.map do |execution_environment|
       Runner.strategy_class.sync_environment(execution_environment)
+    rescue Runner::Error
+      false
     end
     if success.all?
       redirect_to ExecutionEnvironment, notice: t('execution_environments.index.synchronize_all.success')

app/models/execution_environment.rb

@@ -33,10 +33,11 @@ class ExecutionEnvironment < ApplicationRecord
   before_validation :clean_exposed_ports
   validates :exposed_ports, array: {numericality: {greater_than_or_equal_to: 0, less_than: 65_536, only_integer: true}}
 
-  def set_default_values
-    set_default_values_if_present(permitted_execution_time: 60, pool_size: 0)
-  end
-  private :set_default_values
+  after_destroy :delete_runner_environment
+  after_save :working_docker_image?, if: :validate_docker_image?
+
+  after_rollback :delete_runner_environment, on: :create
+  after_rollback :sync_runner_environment, on: %i[update destroy]
 
   def to_s
     name
@@ -86,5 +87,23 @@ class ExecutionEnvironment < ApplicationRecord
   rescue Runner::Error => e
     errors.add(:docker_image, "error: #{e}")
   end
-  private :working_docker_image?
+
+  def delete_runner_environment
+    Runner.strategy_class.remove_environment(self)
+  rescue Runner::Error => e
+    unless errors.include?(:docker_image)
+      errors.add(:docker_image, "error: #{e}")
+      raise ActiveRecord::RecordInvalid.new(self)
+    end
+  end
+
+  def sync_runner_environment
+    previous_saved_environment = self.class.find(id)
+    Runner.strategy_class.sync_environment(previous_saved_environment)
+  rescue Runner::Error => e
+    unless errors.include?(:docker_image)
+      errors.add(:docker_image, "error: #{e}")
+      raise ActiveRecord::RecordInvalid.new(self)
+    end
+  end
 end

app/models/runner.rb

@@ -140,16 +140,20 @@ class Runner < ApplicationRecord
     rescue Runner::Error::EnvironmentNotFound
       # Whenever the environment could not be found by the runner management, we
       # try to synchronize it and then forward a more specific error to our callee.
-      if strategy_class.sync_environment(execution_environment)
+      begin
+        strategy_class.sync_environment(execution_environment)
+      rescue Runner::Error
+        # An additional error was raised during synchronization
+        raise Runner::Error::EnvironmentNotFound.new(
+          "The execution environment with id #{execution_environment.id} was not found by the runner management. "\
+          'In addition, it could not be synced so that this probably indicates a permanent error.'
+        )
+      else
+        # No error was raised during synchronization
         raise Runner::Error::EnvironmentNotFound.new(
           "The execution environment with id #{execution_environment.id} was not found yet by the runner management. "\
           'It has been successfully synced now so that the next request should be successful.'
         )
-      else
-        raise Runner::Error::EnvironmentNotFound.new(
-          "The execution environment with id #{execution_environment.id} was not found by the runner management."\
-          'In addition, it could not be synced so that this probably indicates a permanent error.'
-        )
       end
     end
   end