Error system and error handling of AssignmentService

app/controllers/foreman_ansible_director/api/v2/ansible_director_api_controller.rb

@@ -5,6 +5,19 @@ module Api
     module V2
       class AnsibleDirectorApiController < ::Api::V2::BaseController
         include ::Api::Version2
+        include ::ForemanAnsibleDirector::Errors::Helpers
+
+        rescue_from 'ForemanAnsibleDirector::Errors::ApplicationError' do |exception|
+          message = {
+            error_code: exception.error_code,
+            title: exception.title,
+            description: exception.description,
+            docs_link: exception.docs_link,
+          }.compact
+
+          render_error('custom_error', status: exception.response_status,
+                       locals: { message: message })
+        end
 
         def find_organization
           @organization = Organization.current || find_optional_organization

app/controllers/foreman_ansible_director/api/v2/assignments_controller.rb

@@ -11,7 +11,6 @@ def assignments
             target_type: params[:target],
             target_id: params[:target_id]
           )
-          # TODO: Null check target
           @assignments = target.resolved_ansible_content
         end
 

app/lib/foreman_ansible_director/errors/application_error.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module ForemanAnsibleDirector
+  module Errors
+    class ApplicationError < StandardError
+      attr_reader :error_code, :title, :description, :response_status, :docs_link
+
+      def initialize(error_code, title_args, description_args, args)
+        if args
+          title_args.merge!(args)
+          description_args.merge!(args)
+        end
+        error_object = ::ForemanAnsibleDirector::Errors.error_object(error_code, title_args, description_args)
+        @error_code = error_code
+        @response_status = error_object[:response_status]
+        @title = error_object[:title]
+        @description = error_object[:description]
+        @docs_link = error_object[:docs_link]
+        super()
+      end
+    end
+
+    def self.error_object(error_code, title_args, description_args)
+      raw = ::ForemanAnsibleDirector::Errors::ERROR_OBJECTS[error_code]
+
+      {
+        response_status: raw[:response_status],
+        title: raw[:title] % title_args,
+        description: raw[:description] % description_args,
+        docs_link: raw[:docs_link],
+      }
+    end
+
+    def self.env(message)
+      # ^ADR-(?<error_source>\d{3})-(?<source_id>\d{3})-(?<failure_source>\d{3})-(?<failure_id>\d{3})$
+
+      if Rails.env.development?
+        return message # TODO: This should return more verbose output at some point
+      end
+      message
+    end
+
+    ERROR_OBJECTS = HashWithIndifferentAccess.new({
+      "ADR-003-005-004-001": {
+        response_status: :not_found,
+        title: <<~TITLE,
+          Invalid target type %<type>s specified.
+        TITLE
+        description: <<~DESC,
+          A target type with the name %<type>s was not found. You likely misspelled it.
+          Allowed types are [HOST, HOSTGROUP, ACR, CONTENT].
+        DESC
+      },
+      "ADR-003-005-005-001": {
+        response_status: :not_found,
+        title: <<~TITLE,
+          Target not found.
+        TITLE
+        description: <<~DESC,
+          A target of type %<target_type>s with id %<target_id>s was not found.
+        DESC
+      },
+    })
+  end
+end

app/lib/foreman_ansible_director/errors/helpers.rb

@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+module ForemanAnsibleDirector
+  module Errors
+    module Helpers
+      def app_error_for(error_code, title_args: {}, description_args: {}, args: nil)
+        ::ForemanAnsibleDirector::Errors::ApplicationError.new(error_code, title_args, description_args, args)
+      end
+
+      class ErrorScope
+        def initialize(errors)
+          @errors = errors
+        end
+
+        def try(&block)
+          @try_block = block
+          execute
+        end
+
+        def execute
+          @try_block&.call
+        rescue ::ForemanAnsibleDirector::Errors::ApplicationError => e
+          # Disabling rubocop here, because the "thing" we want to do with the error is not implemented yet
+          # rubocop:disable Style/GuardClause
+          if @errors.include?(e.error_code)
+            # TODO: do something with expected error
+            raise e
+          else
+            raise ::ForemanAnsibleDirector::Errors::UnexpectedError
+          end
+          # rubocop:enable Style/GuardClause
+        rescue StandardError
+          raise ::ForemanAnsibleDirector::Errors::UnknownError
+        end
+      end
+
+      class ErrorScopeRescue
+        def initialize(errors)
+          @errors = errors
+        end
+
+        def try(&block)
+          @try_block = block
+          self
+        end
+
+        def catch(&block)
+          @catch_block = block
+          execute
+        end
+
+        def execute
+          @try_block&.call
+        rescue ::ForemanAnsibleDirector::Errors::ApplicationError => e
+          @catch_block&.call(e)
+          if @errors.include?(e.error_code)
+            # TODO: do something with expected error
+            raise e
+          end
+        rescue StandardError
+          raise ::ForemanAnsibleDirector::Errors::UnknownError
+        end
+      end
+
+      def error_scope_rescue(errors)
+        result = ErrorScopeRescue.new(errors)
+        yield(result) if block_given?
+        result
+      end
+
+      def error_scope(errors)
+        result = ErrorScope.new(errors)
+        yield(result) if block_given?
+        result
+      end
+    end
+  end
+end

app/lib/foreman_ansible_director/errors/unexpected_error.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module ForemanAnsibleDirector
+  module Errors
+    class UnexpectedError < StandardError
+      def initialize
+        super('An unexpected error has occurred.')
+      end
+    end
+  end
+end

app/lib/foreman_ansible_director/errors/unknown_error.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module ForemanAnsibleDirector
+  module Errors
+    class UnknownError < StandardError
+      def initialize
+        super('An unknown error has occurred. This is likely a bug you should report.')
+      end
+    end
+  end
+end

app/services/foreman_ansible_director/ansible_director_service.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module ForemanAnsibleDirector
+  class AnsibleDirectorService
+    class << self
+      include ::ForemanAnsibleDirector::Errors::Helpers
+    end
+  end
+end

app/services/foreman_ansible_director/assignment_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class AssignmentService
+  class AssignmentService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def destroy_assignment(assignment)
         ActiveRecord::Base.transaction do
@@ -23,10 +23,8 @@ def create_bulk_assignments(assignments:)
         cleared_targets = []
         ActiveRecord::Base.transaction do
           assignments.each do |assignment|
-            source_finder = ::ForemanAnsibleDirector::AssignmentService.finder(type: assignment[:source][:type])
-            target_finder = ::ForemanAnsibleDirector::AssignmentService.finder(type: assignment[:target][:type])
-            source = source_finder.find_by(id: assignment[:source][:id])
-            target = target_finder.find_by(id: assignment[:target][:id])
+            source = find_target(target_type: assignment[:source][:type], target_id: assignment[:source][:id])
+            target = find_target(target_type: assignment[:target][:type], target_id: assignment[:target][:id])
 
             unless target.id.in?(cleared_targets)
               ::ForemanAnsibleDirector::AnsibleContentAssignment.where(assignable: target).destroy_all
@@ -38,26 +36,35 @@ def create_bulk_assignments(assignments:)
       end
 
       def finder(type:)
-        case type
+        error_scope(['ADR-003-005-004-001']).try do
+          case type
 
-        when 'ACR'
-          ::ForemanAnsibleDirector::AnsibleCollectionRole
-        when 'CONTENT'
-          ::ForemanAnsibleDirector::ContentUnitVersion
-        when 'HOST'
-          Host::Managed
-        when 'HOSTGROUP'
-          Hostgroup
-        else
-          # TODO: Actual error message
-          raise "Invalid type: #{type}"
+          when 'ACR'
+            ::ForemanAnsibleDirector::AnsibleCollectionRole
+          when 'CONTENT'
+            ::ForemanAnsibleDirector::ContentUnitVersion
+          when 'HOST'
+            Host::Managed
+          when 'HOSTGROUP'
+            Hostgroup
+          else
+            raise app_error_for('ADR-003-005-004-001', args: { type: type })
+          end
         end
       end
 
       def find_target(target_type:, target_id:)
-        # TODO: Null check target
         finder = finder(type: target_type)
-        finder.find_by(id: target_id)
+        error_scope(['ADR-003-005-005-001']).try do
+          target = finder.find_by(id: target_id)
+          unless target
+            raise app_error_for('ADR-003-005-005-001', args: {
+              target_type: target_type,
+              target_id: target_id,
+            })
+          end
+          target
+        end
       end
     end
   end

app/services/foreman_ansible_director/content_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class ContentService
+  class ContentService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def create_content_unit_revision(cuv_id:,
                                        git_ref:,

app/services/foreman_ansible_director/execution_environment_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class ExecutionEnvironmentService
+  class ExecutionEnvironmentService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def create_execution_environment(name:,
                                        base_image_url:,

app/services/foreman_ansible_director/lifecycle_environment_path_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class LifecycleEnvironmentPathService
+  class LifecycleEnvironmentPathService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def create_path(name:,
                       description:,

app/services/foreman_ansible_director/lifecycle_environment_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class LifecycleEnvironmentService
+  class LifecycleEnvironmentService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def create_environment(lce_path:,
                              name:,

app/services/foreman_ansible_director/variable_service.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module ForemanAnsibleDirector
-  class VariableService
+  class VariableService < ::ForemanAnsibleDirector::AnsibleDirectorService
     class << self
       def create_variable(key:,
                           type:,

error_codes.yaml

@@ -0,0 +1,18 @@
+003:
+  description: "Internal service"
+  children:
+    005:
+      description: "AssignmentService"
+      children:
+        004:
+          description: "finder"
+          children:
+            001:
+              description: "Invalid target type"
+              details: "Raised when the target type is not supported"
+        005:
+          description: "find_target"
+          children:
+            001:
+              description: "Target not found"
+              details: "Raised when the target is not found"

test/services/unit/assignment_service_test.rb

@@ -137,11 +137,6 @@ class AssignmentServiceTest < ForemanAnsibleDirectorTestCase
             assert_equal Hostgroup, result
           end
 
-          test 'raises error for invalid type' do
-            assert_raises(RuntimeError, 'Invalid type: UNKNOWN') do
-              ::ForemanAnsibleDirector::AssignmentService.finder(type: 'UNKNOWN')
-            end
-          end
         end
 
         describe '#find_target' do
@@ -189,14 +184,6 @@ class AssignmentServiceTest < ForemanAnsibleDirectorTestCase
 
           end
 
-          test 'returns nil for non-existent target' do
-            result = ::ForemanAnsibleDirector::AssignmentService.find_target(
-              target_type: 'CONTENT',
-              target_id: -1
-            )
-
-            assert_nil result
-          end
         end
 
       end