Add default ORDER BY id to Sequel model queries

app/models/runtime/buildpack_lifecycle_data_model.rb

@@ -28,8 +28,7 @@ class BuildpackLifecycleDataModel < Sequel::Model(:buildpack_lifecycle_data)
     one_to_many :buildpack_lifecycle_buildpacks,
                 class: '::VCAP::CloudController::BuildpackLifecycleBuildpackModel',
                 key: :buildpack_lifecycle_data_guid,
-                primary_key: :guid,
-                order: :id
+                primary_key: :guid
     plugin :nested_attributes
     nested_attributes :buildpack_lifecycle_buildpacks, destroy: true
     add_association_dependencies buildpack_lifecycle_buildpacks: :destroy

app/models/runtime/cnb_lifecycle_data_model.rb

@@ -27,8 +27,7 @@ class CNBLifecycleDataModel < Sequel::Model(:cnb_lifecycle_data)
     one_to_many :buildpack_lifecycle_buildpacks,
                 class: '::VCAP::CloudController::BuildpackLifecycleBuildpackModel',
                 key: :cnb_lifecycle_data_guid,
-                primary_key: :guid,
-                order: :id
+                primary_key: :guid
     plugin :nested_attributes
     nested_attributes :buildpack_lifecycle_buildpacks, destroy: true
     add_association_dependencies buildpack_lifecycle_buildpacks: :destroy

lib/cloud_controller/db.rb

@@ -5,6 +5,7 @@
 require 'cloud_controller/execution_context'
 require 'sequel/extensions/query_length_logging'
 require 'sequel/extensions/request_query_metrics'
+require 'sequel/extensions/default_order_by_id'
 
 module VCAP::CloudController
   class DB
@@ -45,6 +46,7 @@ def self.connect(opts, logger)
       add_connection_expiration_extension(db, opts)
       add_connection_validator_extension(db, opts)
       db.extension(:requires_unique_column_names_in_subquery)
+      db.extension(:default_order_by_id)
       add_connection_metrics_extension(db)
       db
     end

lib/cloud_controller/diego/constants.rb

@@ -1,3 +1,5 @@
+require 'diego/lrp_constants'
+
 module VCAP::CloudController
   module Diego
     STAGING_DOMAIN                   = 'cf-app-staging'.freeze

lib/cloud_controller/diego/reporters/instances_reporter.rb

@@ -1,6 +1,6 @@
 require 'utils/workpool'
+require 'cloud_controller/diego/constants'
 require 'cloud_controller/diego/reporters/reporter_mixins'
-require 'diego/lrp_constants'
 
 module VCAP::CloudController
   module Diego

lib/sequel/extensions/default_order_by_id.rb

@@ -0,0 +1,134 @@
+# frozen_string_literal: true
+
+# Sequel extension that adds default ORDER BY id to model queries.
+#
+# Hooks into fetch methods (all, each, first) to add ORDER BY id just before
+# execution. This ensures ordering is only added to the final query, not to
+# subqueries or compound query parts.
+#
+# Skips default ordering when:
+# - Query already has explicit ORDER BY
+# - Query is incompatible (GROUP BY, compounds, DISTINCT ON, from_self)
+# - Query is schema introspection (LIMIT 0)
+# - Model doesn't have id as primary key
+# - id is not in the select list
+#
+# For JOIN queries with SELECT *, uses qualified column (table.id) to avoid
+# ambiguity.
+#
+# Ensures deterministic query results for consistent API responses and
+# reliable test behavior.
+#
+# Usage:
+#   DB.extension(:default_order_by_id)
+#
+module Sequel
+  module DefaultOrderById
+    module DatasetMethods
+      def all(*, &)
+        id_col = id_column_for_order
+        return super unless id_col
+
+        order(id_col).all(*, &)
+      end
+
+      def each(*, &)
+        id_col = id_column_for_order
+        return super unless id_col
+
+        order(id_col).each(*, &)
+      end
+
+      def first(*, &)
+        id_col = id_column_for_order
+        return super unless id_col
+
+        order(id_col).first(*, &)
+      end
+
+      private
+
+      def id_column_for_order
+        return if already_ordered? || incompatible_with_order? || not_a_data_query? || !model_has_id_primary_key?
+
+        find_id_column
+      end
+
+      def already_ordered?
+        opts[:order]
+      end
+
+      def incompatible_with_order?
+        opts[:group] ||       # Aggregated results don't have individual ids
+          opts[:compounds] || # Compound queries (e.g. UNION) have own ordering
+          distinct_on? ||     # DISTINCT ON requires matching ORDER BY
+          from_self?          # Outer query handles ordering
+      end
+
+      def distinct_on?
+        opts[:distinct].is_a?(Array) && opts[:distinct].any?
+      end
+
+      def from_self?
+        opts[:from].is_a?(Array) && opts[:from].any? { |f| f.is_a?(Sequel::SQL::AliasedExpression) }
+      end
+
+      def not_a_data_query?
+        opts[:limit] == 0 # Schema introspection query
+      end
+
+      def model_has_id_primary_key?
+        return false unless respond_to?(:model) && model
+
+        model.primary_key == :id
+      end
+
+      def find_id_column
+        select_cols = opts[:select]
+
+        if select_cols.nil? || select_cols.empty?
+          # SELECT * includes id
+          if opts[:join]
+            # Qualify to avoid ambiguity with joined tables
+            return Sequel.qualify(model.table_name, :id)
+          end
+
+          return :id
+        end
+
+        select_cols.each do |col|
+          # SELECT table.* includes id
+          return :id if col.is_a?(Sequel::SQL::ColumnAll) && col.table == model.table_name
+
+          id_col = extract_id_column(col)
+          return id_col if id_col
+        end
+
+        nil
+      end
+
+      def extract_id_column(col)
+        return col if id_expression?(col)
+
+        return col.alias if col.is_a?(Sequel::SQL::AliasedExpression) && id_expression?(col.expression)
+
+        nil
+      end
+
+      def id_expression?(expr)
+        case expr
+        when Symbol
+          expr == :id || expr.to_s.end_with?('__id')
+        when Sequel::SQL::Identifier
+          expr.value == :id
+        when Sequel::SQL::QualifiedIdentifier
+          expr.column == :id
+        else
+          false
+        end
+      end
+    end
+  end
+
+  Dataset.register_extension(:default_order_by_id, DefaultOrderById::DatasetMethods)
+end

spec/lightweight_db_spec_helper.rb

@@ -0,0 +1,5 @@
+require 'lightweight_spec_helper'
+require 'sequel'
+require 'support/bootstrap/db_connection_string'
+
+DB = Sequel.connect(DbConnectionString.new.to_s)

spec/support/bootstrap/db_config.rb

@@ -1,9 +1,10 @@
 require 'cloud_controller/db'
 require 'cloud_controller/database_parts_parser'
+require_relative 'db_connection_string'
 
 class DbConfig
   def initialize(connection_string: ENV.fetch('DB_CONNECTION_STRING', nil), db_type: ENV.fetch('DB', nil))
-    @connection_string = connection_string || default_connection_string(db_type || 'postgres')
+    @connection_string = DbConnectionString.new(connection_string: connection_string, db_type: db_type).to_s
     initialize_environment_for_cc_spawning
   end
 
@@ -49,25 +50,4 @@ def self.reset_environment
   def initialize_environment_for_cc_spawning
     ENV['DB_CONNECTION_STRING'] = connection_string
   end
-
-  def default_connection_string(db_type)
-    "#{default_connection_prefix(db_type)}/#{default_name}"
-  end
-
-  def default_connection_prefix(db_type)
-    default_connection_prefixes = {
-      'mysql' => ENV['MYSQL_CONNECTION_PREFIX'] || 'mysql2://root:password@localhost:3306',
-      'postgres' => ENV['POSTGRES_CONNECTION_PREFIX'] || 'postgres://postgres@localhost:5432'
-    }
-
-    default_connection_prefixes[db_type]
-  end
-
-  def default_name
-    if ENV['TEST_ENV_NUMBER'].presence
-      "cc_test_#{ENV.fetch('TEST_ENV_NUMBER')}"
-    else
-      'cc_test_1'
-    end
-  end
 end

spec/support/bootstrap/db_connection_string.rb

@@ -0,0 +1,30 @@
+class DbConnectionString
+  def initialize(connection_string: ENV.fetch('DB_CONNECTION_STRING', nil), db_type: ENV.fetch('DB', nil))
+    @connection_string = connection_string || default_connection_string(db_type || 'postgres')
+  end
+
+  def to_s
+    @connection_string
+  end
+
+  private
+
+  def default_connection_string(db_type)
+    "#{default_connection_prefix(db_type)}/#{default_name}"
+  end
+
+  def default_connection_prefix(db_type)
+    {
+      'mysql' => ENV['MYSQL_CONNECTION_PREFIX'] || 'mysql2://root:password@localhost:3306',
+      'postgres' => ENV['POSTGRES_CONNECTION_PREFIX'] || 'postgres://postgres@localhost:5432'
+    }.fetch(db_type)
+  end
+
+  def default_name
+    if ENV['TEST_ENV_NUMBER'].to_s.empty?
+      'cc_test_1'
+    else
+      "cc_test_#{ENV.fetch('TEST_ENV_NUMBER')}"
+    end
+  end
+end