Remove service binding unique constraints to allow multiple bindings

Author: johha

db/migrations/20250731071027_allow_multiple_service_bindings.rb

@@ -0,0 +1,55 @@
+Sequel.migration do
+  no_transaction # adding an index concurrently cannot be done within a transaction
+
+  up do
+    alter_table(:service_bindings) do
+      drop_constraint(:unique_service_binding_service_instance_guid_app_guid) if @db.indexes(:service_bindings).key?(:unique_service_binding_service_instance_guid_app_guid)
+      drop_constraint(:unique_service_binding_app_guid_name) if @db.indexes(:service_bindings).key?(:unique_service_binding_app_guid_name)
+    end
+
+    if database_type == :postgres
+      VCAP::Migration.with_concurrent_timeout(self) do
+        add_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, concurrently: true, if_not_exists: true
+        add_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, concurrently: true, if_not_exists: true
+      end
+    elsif database_type == :mysql
+      alter_table(:service_bindings) do
+        # rubocop:disable Sequel/ConcurrentIndex
+        unless @db.indexes(:service_bindings).key?(:service_bindings_app_guid_service_instance_guid_index)
+          add_index %i[app_guid service_instance_guid],
+                    name: :service_bindings_app_guid_service_instance_guid_index
+        end
+        add_index %i[app_guid name], name: :service_bindings_app_guid_name_index unless @db.indexes(:service_bindings).key?(:service_bindings_app_guid_name_index)
+        # rubocop:enable Sequel/ConcurrentIndex
+      end
+    end
+  end
+
+  down do
+    alter_table(:service_bindings) do
+      if @db.indexes(:service_bindings)[:unique_service_binding_service_instance_guid_app_guid].blank?
+        add_unique_constraint %i[service_instance_guid app_guid],
+                              name: :unique_service_binding_service_instance_guid_app_guid
+      end
+    end
+    alter_table(:service_bindings) do
+      add_unique_constraint %i[app_guid name], name: :unique_service_binding_app_guid_name if @db.indexes(:service_bindings)[:unique_service_binding_app_guid_name].blank?
+    end
+
+    if database_type == :postgres
+      VCAP::Migration.with_concurrent_timeout(self) do
+        drop_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, concurrently: true, if_exists: true
+        drop_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, concurrently: true, if_exists: true
+      end
+    elsif database_type == :mysql
+      alter_table(:service_bindings) do
+        # rubocop:disable Sequel/ConcurrentIndex
+        if @db.indexes(:service_bindings).key?(:service_bindings_app_guid_service_instance_guid_index)
+          drop_index %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index
+        end
+        drop_index %i[app_guid name], name: :service_bindings_app_guid_name_index if @db.indexes(:service_bindings).key?(:service_bindings_app_guid_name_index)
+        # rubocop:enable Sequel/ConcurrentIndex
+      end
+    end
+  end
+end

spec/migrations/20250731071027_allow_multiple_service_bindings_spec.rb

@@ -0,0 +1,69 @@
+require 'spec_helper'
+require 'migrations/helpers/migration_shared_context'
+
+RSpec.describe 'migration to allow multiple service bindings', isolation: :truncation, type: :migration do
+  include_context 'migration' do
+    let(:migration_filename) { '20250731071027_allow_multiple_service_bindings.rb' }
+  end
+
+  describe 'service_bindings table' do
+    context 'up migration' do
+      it 'is in the correct state before migration' do
+        expect(db.indexes(:service_bindings)).to include(:unique_service_binding_service_instance_guid_app_guid)
+        expect(db.indexes(:service_bindings)).to include(:unique_service_binding_app_guid_name)
+        expect(db.indexes(:service_bindings)).not_to include(:service_bindings_app_guid_service_instance_guid_index)
+        expect(db.indexes(:service_bindings)).not_to include(:service_bindings_app_guid_name_index)
+      end
+
+      it 'migrates successfully' do
+        expect { Sequel::Migrator.run(db, migrations_path, target: current_migration_index, allow_missing_migration_files: true) }.not_to raise_error
+        expect(db.indexes(:service_bindings)).not_to include(:unique_service_binding_app_guid_name)
+        expect(db.indexes(:service_bindings)).not_to include(:unique_service_binding_service_instance_guid_app_guid)
+        expect(db.indexes(:service_bindings)).to include(:service_bindings_app_guid_service_instance_guid_index)
+        expect(db.indexes(:service_bindings)).to include(:service_bindings_app_guid_name_index)
+      end
+
+      it 'does not fail if indexes/constraints are already in desired state' do
+        db.alter_table :service_bindings do
+          drop_constraint :unique_service_binding_service_instance_guid_app_guid
+          drop_constraint :unique_service_binding_app_guid_name
+        end
+        if db.database_type == :postgres
+          db.add_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, if_not_exists: true, concurrently: true
+          db.add_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, if_not_exists: true, concurrently: true
+        else
+          db.add_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, if_not_exists: true
+          db.add_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, if_not_exists: true
+        end
+        expect { Sequel::Migrator.run(db, migrations_path, target: current_migration_index, allow_missing_migration_files: true) }.not_to raise_error
+      end
+    end
+
+    context 'down migration' do
+      it 'rolls back successfully' do
+        expect { Sequel::Migrator.run(db, migrations_path, target: current_migration_index - 1, allow_missing_migration_files: true) }.not_to raise_error
+        expect(db.indexes(:service_bindings)).to include(:unique_service_binding_service_instance_guid_app_guid)
+        expect(db.indexes(:service_bindings)).to include(:unique_service_binding_app_guid_name)
+        expect(db.indexes(:service_bindings)).not_to include(:service_bindings_app_guid_service_instance_guid_index)
+        expect(db.indexes(:service_bindings)).not_to include(:service_bindings_app_guid_name_index)
+      end
+
+      it 'does not fail if indexes/constraints are already in desired state' do
+        expect { Sequel::Migrator.run(db, migrations_path, target: current_migration_index, allow_missing_migration_files: true) }.not_to raise_error
+        db.alter_table :service_bindings do
+          add_unique_constraint %i[service_instance_guid app_guid], name: :unique_service_binding_service_instance_guid_app_guid
+          add_unique_constraint %i[app_guid name], name: :unique_service_binding_app_guid_name
+        end
+        if db.database_type == :postgres
+          db.drop_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, if_exists: true, concurrently: true
+          db.drop_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, if_exists: true, concurrently: true
+        else
+          db.drop_index :service_bindings, %i[app_guid service_instance_guid], name: :service_bindings_app_guid_service_instance_guid_index, if_exists: true
+          db.drop_index :service_bindings, %i[app_guid name], name: :service_bindings_app_guid_name_index, if_exists: true
+        end
+
+        expect { Sequel::Migrator.run(db, migrations_path, target: current_migration_index - 1, allow_missing_migration_files: true) }.not_to raise_error
+      end
+    end
+  end
+end