bigint migration - events table - step 1

Author: philippthun

.rubocop_cc.yml

@@ -136,8 +136,8 @@ Rails/DangerousColumnNames: # Disabled, in comparison to active_record we need t
 Rails/SkipsModelValidations: # We don`t want any model at all in migrations and migration specs
   Enabled: true
   Exclude:
-    - db/migrations/*
-    - spec/migrations/*
+    - db/migrations/**/*
+    - spec/migrations/**/*
 
 #### ENABLED SECTION
 Gemspec/DeprecatedAttributeAssignment:

db/helpers/bigint_migration.rb

@@ -0,0 +1,48 @@
+require 'tasks/rake_config'
+
+# helpers
+def opt_out?
+  opt_out = RakeConfig.config.get(:skip_bigint_id_migration)
+  opt_out.nil? ? false : opt_out
+rescue VCAP::CloudController::Config::InvalidConfigPath
+  false
+end
+
+# DSL
+def empty?(table)
+  raise unless is_a?(Sequel::Database)
+
+  self[table].count == 0
+end
+
+def change_pk_to_bigint(table)
+  raise unless is_a?(Sequel::Database)
+
+  set_column_type(table, :id, :Bignum) if column_type(self, table, :id) != BIGINT_TYPE
+end
+
+def add_bigint_column(table)
+  raise unless is_a?(Sequel::Database)
+
+  add_column(table, :id_bigint, :Bignum, if_not_exists: true)
+end
+
+def revert_pk_to_integer(table)
+  raise unless is_a?(Sequel::Database)
+
+  set_column_type(table, :id, :integer) if column_type(self, table, :id) == BIGINT_TYPE
+end
+
+def drop_bigint_column(table)
+  raise unless is_a?(Sequel::Database)
+
+  drop_column(table, :id_bigint, if_exists: true)
+end
+
+# internal constants
+BIGINT_TYPE = 'bigint'.freeze
+
+# internal helpers
+def column_type(db, table, column)
+  db.schema(table).find { |col, _| col == column }&.dig(1, :db_type)
+end

db/migrations/20250327142351_bigint_migration_events_step1.rb

@@ -0,0 +1,18 @@
+require File.expand_path('../helpers/bigint_migration', __dir__)
+
+Sequel.migration do
+  up do
+    unless opt_out?
+      if empty?(:events)
+        change_pk_to_bigint(:events)
+      else
+        add_bigint_column(:events)
+      end
+    end
+  end
+
+  down do
+    revert_pk_to_integer(:events)
+    drop_bigint_column(:events)
+  end
+end

lib/cloud_controller/config_schemas/base/migrate_schema.rb

@@ -10,6 +10,7 @@ class MigrateSchema < VCAP::Config
             optional(:max_migration_statement_runtime_in_seconds) => Integer,
             optional(:migration_psql_concurrent_statement_timeout_in_seconds) => Integer,
             optional(:migration_psql_worker_memory_kb) => Integer,
+            optional(:skip_bigint_id_migration) => bool,
 
             db: {
               optional(:database) => Hash, # db connection hash for sequel

spec/migrations/20250327142351_bigint_migration_events_step1_spec.rb

@@ -0,0 +1,16 @@
+require 'spec_helper'
+require 'migrations/helpers/bigint_migration_step1_shared_context'
+
+RSpec.describe 'bigint migration - events table - step1', isolation: :truncation, type: :migration do
+  include_context 'bigint migration step1' do
+    let(:migration_filename) { '20250327142351_bigint_migration_events_step1.rb' }
+    let(:table) { :events }
+    let(:insert_hash) do
+      {
+        guid: 'guid', timestamp: Time.now.utc, type: 'type',
+        actor: 'actor', actor_type: 'actor_type',
+        actee: 'actee', actee_type: 'actee_type'
+      }
+    end
+  end
+end

spec/migrations/bigint_migration_helpers_spec.rb

@@ -0,0 +1,48 @@
+require 'spec_helper'
+require_relative '../../db/helpers/bigint_migration'
+
+RSpec.describe 'bigint migration helpers', isolation: :truncation, type: :migration do
+  let(:fake_config) { double }
+  let(:skip_bigint_id_migration) { nil }
+
+  before do
+    allow(fake_config).to receive(:get).with(:skip_bigint_id_migration).and_return(skip_bigint_id_migration)
+    allow(RakeConfig).to receive(:config).and_return(fake_config)
+  end
+
+  describe '#opt_out?' do
+    context 'when skip_bigint_id_migration is false' do
+      let(:skip_bigint_id_migration) { false }
+
+      it 'returns false' do
+        expect(opt_out?).to be(false)
+      end
+    end
+
+    context 'when skip_bigint_id_migration is true' do
+      let(:skip_bigint_id_migration) { true }
+
+      it 'returns true' do
+        expect(opt_out?).to be(true)
+      end
+    end
+
+    context 'when skip_bigint_id_migration is nil' do
+      let(:skip_bigint_id_migration) { nil }
+
+      it 'returns false' do
+        expect(opt_out?).to be(false)
+      end
+    end
+
+    context 'when raising InvalidConfigPath error' do
+      before do
+        allow(fake_config).to receive(:get).with(:skip_bigint_id_migration).and_raise(VCAP::CloudController::Config::InvalidConfigPath)
+      end
+
+      it 'returns false' do
+        expect(opt_out?).to be(false)
+      end
+    end
+  end
+end

spec/migrations/helpers/bigint_migration_step1_shared_context.rb

@@ -0,0 +1,81 @@
+require 'migrations/helpers/migration_shared_context'
+
+RSpec.shared_context 'bigint migration step1' do
+  subject(:run_migration) { Sequel::Migrator.run(db, migrations_path, target: current_migration_index, allow_missing_migration_files: true) }
+
+  include_context 'migration'
+
+  let(:skip_bigint_id_migration) { nil }
+
+  before do
+    fake_config = double
+    allow(fake_config).to receive(:get).with(:skip_bigint_id_migration).and_return(skip_bigint_id_migration)
+    allow(RakeConfig).to receive(:config).and_return(fake_config)
+  end
+
+  describe 'up' do
+    context 'when skip_bigint_id_migration is false' do
+      let(:skip_bigint_id_migration) { false }
+
+      context 'when the table is empty' do
+        before do
+          db[table].delete
+        end
+
+        it "changes the id column's type to bigint" do
+          expect(db).to have_table_with_column_and_type(table, :id, 'integer')
+
+          run_migration
+
+          expect(db).to have_table_with_column_and_type(table, :id, 'bigint')
+        end
+
+        it 'does not add the id_bigint column' do
+          expect(db).not_to have_table_with_column(table, :id_bigint)
+
+          run_migration
+
+          expect(db).not_to have_table_with_column(table, :id_bigint)
+        end
+      end
+
+      context 'when the table is not empty' do
+        before do
+          db[table].insert(insert_hash)
+        end
+
+        it "does not change the id column's type" do
+          expect(db).to have_table_with_column_and_type(table, :id, 'integer')
+
+          run_migration
+
+          expect(db).to have_table_with_column_and_type(table, :id, 'integer')
+        end
+
+        it 'adds the id_bigint column' do
+          expect(db).not_to have_table_with_column(table, :id_bigint)
+
+          run_migration
+
+          expect(db).to have_table_with_column_and_type(table, :id_bigint, 'bigint')
+        end
+      end
+    end
+
+    context 'when skip_bigint_id_migration is true' do
+      let(:skip_bigint_id_migration) { true }
+
+      it "neither changes the id column's type, nor adds the id_bigint column" do
+        expect(db).to have_table_with_column_and_type(table, :id, 'integer')
+        expect(db).not_to have_table_with_column(table, :id_bigint)
+
+        run_migration
+
+        expect(db).to have_table_with_column_and_type(table, :id, 'integer')
+        expect(db).not_to have_table_with_column(table, :id_bigint)
+      end
+    end
+  end
+
+  # down
+end

spec/migrations/helpers/matchers.rb

@@ -15,3 +15,17 @@
     !options.delete(:name).nil? && (options - %i[if_exists concurrently]).empty?
   end
 end
+
+RSpec::Matchers.define :have_table_with_column do |table, column|
+  match do |db|
+    db[table].columns.include?(column)
+  end
+end
+
+RSpec::Matchers.define :have_table_with_column_and_type do |table, column, type|
+  match do |db|
+    expect(db).to have_table_with_column(table, column)
+
+    db.schema(table).find { |col, _| col == column }&.dig(1, :db_type) == type
+  end
+end