Merge branch '52442-initial-mysql-support-removal' into 'master'

Remove dead mysql code

Closes #63191

See merge request gitlab-org/gitlab-ce!29608

10 files changed, 32 insertions, 316 deletions

diff --git a/config/application.rb b/config/application.rb
index df5079ba993..92240426b5a 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -22,11 +22,6 @@ module Gitlab
     require_dependency Rails.root.join('lib/gitlab/middleware/read_only')
     require_dependency Rails.root.join('lib/gitlab/middleware/basic_health_check')
 
-    # This needs to be loaded before DB connection is made
-    # to make sure that all connections have NO_ZERO_DATE
-    # setting disabled
-    require_dependency Rails.root.join('lib/mysql_zero_date')
-
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
diff --git a/config/database.yml.mysql b/config/database.yml.mysql
deleted file mode 100644
index 98c2abe9f5e..00000000000
--- a/config/database.yml.mysql
+++ /dev/null
@@ -1,60 +0,0 @@
-#
-# PRODUCTION
-#
-production:
-  adapter: mysql2
-  encoding: utf8
-  collation: utf8_general_ci
-  reconnect: false
-  database: gitlabhq_production
-  pool: 10
-  username: git
-  password: "secure password"
-  host: localhost
-  # socket: /tmp/mysql.sock
-
-#
-# Development specific
-#
-development:
-  adapter: mysql2
-  encoding: utf8
-  collation: utf8_general_ci
-  reconnect: false
-  database: gitlabhq_development
-  pool: 5
-  username: root
-  password: "secure password"
-  host: localhost
-  # socket: /tmp/mysql.sock
-
-#
-# Staging specific
-#
-staging:
-  adapter: mysql2
-  encoding: utf8
-  collation: utf8_general_ci
-  reconnect: false
-  database: gitlabhq_staging
-  pool: 10
-  username: git
-  password: "secure password"
-  host: localhost
-  # socket: /tmp/mysql.sock
-
-# Warning: The database defined as "test" will be erased and
-# re-generated from your development database when you run "rake".
-# Do not set this db to the same as development or production.
-test: &test
-  adapter: mysql2
-  encoding: utf8mb4
-  collation: utf8mb4_general_ci
-  reconnect: false
-  database: gitlabhq_test
-  pool: 5
-  username: root
-  password:
-  host: localhost
-  # socket: /tmp/mysql.sock
-  prepared_statements: false
diff --git a/config/initializers/active_record_data_types.rb b/config/initializers/active_record_data_types.rb
index 151bce4d130..846f28e6f66 100644
--- a/config/initializers/active_record_data_types.rb
+++ b/config/initializers/active_record_data_types.rb
@@ -1,83 +1,45 @@
 # ActiveRecord custom data type for storing datetimes with timezone information.
 # See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/11229
 
-if Gitlab::Database.postgresql?
-  require 'active_record/connection_adapters/postgresql_adapter'
+require 'active_record/connection_adapters/postgresql_adapter'
 
-  module ActiveRecord::ConnectionAdapters::PostgreSQL::OID
-    # Add the class `DateTimeWithTimeZone` so we can map `timestamptz` to it.
-    class DateTimeWithTimeZone < DateTime
-      def type
-        :datetime_with_timezone
-      end
+module ActiveRecord::ConnectionAdapters::PostgreSQL::OID
+  # Add the class `DateTimeWithTimeZone` so we can map `timestamptz` to it.
+  class DateTimeWithTimeZone < DateTime
+    def type
+      :datetime_with_timezone
     end
   end
+end
 
-  module RegisterDateTimeWithTimeZone
-    # Run original `initialize_type_map` and then register `timestamptz` as a
-    # `DateTimeWithTimeZone`.
-    #
-    # Apparently it does not matter that the original `initialize_type_map`
-    # aliases `timestamptz` to `timestamp`.
-    #
-    # When schema dumping, `timestamptz` columns will be output as
-    # `t.datetime_with_timezone`.
-    def initialize_type_map(mapping = type_map)
-      super mapping
-
-      mapping.register_type 'timestamptz' do |_, _, sql_type|
-        precision = extract_precision(sql_type)
-        ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::DateTimeWithTimeZone.new(precision: precision)
-      end
-    end
-  end
-
-  class ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
-    prepend RegisterDateTimeWithTimeZone
-
-    # Add column type `datetime_with_timezone` so we can do this in
-    # migrations:
-    #
-    #   add_column(:users, :datetime_with_timezone)
-    #
-    NATIVE_DATABASE_TYPES[:datetime_with_timezone] = { name: 'timestamptz' }
-  end
-elsif Gitlab::Database.mysql?
-  require 'active_record/connection_adapters/mysql2_adapter'
-
-  module RegisterDateTimeWithTimeZone
-    # Run original `initialize_type_map` and then register `timestamp` as a
-    # `MysqlDateTimeWithTimeZone`.
-    #
-    # When schema dumping, `timestamp` columns will be output as
-    # `t.datetime_with_timezone`.
-    def initialize_type_map(mapping = type_map)
-      super mapping
-
-      mapping.register_type(/timestamp/i) do |sql_type|
-        precision = extract_precision(sql_type)
-        ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter::MysqlDateTimeWithTimeZone.new(precision: precision)
-      end
+module RegisterDateTimeWithTimeZone
+  # Run original `initialize_type_map` and then register `timestamptz` as a
+  # `DateTimeWithTimeZone`.
+  #
+  # Apparently it does not matter that the original `initialize_type_map`
+  # aliases `timestamptz` to `timestamp`.
+  #
+  # When schema dumping, `timestamptz` columns will be output as
+  # `t.datetime_with_timezone`.
+  def initialize_type_map(mapping = type_map)
+    super mapping
+
+    mapping.register_type 'timestamptz' do |_, _, sql_type|
+      precision = extract_precision(sql_type)
+      ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::DateTimeWithTimeZone.new(precision: precision)
     end
   end
+end
 
-  class ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter
-    prepend RegisterDateTimeWithTimeZone
-
-    # Add the class `DateTimeWithTimeZone` so we can map `timestamp` to it.
-    class MysqlDateTimeWithTimeZone < ActiveRecord::Type::DateTime
-      def type
-        :datetime_with_timezone
-      end
-    end
+class ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
+  prepend RegisterDateTimeWithTimeZone
 
-    # Add column type `datetime_with_timezone` so we can do this in
-    # migrations:
-    #
-    #   add_column(:users, :datetime_with_timezone)
-    #
-    NATIVE_DATABASE_TYPES[:datetime_with_timezone] = { name: 'timestamp' }
-  end
+  # Add column type `datetime_with_timezone` so we can do this in
+  # migrations:
+  #
+  #   add_column(:users, :datetime_with_timezone)
+  #
+  NATIVE_DATABASE_TYPES[:datetime_with_timezone] = { name: 'timestamptz' }
 end
 
 # Ensure `datetime_with_timezone` columns are correctly written to schema.rb
diff --git a/config/initializers/active_record_mysql_timestamp.rb b/config/initializers/active_record_mysql_timestamp.rb
deleted file mode 100644
index af74c4ff6fb..00000000000
--- a/config/initializers/active_record_mysql_timestamp.rb
+++ /dev/null
@@ -1,30 +0,0 @@
-# Make sure that MySQL won't try to use CURRENT_TIMESTAMP when the timestamp
-# column is NOT NULL. See https://gitlab.com/gitlab-org/gitlab-ce/issues/36405
-# And also: https://bugs.mysql.com/bug.php?id=75098
-# This patch was based on:
-# https://github.com/rails/rails/blob/15ef55efb591e5379486ccf53dd3e13f416564f6/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb#L34-L36
-
-if Gitlab::Database.mysql?
-  require 'active_record/connection_adapters/abstract/schema_creation'
-
-  module MySQLTimestampFix
-    def add_column_options!(sql, options)
-      # By default, TIMESTAMP columns are NOT NULL, cannot contain NULL values,
-      # and assigning NULL assigns the current timestamp. To permit a TIMESTAMP
-      # column to contain NULL, explicitly declare it with the NULL attribute.
-      # See http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html
-      if sql.end_with?('timestamp') && !options[:primary_key]
-        if options[:null] != false
-          sql << ' NULL'
-        elsif options[:column].default.nil?
-          sql << ' DEFAULT 0'
-        end
-      end
-
-      super
-    end
-  end
-
-  ActiveRecord::ConnectionAdapters::AbstractAdapter::SchemaCreation
-    .prepend(MySQLTimestampFix)
-end
diff --git a/config/initializers/ar_mysql_jsonb_support.rb b/config/initializers/ar_mysql_jsonb_support.rb
deleted file mode 100644
index 63a0b05119a..00000000000
--- a/config/initializers/ar_mysql_jsonb_support.rb
+++ /dev/null
@@ -1,31 +0,0 @@
-# frozen_string_literal: true
-
-require 'active_record/connection_adapters/abstract_mysql_adapter'
-require 'active_record/connection_adapters/mysql/schema_definitions'
-
-# MySQL (5.6) and MariaDB (10.1) are currently supported versions within GitLab,
-# Since they do not support native `json` datatype we force to emulate it as `text`
-
-if Gitlab::Database.mysql?
-  module ActiveRecord
-    module ConnectionAdapters
-      class AbstractMysqlAdapter
-        JSON_DATASIZE = 1.megabyte
-
-        NATIVE_DATABASE_TYPES.merge!(
-          json: { name: "text", limit: JSON_DATASIZE },
-          jsonb: { name: "text", limit: JSON_DATASIZE }
-        )
-      end
-
-      module MySQL
-        module ColumnMethods
-          # We add `jsonb` helper, as `json` is already defined for `MySQL` since Rails 5
-          def jsonb(*args, **options)
-            args.each { |name| column(name, :json, options) }
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/config/initializers/ar_native_database_types.rb b/config/initializers/ar_native_database_types.rb
deleted file mode 100644
index 6d397661f75..00000000000
--- a/config/initializers/ar_native_database_types.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'active_record/connection_adapters/abstract_mysql_adapter'
-
-module ActiveRecord
-  module ConnectionAdapters
-    class AbstractMysqlAdapter
-      NATIVE_DATABASE_TYPES.merge!(
-        bigserial: { name: 'bigint(20) auto_increment PRIMARY KEY' },
-        serial: { name: 'int auto_increment PRIMARY KEY' }
-      )
-    end
-  end
-end
diff --git a/config/initializers/connection_fix.rb b/config/initializers/connection_fix.rb
deleted file mode 100644
index d0b1444f607..00000000000
--- a/config/initializers/connection_fix.rb
+++ /dev/null
@@ -1,32 +0,0 @@
-# from http://gist.github.com/238999
-#
-# If your workers are inactive for a long period of time, they'll lose
-# their MySQL connection.
-#
-# This hack ensures we re-connect whenever a connection is
-# lost. Because, really. why not?
-#
-# Stick this in RAILS_ROOT/config/initializers/connection_fix.rb (or somewhere similar)
-#
-# From:
-#   http://coderrr.wordpress.com/2009/01/08/activerecord-threading-issues-and-resolutions/
-
-if defined?(ActiveRecord::ConnectionAdapters::Mysql2Adapter)
-  module ActiveRecord::ConnectionAdapters
-    class Mysql2Adapter
-      alias_method :execute_without_retry, :execute
-
-      def execute(*args)
-        execute_without_retry(*args)
-      rescue ActiveRecord::StatementInvalid => e
-        if e.message =~ /server has gone away/i
-          warn "Lost connection to MySQL server during query"
-          reconnect!
-          retry
-        else
-          raise e
-        end
-      end
-    end
-  end
-end
diff --git a/config/initializers/mysql_ignore_postgresql_options.rb b/config/initializers/mysql_ignore_postgresql_options.rb
deleted file mode 100644
index e6a7d9bef52..00000000000
--- a/config/initializers/mysql_ignore_postgresql_options.rb
+++ /dev/null
@@ -1,42 +0,0 @@
-# This patches ActiveRecord so indexes created using the MySQL adapter ignore
-# any PostgreSQL specific options (e.g. `using: :gin`).
-#
-# These patches do the following for MySQL:
-#
-# 1. Indexes created using the :opclasses option are ignored (as they serve no
-#    purpose on MySQL).
-# 2. When creating an index with `using: :gin` the `using` option is discarded
-#    as :gin is not a valid value for MySQL.
-# 3. The `:opclasses` option is stripped from add_index_options in case it's
-#    used anywhere other than in the add_index methods.
-
-if defined?(ActiveRecord::ConnectionAdapters::Mysql2Adapter)
-  module ActiveRecord
-    module ConnectionAdapters
-      class Mysql2Adapter < AbstractMysqlAdapter
-        alias_method :__gitlab_add_index, :add_index
-        alias_method :__gitlab_add_index_options, :add_index_options
-
-        def add_index(table_name, column_name, options = {})
-          unless options[:opclasses]
-            __gitlab_add_index(table_name, column_name, options)
-          end
-        end
-
-        def add_index_options(table_name, column_name, options = {})
-          if options[:using] && options[:using] == :gin
-            options = options.dup
-            options.delete(:using)
-          end
-
-          if options[:opclasses]
-            options = options.dup
-            options.delete(:opclasses)
-          end
-
-          __gitlab_add_index_options(table_name, column_name, options)
-        end
-      end
-    end
-  end
-end
diff --git a/config/initializers/mysql_set_length_for_binary_indexes.rb b/config/initializers/mysql_set_length_for_binary_indexes.rb
deleted file mode 100644
index 552f3a20a95..00000000000
--- a/config/initializers/mysql_set_length_for_binary_indexes.rb
+++ /dev/null
@@ -1,30 +0,0 @@
-# This patches ActiveRecord so indexes for binary columns created using the
-# MySQL adapter apply a length of 20. Otherwise MySQL can't create an index on
-# binary columns.
-
-module MysqlSetLengthForBinaryIndexAndIgnorePostgresOptionsForSchema
-  # This method is used in Rails 5 schema loading as t.index
-  def index(column_names, options = {})
-    # Ignore indexes that use opclasses,
-    # also see config/initializers/mysql_ignore_postgresql_options.rb
-    if options[:opclasses]
-      warn "WARNING: index on columns #{column_names} uses unsupported option, skipping."
-      return
-    end
-
-    options[:length] ||= {}
-    Array(column_names).each do |column_name|
-      column = columns.find { |c| c.name == column_name }
-
-      if column&.type == :binary
-        options[:length][column_name] = 20
-      end
-    end
-
-    super(column_names, options)
-  end
-end
-
-if defined?(ActiveRecord::ConnectionAdapters::MySQL::TableDefinition)
-  ActiveRecord::ConnectionAdapters::MySQL::TableDefinition.send(:prepend, MysqlSetLengthForBinaryIndexAndIgnorePostgresOptionsForSchema)
-end
diff --git a/config/initializers/peek.rb b/config/initializers/peek.rb
index 2aec32e878c..1ffd133239d 100644
--- a/config/initializers/peek.rb
+++ b/config/initializers/peek.rb
@@ -2,11 +2,7 @@ Rails.application.config.peek.adapter = :redis, { client: ::Redis.new(Gitlab::Re
 
 Peek.into Peek::Views::Host
 
-if Gitlab::Database.mysql?
-  require 'peek-mysql2'
-  PEEK_DB_CLIENT = ::Mysql2::Client
-  PEEK_DB_VIEW = Peek::Views::Mysql2
-elsif Gitlab::Database.postgresql?
+if Gitlab::Database.postgresql?
   require 'peek-pg'
   PEEK_DB_CLIENT = ::PG::Connection
   PEEK_DB_VIEW = Peek::Views::PG