Move migration to background

2 files changed, 313 insertions, 284 deletions

diff --git a/db/post_migrate/20170921101004_normalize_ldap_extern_uids.rb b/db/post_migrate/20170921101004_normalize_ldap_extern_uids.rb
index 234e8a3270b..2230bb0e53c 100644
--- a/db/post_migrate/20170921101004_normalize_ldap_extern_uids.rb
+++ b/db/post_migrate/20170921101004_normalize_ldap_extern_uids.rb
@@ -5,297 +5,22 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
   include Gitlab::Database::MigrationHelpers
 
   DOWNTIME = false
+  MIGRATION = 'NormalizeLdapExternUidsRange'.freeze
+  DELAY_INTERVAL = 10.seconds
 
-  class Identity < ActiveRecord::Base
-    self.table_name = 'identities'
-  end
-
-  # Copied this class to make this migration resilient to future code changes.
-  # And if the normalize behavior is changed in the future, it must be
-  # accompanied by another migration.
-  module Gitlab
-    module LDAP
-      MalformedDnError = Class.new(StandardError)
-      UnsupportedDnFormatError = Class.new(StandardError)
-
-      class DN
-        def self.normalize_value(given_value)
-          dummy_dn = "placeholder=#{given_value}"
-          normalized_dn = new(*dummy_dn).to_normalized_s
-          normalized_dn.sub(/\Aplaceholder=/, '')
-        end
-
-        ##
-        # Initialize a DN, escaping as required. Pass in attributes in name/value
-        # pairs. If there is a left over argument, it will be appended to the dn
-        # without escaping (useful for a base string).
-        #
-        # Most uses of this class will be to escape a DN, rather than to parse it,
-        # so storing the dn as an escaped String and parsing parts as required
-        # with a state machine seems sensible.
-        def initialize(*args)
-          @dn = if args.length > 1
-                  initialize_array(args)
-                else
-                  initialize_string(args[0])
-                end
-        end
-
-        def initialize_array(args)
-          buffer = StringIO.new
-
-          args.each_with_index do |arg, index|
-            if index.even? # key
-              buffer << "," if index > 0
-              buffer << arg
-            else # value
-              buffer << "="
-              buffer << self.class.escape(arg)
-            end
-          end
-
-          buffer.string
-        end
-
-        def initialize_string(arg)
-          arg.to_s
-        end
-
-        ##
-        # Parse a DN into key value pairs using ASN from
-        # http://tools.ietf.org/html/rfc2253 section 3.
-        # rubocop:disable Metrics/AbcSize
-        # rubocop:disable Metrics/CyclomaticComplexity
-        # rubocop:disable Metrics/PerceivedComplexity
-        def each_pair
-          state = :key
-          key = StringIO.new
-          value = StringIO.new
-          hex_buffer = ""
-
-          @dn.each_char.with_index do |char, dn_index|
-            case state
-            when :key then
-              case char
-              when 'a'..'z', 'A'..'Z' then
-                state = :key_normal
-                key << char
-              when '0'..'9' then
-                state = :key_oid
-                key << char
-              when ' ' then state = :key
-              else raise(MalformedDnError, "Unrecognized first character of an RDN attribute type name \"#{char}\"")
-              end
-            when :key_normal then
-              case char
-              when '=' then state = :value
-              when 'a'..'z', 'A'..'Z', '0'..'9', '-', ' ' then key << char
-              else raise(MalformedDnError, "Unrecognized RDN attribute type name character \"#{char}\"")
-              end
-            when :key_oid then
-              case char
-              when '=' then state = :value
-              when '0'..'9', '.', ' ' then key << char
-              else raise(MalformedDnError, "Unrecognized RDN OID attribute type name character \"#{char}\"")
-              end
-            when :value then
-              case char
-              when '\\' then state = :value_normal_escape
-              when '"' then state = :value_quoted
-              when ' ' then state = :value
-              when '#' then
-                state = :value_hexstring
-                value << char
-              when ',' then
-                state = :key
-                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
-                key = StringIO.new
-                value = StringIO.new
-              else
-                state = :value_normal
-                value << char
-              end
-            when :value_normal then
-              case char
-              when '\\' then state = :value_normal_escape
-              when ',' then
-                state = :key
-                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
-                key = StringIO.new
-                value = StringIO.new
-              when '+' then raise(UnsupportedDnFormatError, "Multivalued RDNs are not supported")
-              else value << char
-              end
-            when :value_normal_escape then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_normal_escape_hex
-                hex_buffer = char
-              else
-                state = :value_normal
-                value << char
-              end
-            when :value_normal_escape_hex then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_normal
-                value << "#{hex_buffer}#{char}".to_i(16).chr
-              else raise(MalformedDnError, "Invalid escaped hex code \"\\#{hex_buffer}#{char}\"")
-              end
-            when :value_quoted then
-              case char
-              when '\\' then state = :value_quoted_escape
-              when '"' then state = :value_end
-              else value << char
-              end
-            when :value_quoted_escape then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_quoted_escape_hex
-                hex_buffer = char
-              else
-                state = :value_quoted
-                value << char
-              end
-            when :value_quoted_escape_hex then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_quoted
-                value << "#{hex_buffer}#{char}".to_i(16).chr
-              else raise(MalformedDnError, "Expected the second character of a hex pair inside a double quoted value, but got \"#{char}\"")
-              end
-            when :value_hexstring then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_hexstring_hex
-                value << char
-              when ' ' then state = :value_end
-              when ',' then
-                state = :key
-                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
-                key = StringIO.new
-                value = StringIO.new
-              else raise(MalformedDnError, "Expected the first character of a hex pair, but got \"#{char}\"")
-              end
-            when :value_hexstring_hex then
-              case char
-              when '0'..'9', 'a'..'f', 'A'..'F' then
-                state = :value_hexstring
-                value << char
-              else raise(MalformedDnError, "Expected the second character of a hex pair, but got \"#{char}\"")
-              end
-            when :value_end then
-              case char
-              when ' ' then state = :value_end
-              when ',' then
-                state = :key
-                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
-                key = StringIO.new
-                value = StringIO.new
-              else raise(MalformedDnError, "Expected the end of an attribute value, but got \"#{char}\"")
-              end
-            else raise "Fell out of state machine"
-            end
-          end
-
-          # Last pair
-          raise(MalformedDnError, 'DN string ended unexpectedly') unless
-            [:value, :value_normal, :value_hexstring, :value_end].include? state
-
-          yield key.string.strip, rstrip_except_escaped(value.string, @dn.length)
-        end
-
-        def rstrip_except_escaped(str, dn_index)
-          str_ends_with_whitespace = str.match(/\s\z/)
+  disable_ddl_transaction!
 
-          if str_ends_with_whitespace
-            dn_part_ends_with_escaped_whitespace = @dn[0, dn_index].match(/\\(\s+)\z/)
-
-            if dn_part_ends_with_escaped_whitespace
-              dn_part_rwhitespace = dn_part_ends_with_escaped_whitespace[1]
-              num_chars_to_remove = dn_part_rwhitespace.length - 1
-              str = str[0, str.length - num_chars_to_remove]
-            else
-              str.rstrip!
-            end
-          end
-
-          str
-        end
-
-        ##
-        # Returns the DN as an array in the form expected by the constructor.
-        def to_a
-          a = []
-          self.each_pair { |key, value| a << key << value } unless @dn.empty?
-          a
-        end
-
-        ##
-        # Return the DN as an escaped string.
-        def to_s
-          @dn
-        end
-
-        ##
-        # Return the DN as an escaped and normalized string.
-        def to_normalized_s
-          self.class.new(*to_a).to_s.downcase
-        end
-
-        # https://tools.ietf.org/html/rfc4514 section 2.4 lists these exceptions
-        # for DN values. All of the following must be escaped in any normal string
-        # using a single backslash ('\') as escape. The space character is left
-        # out here because in a "normalized" string, spaces should only be escaped
-        # if necessary (i.e. leading or trailing space).
-        NORMAL_ESCAPES = [',', '+', '"', '\\', '<', '>', ';', '='].freeze
-
-        # The following must be represented as escaped hex
-        HEX_ESCAPES = {
-          "\n" => '\0a',
-          "\r" => '\0d'
-        }.freeze
-
-        # Compiled character class regexp using the keys from the above hash, and
-        # checking for a space or # at the start, or space at the end, of the
-        # string.
-        ESCAPE_RE = Regexp.new("(^ |^#| $|[" +
-                               NORMAL_ESCAPES.map { |e| Regexp.escape(e) }.join +
-                               "])")
-
-        HEX_ESCAPE_RE = Regexp.new("([" +
-                               HEX_ESCAPES.keys.map { |e| Regexp.escape(e) }.join +
-                               "])")
-
-        ##
-        # Escape a string for use in a DN value
-        def self.escape(string)
-          escaped = string.gsub(ESCAPE_RE) { |char| "\\" + char }
-          escaped.gsub(HEX_ESCAPE_RE) { |char| HEX_ESCAPES[char] }
-        end
+  class Identity < ActiveRecord::Base
+    include EachBatch
 
-        ##
-        # Proxy all other requests to the string object, because a DN is mainly
-        # used within the library as a string
-        # rubocop:disable GitlabSecurity/PublicSend
-        def method_missing(method, *args, &block)
-          @dn.send(method, *args, &block)
-        end
-      end
-    end
+    self.table_name = 'identities'
   end
 
   def up
     ldap_identities = Identity.where("provider like 'ldap%'")
-    ldap_identities.find_each do |identity|
-      begin
-        identity.extern_uid = Gitlab::LDAP::DN.new(identity.extern_uid).to_normalized_s
-        unless identity.save
-          say "Unable to normalize \"#{identity.extern_uid}\". Skipping."
-        end
-      rescue Gitlab::LDAP::MalformedDnError, Gitlab::LDAP::UnsupportedDnFormatError => e
-        say "Unable to normalize \"#{identity.extern_uid}\" due to \"#{e.message}\". Skipping."
-      end
+
+    if ldap_identities.any?
+      queue_background_migration_jobs_by_range_at_intervals(Identity, MIGRATION, DELAY_INTERVAL)
     end
   end
 
diff --git a/lib/gitlab/background_migration/normalize_ldap_extern_uids_range.rb b/lib/gitlab/background_migration/normalize_ldap_extern_uids_range.rb
new file mode 100644
index 00000000000..7a18feb8a4f
--- /dev/null
+++ b/lib/gitlab/background_migration/normalize_ldap_extern_uids_range.rb
@@ -0,0 +1,304 @@
+module Gitlab
+  module BackgroundMigration
+    class NormalizeLdapExternUidsRange
+      class Identity < ActiveRecord::Base
+        self.table_name = 'identities'
+      end
+
+      # Copied this class to make this migration resilient to future code changes.
+      # And if the normalize behavior is changed in the future, it must be
+      # accompanied by another migration.
+      module Gitlab
+        module LDAP
+          MalformedDnError = Class.new(StandardError)
+          UnsupportedDnFormatError = Class.new(StandardError)
+
+          class DN
+            def self.normalize_value(given_value)
+              dummy_dn = "placeholder=#{given_value}"
+              normalized_dn = new(*dummy_dn).to_normalized_s
+              normalized_dn.sub(/\Aplaceholder=/, '')
+            end
+
+            ##
+            # Initialize a DN, escaping as required. Pass in attributes in name/value
+            # pairs. If there is a left over argument, it will be appended to the dn
+            # without escaping (useful for a base string).
+            #
+            # Most uses of this class will be to escape a DN, rather than to parse it,
+            # so storing the dn as an escaped String and parsing parts as required
+            # with a state machine seems sensible.
+            def initialize(*args)
+              if args.length > 1
+                initialize_array(args)
+              else
+                initialize_string(args[0])
+              end
+            end
+
+            def initialize_array(args)
+              buffer = StringIO.new
+
+              args.each_with_index do |arg, index|
+                if index.even? # key
+                  buffer << "," if index > 0
+                  buffer << arg
+                else # value
+                  buffer << "="
+                  buffer << self.class.escape(arg)
+                end
+              end
+
+              @dn = buffer.string
+            end
+
+            def initialize_string(arg)
+              @dn = arg.to_s
+            end
+
+            ##
+            # Parse a DN into key value pairs using ASN from
+            # http://tools.ietf.org/html/rfc2253 section 3.
+            # rubocop:disable Metrics/AbcSize
+            # rubocop:disable Metrics/CyclomaticComplexity
+            # rubocop:disable Metrics/PerceivedComplexity
+            def each_pair
+              state = :key
+              key = StringIO.new
+              value = StringIO.new
+              hex_buffer = ""
+
+              @dn.each_char.with_index do |char, dn_index|
+                case state
+                when :key then
+                  case char
+                  when 'a'..'z', 'A'..'Z' then
+                    state = :key_normal
+                    key << char
+                  when '0'..'9' then
+                    state = :key_oid
+                    key << char
+                  when ' ' then state = :key
+                  else raise(MalformedDnError, "Unrecognized first character of an RDN attribute type name \"#{char}\"")
+                  end
+                when :key_normal then
+                  case char
+                  when '=' then state = :value
+                  when 'a'..'z', 'A'..'Z', '0'..'9', '-', ' ' then key << char
+                  else raise(MalformedDnError, "Unrecognized RDN attribute type name character \"#{char}\"")
+                  end
+                when :key_oid then
+                  case char
+                  when '=' then state = :value
+                  when '0'..'9', '.', ' ' then key << char
+                  else raise(MalformedDnError, "Unrecognized RDN OID attribute type name character \"#{char}\"")
+                  end
+                when :value then
+                  case char
+                  when '\\' then state = :value_normal_escape
+                  when '"' then state = :value_quoted
+                  when ' ' then state = :value
+                  when '#' then
+                    state = :value_hexstring
+                    value << char
+                  when ',' then
+                    state = :key
+                    yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
+                    key = StringIO.new
+                    value = StringIO.new
+                  else
+                    state = :value_normal
+                    value << char
+                  end
+                when :value_normal then
+                  case char
+                  when '\\' then state = :value_normal_escape
+                  when ',' then
+                    state = :key
+                    yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
+                    key = StringIO.new
+                    value = StringIO.new
+                  when '+' then raise(UnsupportedDnFormatError, "Multivalued RDNs are not supported")
+                  else value << char
+                  end
+                when :value_normal_escape then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_normal_escape_hex
+                    hex_buffer = char
+                  else
+                    state = :value_normal
+                    value << char
+                  end
+                when :value_normal_escape_hex then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_normal
+                    value << "#{hex_buffer}#{char}".to_i(16).chr
+                  else raise(MalformedDnError, "Invalid escaped hex code \"\\#{hex_buffer}#{char}\"")
+                  end
+                when :value_quoted then
+                  case char
+                  when '\\' then state = :value_quoted_escape
+                  when '"' then state = :value_end
+                  else value << char
+                  end
+                when :value_quoted_escape then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_quoted_escape_hex
+                    hex_buffer = char
+                  else
+                    state = :value_quoted
+                    value << char
+                  end
+                when :value_quoted_escape_hex then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_quoted
+                    value << "#{hex_buffer}#{char}".to_i(16).chr
+                  else raise(MalformedDnError, "Expected the second character of a hex pair inside a double quoted value, but got \"#{char}\"")
+                  end
+                when :value_hexstring then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_hexstring_hex
+                    value << char
+                  when ' ' then state = :value_end
+                  when ',' then
+                    state = :key
+                    yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
+                    key = StringIO.new
+                    value = StringIO.new
+                  else raise(MalformedDnError, "Expected the first character of a hex pair, but got \"#{char}\"")
+                  end
+                when :value_hexstring_hex then
+                  case char
+                  when '0'..'9', 'a'..'f', 'A'..'F' then
+                    state = :value_hexstring
+                    value << char
+                  else raise(MalformedDnError, "Expected the second character of a hex pair, but got \"#{char}\"")
+                  end
+                when :value_end then
+                  case char
+                  when ' ' then state = :value_end
+                  when ',' then
+                    state = :key
+                    yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
+                    key = StringIO.new
+                    value = StringIO.new
+                  else raise(MalformedDnError, "Expected the end of an attribute value, but got \"#{char}\"")
+                  end
+                else raise "Fell out of state machine"
+                end
+              end
+
+              # Last pair
+              raise(MalformedDnError, 'DN string ended unexpectedly') unless
+                [:value, :value_normal, :value_hexstring, :value_end].include? state
+
+              yield key.string.strip, rstrip_except_escaped(value.string, @dn.length)
+            end
+
+            def rstrip_except_escaped(str, dn_index)
+              str_ends_with_whitespace = str.match(/\s\z/)
+
+              if str_ends_with_whitespace
+                dn_part_ends_with_escaped_whitespace = @dn[0, dn_index].match(/\\(\s+)\z/)
+
+                if dn_part_ends_with_escaped_whitespace
+                  dn_part_rwhitespace = dn_part_ends_with_escaped_whitespace[1]
+                  num_chars_to_remove = dn_part_rwhitespace.length - 1
+                  str = str[0, str.length - num_chars_to_remove]
+                else
+                  str.rstrip!
+                end
+              end
+
+              str
+            end
+
+            ##
+            # Returns the DN as an array in the form expected by the constructor.
+            def to_a
+              a = []
+              self.each_pair { |key, value| a << key << value } unless @dn.empty?
+              a
+            end
+
+            ##
+            # Return the DN as an escaped string.
+            def to_s
+              @dn
+            end
+
+            ##
+            # Return the DN as an escaped and normalized string.
+            def to_normalized_s
+              self.class.new(*to_a).to_s.downcase
+            end
+
+            # https://tools.ietf.org/html/rfc4514 section 2.4 lists these exceptions
+            # for DN values. All of the following must be escaped in any normal string
+            # using a single backslash ('\') as escape. The space character is left
+            # out here because in a "normalized" string, spaces should only be escaped
+            # if necessary (i.e. leading or trailing space).
+            NORMAL_ESCAPES = [',', '+', '"', '\\', '<', '>', ';', '='].freeze
+
+            # The following must be represented as escaped hex
+            HEX_ESCAPES = {
+              "\n" => '\0a',
+              "\r" => '\0d'
+            }.freeze
+
+            # Compiled character class regexp using the keys from the above hash, and
+            # checking for a space or # at the start, or space at the end, of the
+            # string.
+            ESCAPE_RE = Regexp.new("(^ |^#| $|[" +
+                                   NORMAL_ESCAPES.map { |e| Regexp.escape(e) }.join +
+                                   "])")
+
+            HEX_ESCAPE_RE = Regexp.new("([" +
+                                   HEX_ESCAPES.keys.map { |e| Regexp.escape(e) }.join +
+                                   "])")
+
+            ##
+            # Escape a string for use in a DN value
+            def self.escape(string)
+              escaped = string.gsub(ESCAPE_RE) { |char| "\\" + char }
+              escaped.gsub(HEX_ESCAPE_RE) { |char| HEX_ESCAPES[char] }
+            end
+
+            ##
+            # Proxy all other requests to the string object, because a DN is mainly
+            # used within the library as a string
+            # rubocop:disable GitlabSecurity/PublicSend
+            def method_missing(method, *args, &block)
+              @dn.send(method, *args, &block)
+            end
+          end
+        end
+      end
+
+      def perform(start_id, end_id)
+        return unless migrate?
+
+        ldap_identities = Identity.where("provider like 'ldap%'").where(id: start_id..end_id)
+        ldap_identities.each do |identity|
+          begin
+            identity.extern_uid = Gitlab::LDAP::DN.new(identity.extern_uid).to_normalized_s
+            unless identity.save
+              Rails.logger.info "Unable to normalize \"#{identity.extern_uid}\". Skipping."
+            end
+          rescue Gitlab::LDAP::MalformedDnError, Gitlab::LDAP::UnsupportedDnFormatError => e
+            Rails.logger.info "Unable to normalize \"#{identity.extern_uid}\" due to \"#{e.message}\". Skipping."
+          end
+        end
+      end
+
+      def migrate?
+        Identity.table_exists?
+      end
+    end
+  end
+end