Increase text limit for GPG keys (mysql only).

Closes #46530.

changelogs/unreleased/ab-46530-mediumtext-for-gpg-keys.yml

+---
+title: Increase text limit for GPG keys (mysql only).
+merge_request: 19069
+author:
+type: other

db/migrate/20180521171529_increase_mysql_text_limit_for_gpg_keys.rb

+# rubocop:disable all
+require_relative 'gpg_keys_limits_to_mysql'

db/migrate/gpg_keys_limits_to_mysql.rb

+class IncreaseMysqlTextLimitForGpgKeys < ActiveRecord::Migration
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  def up
+    return unless Gitlab::Database.mysql?
+
+    change_column :gpg_keys, :key, :text, limit: 16.megabytes - 1
+  end
+
+  def down
+    # no-op
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180517082340) do
+ActiveRecord::Schema.define(version: 20180521171529) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"

lib/tasks/migrate/add_limits_mysql.rake

@@ -2,6 +2,7 @@ require Rails.root.join('db/migrate/limits_to_mysql')
 require Rails.root.join('db/migrate/markdown_cache_limits_to_mysql')
 require Rails.root.join('db/migrate/merge_request_diff_file_limits_to_mysql')
 require Rails.root.join('db/migrate/limits_ci_build_trace_chunks_raw_data_for_mysql')
+require Rails.root.join('db/migrate/gpg_keys_limits_to_mysql')
 
 desc "GitLab | Add limits to strings in mysql database"
 task add_limits_mysql: :environment do
@@ -10,4 +11,5 @@ task add_limits_mysql: :environment do
   MarkdownCacheLimitsToMysql.new.up
   MergeRequestDiffFileLimitsToMysql.new.up
   LimitsCiBuildTraceChunksRawDataForMysql.new.up
+  IncreaseMysqlTextLimitForGpgKeys.new.up
 end