Allow multiple repository storage shards to be enabled, and automatically round-robin between them

1 files changed, 35 insertions, 4 deletions

diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index c99aa7772bb..6e7a90e7d9c 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -18,6 +18,7 @@ class ApplicationSetting < ActiveRecord::Base
   serialize :disabled_oauth_sign_in_sources, Array
   serialize :domain_whitelist, Array
   serialize :domain_blacklist, Array
+  serialize :repository_storages
 
   cache_markdown_field :sign_in_text
   cache_markdown_field :help_page_text
@@ -74,9 +75,8 @@ class ApplicationSetting < ActiveRecord::Base
             presence: true,
             numericality: { only_integer: true, greater_than: 0 }
 
-  validates :repository_storage,
-    presence: true,
-    inclusion: { in: ->(_object) { Gitlab.config.repositories.storages.keys } }
+  validates :repository_storages, presence: true
+  validate :check_repository_storages
 
   validates :enabled_git_access_protocol,
             inclusion: { in: %w(ssh http), allow_blank: true, allow_nil: true }
@@ -166,7 +166,7 @@ class ApplicationSetting < ActiveRecord::Base
       disabled_oauth_sign_in_sources: [],
       send_user_confirmation_email: false,
       container_registry_token_expire_delay: 5,
-      repository_storage: 'default',
+      repository_storages: ['default'],
       user_default_external: false,
     )
   end
@@ -201,6 +201,29 @@ class ApplicationSetting < ActiveRecord::Base
     self.domain_blacklist_raw = file.read
   end
 
+  def repository_storages
+    value = read_attribute(:repository_storages)
+    value = [value] if value.is_a?(String)
+    value = [] if value.nil?
+
+    value
+  end
+
+  # repository_storage is still required in the API. Remove in 9.0
+  def repository_storage
+    repository_storages.first
+  end
+
+  def repository_storage=(value)
+    self.repository_storages = [value]
+  end
+
+  # Choose one of the available repository storage options. Currently all have
+  # equal weighting.
+  def pick_repository_storage
+    repository_storages.sample
+  end
+
   def runners_registration_token
     ensure_runners_registration_token!
   end
@@ -208,4 +231,12 @@ class ApplicationSetting < ActiveRecord::Base
   def health_check_access_token
     ensure_health_check_access_token!
   end
+
+  private
+
+  def check_repository_storages
+    invalid = repository_storages - Gitlab.config.repositories.storages.keys
+    errors.add(:repository_storages, "can't include: #{invalid.join(", ")}") unless
+      invalid.empty?
+  end
 end