1 files changed, 31 insertions, 0 deletions
diff --git a/config/initializers/validate_database_config.rb b/config/initializers/validate_database_config.rb
new file mode 100644
index 00000000000..a651db8b783
--- /dev/null
+++ b/config/initializers/validate_database_config.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+if Gitlab::Utils.to_boolean(ENV['SKIP_DATABASE_CONFIG_VALIDATION'], default: false)
+  return
+end
+
+if Rails.application.config.uses_legacy_database_config
+  warn "WARNING: This installation of GitLab uses a deprecated syntax for 'config/database.yml'. " \
+    "The support for this syntax will be removed in 15.0. " \
+    "More information can be found here: https://gitlab.com/gitlab-org/gitlab/-/issues/338182"
+end
+
+if configurations = ActiveRecord::Base.configurations.configurations
+  if configurations.first.name != Gitlab::Database::MAIN_DATABASE_NAME
+    raise "ERROR: This installation of GitLab uses unsupported 'config/database.yml'. " \
+      "The `main:` database needs to be defined as a first configuration item instead of `#{configurations.first.name}`."
+  end
+
+  rejected_config_names = configurations.map(&:name).to_set - Gitlab::Database::DATABASE_NAMES
+  if rejected_config_names.any?
+    raise "ERROR: This installation of GitLab uses unsupported database names " \
+      "in 'config/database.yml': #{rejected_config_names.to_a.join(", ")}. The only supported ones are " \
+      "#{Gitlab::Database::DATABASE_NAMES.join(", ")}."
+  end
+
+  replicas_config_names = configurations.select(&:replica?).map(&:name)
+  if replicas_config_names.any?
+    raise "ERROR: This installation of GitLab uses unsupported database configuration " \
+      "with 'replica: true' parameter in 'config/database.yml' for: #{replicas_config_names.join(", ")}"
+  end
+end