1 files changed, 40 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/backfill_environment_tiers.rb b/lib/gitlab/background_migration/backfill_environment_tiers.rb
new file mode 100644
index 00000000000..6f381577274
--- /dev/null
+++ b/lib/gitlab/background_migration/backfill_environment_tiers.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # This class backfills the `environments.tier` column by using `guess_tier` logic.
+    # Environments created after 13.10 already have a value, however, environments created before 13.10 don't.
+    # See https://gitlab.com/gitlab-org/gitlab/-/issues/300741 for more information.
+    class BackfillEnvironmentTiers < BatchedMigrationJob
+      operation_name :backfill_environment_tiers
+
+      # Equivalent to `Environment#guess_tier` pattern matching.
+      PRODUCTION_TIER = 0
+      STAGING_TIER = 1
+      TESTING_TIER = 2
+      DEVELOPMENT_TIER = 3
+      OTHER_TIER = 4
+
+      TIER_REGEXP_PAIR = [
+        { tier: DEVELOPMENT_TIER, regexp: '(dev|review|trunk)' },
+        { tier: TESTING_TIER, regexp: '(test|tst|int|ac(ce|)pt|qa|qc|control|quality)' },
+        { tier: STAGING_TIER, regexp: '(st(a|)g|mod(e|)l|pre|demo|non)' },
+        { tier: PRODUCTION_TIER, regexp: '(pr(o|)d|live)' }
+      ].freeze
+
+      def perform
+        TIER_REGEXP_PAIR.each do |pair|
+          each_sub_batch(
+            batching_scope: ->(relation) { relation.where(tier: nil).where("name ~* '#{pair[:regexp]}'") } # rubocop:disable GitlabSecurity/SqlInjection
+          ) do |sub_batch|
+            sub_batch.update_all(tier: pair[:tier])
+          end
+        end
+
+        each_sub_batch(batching_scope: ->(relation) { relation.where(tier: nil) }) do |sub_batch|
+          sub_batch.update_all(tier: OTHER_TIER)
+        end
+      end
+    end
+  end
+end