Updated cluster token name migration

Renamed migrations since master now has a conflicting migration
Added missing db/schema_migrations/20210303165302

changelogs/unreleased/322745-add-missing-token-names.yml

+---
+title: Update cluster agent tokens with null names
+merge_request: 55673
+author:
+type: changed

db/migrate/20210303165301_add_not_null_constraint_to_cluster_token_name.rb

+# frozen_string_literal: true
+
+class AddNotNullConstraintToClusterTokenName < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    # This will add the `NOT NULL` constraint WITHOUT validating it
+    add_not_null_constraint :cluster_agent_tokens, :name, validate: false
+  end
+
+  def down
+    remove_not_null_constraint :cluster_agent_tokens, :name
+  end
+end

db/post_migrate/20210303165302_cleanup_cluster_tokens_with_null_name.rb

+# frozen_string_literal: true
+
+class CleanupClusterTokensWithNullName < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  BATCH_SIZE = 1000
+
+  disable_ddl_transaction!
+
+  class AgentToken < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'cluster_agent_tokens'
+  end
+
+  def up
+    AgentToken.each_batch(of: BATCH_SIZE) do |relation|
+      relation.where('name IS NULL').update_all("name = 'agent-token-' || id")
+    end
+  end
+
+  def down
+    # no-op : can't go back to `NULL` without first dropping the `NOT NULL` constraint
+  end
+end

db/schema_migrations/20210303165301

+fa82a0f6c57a527a143da56ae0d70245a7d711b5e5ff3eb959fd6b2cf5872dac
\ No newline at end of file

db/schema_migrations/20210303165302

+1cb74abdc7134c3252425c3ceb8cd9dc4b157d64b1a2ff7928153e78b05d9121
\ No newline at end of file

db/structure.sql

@@ -19952,6 +19952,9 @@ ALTER TABLE ONLY chat_names
 ALTER TABLE ONLY chat_teams
     ADD CONSTRAINT chat_teams_pkey PRIMARY KEY (id);
 
+ALTER TABLE cluster_agent_tokens
+    ADD CONSTRAINT check_0fb634d04d CHECK ((name IS NOT NULL)) NOT VALID;
+
 ALTER TABLE vulnerability_scanners
     ADD CONSTRAINT check_37608c9db5 CHECK ((char_length(vendor) <= 255)) NOT VALID;