Icinga#2885 Fix MySQL8.4 nonstandard foreign keys deprecation

If you try to set up icinga director with the latest minor version of MySQL 8.4+, the schema creation will fail with confusing SQL error messages. This commit aims to fix that. https://dev.mysql.com/doc/refman/8.4/en/mysql-nutshell.html#mysql-nutshell-deprecations

schema/mysql-migrations/upgrade_188.sql

@@ -0,0 +1,13 @@
+ALTER TABLE director_activity_log
+ADD UNIQUE INDEX idx_checksum (checksum);
+
+ALTER TABLE director_generated_config
+ADD CONSTRAINT fk_director_generated_config_activity
+    FOREIGN KEY (last_activity_checksum)
+    REFERENCES director_activity_log(checksum)
+    ON DELETE RESTRICT
+    ON UPDATE RESTRICT;
+
+INSERT INTO director_schema_migration
+  (schema_version, migration_time)
+  VALUES (188, NOW());

schema/mysql.sql

@@ -46,7 +46,8 @@ CREATE TABLE director_activity_log (
   INDEX search_idx (object_name),
   INDEX search_idx2 (object_type(32), object_name(64), change_time),
   INDEX search_author (author),
-  INDEX checksum (checksum)
+  INDEX checksum (checksum),
+  UNIQUE INDEX idx_checksum (checksum)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
 CREATE TABLE director_activity_log_remark (
@@ -113,9 +114,10 @@ CREATE TABLE director_generated_config (
   first_activity_checksum VARBINARY(20) NOT NULL,
   last_activity_checksum VARBINARY(20) NOT NULL,
   PRIMARY KEY (checksum),
-  CONSTRAINT director_generated_config_activity
-    FOREIGN KEY activity_checksum (last_activity_checksum)
-    REFERENCES director_activity_log (checksum)
+  INDEX idx_checksum (checksum),
+  CONSTRAINT fk_director_generated_config_activity
+    FOREIGN KEY (last_activity_checksum)
+    REFERENCES director_activity_log(checksum)
     ON DELETE RESTRICT
     ON UPDATE RESTRICT
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
@@ -2446,4 +2448,4 @@ CREATE TABLE branched_icinga_dependency (
 
 INSERT INTO director_schema_migration
   (schema_version, migration_time)
-  VALUES (187, NOW());
+  VALUES (188, NOW());