engine/schema: fix missing 4.20.1.0 node in DB upgrade hierarchy

Direct upgrade from 4.20.1.0 to 4.20.3.0 failed because the upgrade
hierarchy skipped the 4.20.1.0 node, causing DatabaseVersionHierarchy
to fall back to 4.20.0.0 and re-run Upgrade42000to42010. This triggered
a duplicate key violation on configuration_group.name='Usage Server'
which already existed from the original 4.20.1.0 install.

- Add Upgrade42010to42020 no-op upgrader to register 4.20.1.0 in the
  upgrade hierarchy
- Register it in DatabaseUpgradeChecker between 4.20.0.0 and 4.20.2.0
- Harden schema-42000to42010.sql with INSERT IGNORE as a safety net
- Add unit tests for direct 4.20.1.0->4.20.3.0 and 4.20.2.0->4.20.3.0
  upgrade paths

Author: RosiKyu

engine/schema/src/main/java/com/cloud/upgrade/DatabaseUpgradeChecker.java

@@ -33,6 +33,7 @@
 
 import javax.inject.Inject;
 
+import com.cloud.upgrade.dao.Upgrade42010to42020;
 import com.cloud.upgrade.dao.Upgrade42020to42030;
 import com.cloud.utils.FileUtil;
 import org.apache.cloudstack.utils.CloudStackVersion;
@@ -237,6 +238,7 @@ public DatabaseUpgradeChecker() {
                 .next("4.19.0.0", new Upgrade41900to41910())
                 .next("4.19.1.0", new Upgrade41910to42000())
                 .next("4.20.0.0", new Upgrade42000to42010())
+                .next("4.20.1.0", new Upgrade42010to42020())
                 .next("4.20.2.0", new Upgrade42020to42030())
                 .build();
     }

engine/schema/src/main/java/com/cloud/upgrade/dao/Upgrade42010to42020.java

@@ -0,0 +1,64 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+package com.cloud.upgrade.dao;
+
+import java.io.InputStream;
+import java.sql.Connection;
+
+import com.cloud.utils.exception.CloudRuntimeException;
+
+public class Upgrade42010to42020 extends DbUpgradeAbstractImpl implements DbUpgrade {
+
+    @Override
+    public String[] getUpgradableVersionRange() {
+        return new String[]{"4.20.1.0", "4.20.2.0"};
+    }
+
+    @Override
+    public String getUpgradedVersion() {
+        return "4.20.2.0";
+    }
+
+    @Override
+    public boolean supportsRollingUpgrade() {
+        return false;
+    }
+
+    @Override
+    public InputStream[] getPrepareScripts() {
+        final String scriptFile = "META-INF/db/schema-42010to42020.sql";
+        final InputStream script = Thread.currentThread().getContextClassLoader().getResourceAsStream(scriptFile);
+        if (script == null) {
+            throw new CloudRuntimeException("Unable to find " + scriptFile);
+        }
+        return new InputStream[]{script};
+    }
+
+    @Override
+    public void performDataMigration(Connection conn) {
+    }
+
+    @Override
+    public InputStream[] getCleanupScripts() {
+        final String scriptFile = "META-INF/db/schema-42010to42020-cleanup.sql";
+        final InputStream script = Thread.currentThread().getContextClassLoader().getResourceAsStream(scriptFile);
+        if (script == null) {
+            throw new CloudRuntimeException("Unable to find " + scriptFile);
+        }
+        return new InputStream[]{script};
+    }
+}

engine/schema/src/main/resources/META-INF/db/schema-42000to42010.sql

@@ -31,7 +31,7 @@ CALL `cloud`.`IDEMPOTENT_ADD_COLUMN`('cloud.account', 'api_key_access', 'boolean
 CALL `cloud_usage`.`IDEMPOTENT_ADD_COLUMN`('cloud_usage.account', 'api_key_access', 'boolean DEFAULT NULL COMMENT "is api key access allowed for the account" ');
 
 -- Create a new group for Usage Server related configurations
-INSERT INTO `cloud`.`configuration_group` (`name`, `description`, `precedence`) VALUES ('Usage Server', 'Usage Server related configuration', 9);
+INSERT IGNORE INTO `cloud`.`configuration_group` (`name`, `description`, `precedence`) VALUES ('Usage Server', 'Usage Server related configuration', 9);
 UPDATE `cloud`.`configuration_subgroup` set `group_id` = (SELECT `id` FROM `cloud`.`configuration_group` WHERE `name` = 'Usage Server'), `precedence` = 1 WHERE `name`='Usage';
 UPDATE `cloud`.`configuration` SET `group_id` = (SELECT `id` FROM `cloud`.`configuration_group` WHERE `name` = 'Usage Server') where `subgroup_id` = (SELECT `id` FROM `cloud`.`configuration_subgroup` WHERE `name` = 'Usage');
 

engine/schema/src/main/resources/META-INF/db/schema-42010to42020-cleanup.sql

@@ -0,0 +1,20 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+--;
+-- Schema upgrade cleanup from 4.20.1.0 to 4.20.2.0
+--;

engine/schema/src/main/resources/META-INF/db/schema-42010to42020.sql

@@ -0,0 +1,20 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+--;
+-- Schema upgrade from 4.20.1.0 to 4.20.2.0
+--;

engine/schema/src/test/java/com/cloud/upgrade/DatabaseUpgradeCheckerTest.java

@@ -51,6 +51,8 @@
 import com.cloud.upgrade.dao.Upgrade470to471;
 import com.cloud.upgrade.dao.Upgrade471to480;
 import com.cloud.upgrade.dao.Upgrade480to481;
+import com.cloud.upgrade.dao.Upgrade42010to42020;
+import com.cloud.upgrade.dao.Upgrade42020to42030;
 import com.cloud.upgrade.dao.Upgrade490to4910;
 
 import com.cloud.utils.db.TransactionLegacy;
@@ -360,6 +362,42 @@ public void testCalculateUpgradePathFromSecurityReleaseToNextSecurityRelease() {
         assertTrue(upgradesFromSecurityReleaseToNext[upgradesFromSecurityReleaseToNext.length - 1] instanceof NoopDbUpgrade);
     }
 
+    @Test
+    public void testCalculateUpgradePath42010to42030() {
+        // Regression test for: missing 4.20.1.0 node in upgrade hierarchy
+        // caused direct 4.20.1.0 -> 4.20.3.0 upgrade to re-run Upgrade42000to42010
+        // and fail with duplicate key on configuration_group.name='Usage Server'
+        final CloudStackVersion dbVersion = CloudStackVersion.parse("4.20.1.0");
+        assertNotNull(dbVersion);
+
+        final CloudStackVersion currentVersion = CloudStackVersion.parse("4.20.3.0");
+        assertNotNull(currentVersion);
+
+        final DatabaseUpgradeChecker checker = new DatabaseUpgradeChecker();
+        final DbUpgrade[] upgrades = checker.calculateUpgradePath(dbVersion, currentVersion);
+
+        assertNotNull(upgrades);
+        assertEquals("Direct upgrade from 4.20.1.0 to 4.20.3.0 should have exactly 2 steps", 2, upgrades.length);
+        assertTrue("First step should be Upgrade42010to42020", upgrades[0] instanceof Upgrade42010to42020);
+        assertTrue("Second step should be Upgrade42020to42030", upgrades[1] instanceof Upgrade42020to42030);
+    }
+
+    @Test
+    public void testCalculateUpgradePath42020to42030() {
+        final CloudStackVersion dbVersion = CloudStackVersion.parse("4.20.2.0");
+        assertNotNull(dbVersion);
+
+        final CloudStackVersion currentVersion = CloudStackVersion.parse("4.20.3.0");
+        assertNotNull(currentVersion);
+
+        final DatabaseUpgradeChecker checker = new DatabaseUpgradeChecker();
+        final DbUpgrade[] upgrades = checker.calculateUpgradePath(dbVersion, currentVersion);
+
+        assertNotNull(upgrades);
+        assertEquals("Upgrade from 4.20.2.0 to 4.20.3.0 should have exactly 1 step", 1, upgrades.length);
+        assertTrue("Only step should be Upgrade42020to42030", upgrades[0] instanceof Upgrade42020to42030);
+    }
+
     @Test
     public void isStandalone() throws SQLException {
         // simulate zero 'UP' hosts -> standalone