feat(sql): Support multiple root liquibase changesets (spinnaker#2421)

orca-sql/src/main/kotlin/com/netflix/spinnaker/config/SqlConfiguration.kt

@@ -19,6 +19,7 @@ import com.fasterxml.jackson.databind.ObjectMapper
 import com.netflix.spectator.api.Registry
 import com.netflix.spinnaker.orca.sql.JooqSqlCommentAppender
 import com.netflix.spinnaker.orca.sql.JooqToSpringExceptionTransformer
+import com.netflix.spinnaker.orca.sql.SpringLiquibaseProxy
 import com.netflix.spinnaker.orca.sql.SqlHealthIndicator
 import com.netflix.spinnaker.orca.sql.SqlHealthcheckActivator
 import com.netflix.spinnaker.orca.sql.config.DataSourceConfiguration
@@ -39,7 +40,6 @@ import org.springframework.context.annotation.ComponentScan
 import org.springframework.context.annotation.Configuration
 import org.springframework.context.annotation.Import
 import org.springframework.jdbc.datasource.DataSourceTransactionManager
-import org.springframework.jdbc.datasource.SingleConnectionDataSource
 import org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy
 import sun.net.InetAddressCachePolicy
 import java.lang.reflect.Field
@@ -63,20 +63,7 @@ class SqlConfiguration {
   }
 
   @Bean fun liquibase(properties: SqlProperties): SpringLiquibase =
-    properties.migration
-      .run {
-        val ds = SingleConnectionDataSource(jdbcUrl, user, password, false)
-        if (driver != null) {
-          ds.setDriverClassName(driver)
-        }
-        ds
-      }
-      .let { ds ->
-        SpringLiquibase().apply {
-          changeLog = "classpath:db/changelog-master.yml"
-          dataSource = ds
-        }
-      }
+    SpringLiquibaseProxy(properties)
 
   @Bean fun transactionManager(dataSource: DataSource): DataSourceTransactionManager =
     DataSourceTransactionManager(dataSource)

orca-sql/src/main/kotlin/com/netflix/spinnaker/config/SqlProperties.kt

@@ -32,7 +32,8 @@ data class MigrationProperties(
   var jdbcUrl: String = "jdbc:mysql://localhost/orca",
   var user: String? = null,
   var password: String? = null,
-  var driver: String? = null
+  var driver: String? = null,
+  var additionalChangeLogs: List<String> = listOf()
 )
 
 data class ConnectionPoolProperties(

orca-sql/src/main/kotlin/com/netflix/spinnaker/orca/sql/SpringLiquibaseProxy.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2018 Netflix, Inc.
+ *
+ * Licensed 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.netflix.spinnaker.orca.sql
+
+import com.netflix.spinnaker.config.SqlProperties
+import liquibase.integration.spring.SpringLiquibase
+import org.springframework.jdbc.datasource.SingleConnectionDataSource
+import javax.sql.DataSource
+
+/**
+ * Proxies Spring's Liquibase bean to allow multiple, independent Liquibase
+ * changesets to be used within a single Orca application.
+ *
+ * The use case behind this is to allow private extensions to make additional
+ * database schema changes atop OSS.
+ *
+ * IMPORTANT: While using this, ensure that you do not make any changes to any
+ * OSS schemas, and namespace tables that you've created so not to collide with
+ * potential future Orca changes. Spinnaker's OSS schema cannot and will not
+ * make considerations for custom integrations layered atop its schema.
+ */
+class SpringLiquibaseProxy(
+  private val sqlProperties: SqlProperties
+) : SpringLiquibase() {
+
+  init {
+    changeLog = "classpath:db/changelog-master.yml"
+    dataSource = createDataSource()
+  }
+
+  /**
+   * Everything has to be done in afterPropertiesSet, because that's how Spring
+   * expects things to be done for cleanup purposes, etc.
+   */
+  override fun afterPropertiesSet() {
+    // First do the OSS migrations
+    super.afterPropertiesSet()
+
+    // Then if anything else has been defined, do that afterwards
+    sqlProperties.migration.additionalChangeLogs
+      .map {
+        SpringLiquibase().apply {
+          changeLog = "classpath:$it"
+          dataSource = createDataSource()
+          resourceLoader = this@SpringLiquibaseProxy.resourceLoader
+        }
+      }
+      .forEach {
+        it.afterPropertiesSet()
+      }
+  }
+
+  private fun createDataSource(): DataSource =
+    sqlProperties.migration.run {
+      val ds = SingleConnectionDataSource(jdbcUrl, user, password, true)
+      if (driver != null) {
+        ds.setDriverClassName(driver)
+      }
+      ds
+    }
+}