如何为Spark Java提供动态数据库配置凭据？

我正在使用spark java构建一个简单的REST API。 该项目使用Postgres DB存储， gradle作为构建系统。 胖Jar部署在AWS 。

我有三个local环境， staging和production环境。 对于每个胖子创建，我想提供特定的配置，如下面用于本地构建的配置：

  dbHost = "localhost" dbUsername = "myusername" dbPassword = "mypassword" database = "mydb" dbPort = "5432" 

如何基于fatJar构建变体动态提供这些值？

Answer 1

我曾经使用.properties文件来跟随这个示例github项目Kotlin-dev-proxy 。

服务器读取名为app_environment的环境变量并使用适当的资源文件。

示例代码：

DbConfig.kt

 data class DbConfig( val dbHost: String, val dbUsername: String, val dbPassword: String, val dbName: String, val dbPort: Int) 

ServerSettings.kt

 class ServerSettings(settings: String) { val resources = Properties() init { val fileUrl: URL = resources.javaClass.getResource("/$settings.properties") ?: throw FileNotFoundException("$settings.properties file not found") fileUrl.openStream().use { resources.load(it) } } fun printSettings() = resources.stringPropertyNames().forEach { println("Property: $it has value: '${resources[it]}'") } fun getString(key: String): String = resources[key]!! as String fun getInt(key: String): Int = (resources[key]!! as String).toInt() } 

DbConfig.kt

 fun provideDbConfig(): DbConfig { val settings = ServerSettings(System.getenv("app_environment")) settings.printSettings() return DbConfig( dbHost = settings.getString("dbHost"), dbUsername = settings.getString("dbUsername"), dbPassword = settings.getString("dbPassword"), dbName = settings.getString("dbName"), dbPort = settings.getInt("dbPort") ) } 

资源/ develop.properties

 # Local Db values dbHost=localhost dbUsername=postgresusername dbPassword=postgrespassword dbName=mydbname dbPort=5432 

在Amazon EBS中部署时，转到软件配置并为环境添加适当的环境变量（分段/生产）。