amazon-web-services - RDS 环境变量对 AWS 上的 Elastic Beanstalk 实例不可用？

Question

使用 RDS 创建 Java 8 Elastic Beanstalk 实例后，RDS 连接详细信息作为环境变量不可见(它们在其他正在运行的实例上可见)。

运行后printenv命令，期望这些值可用，但它们不是。

RDS_HOSTNAME=foo.com

RDS_USERNAME=foo

RDS_PASS=bar

这些是服务器配置所必需的

database:
    driverClass: com.mysql.jdbc.Driver
    user: ${RDS_USERNAME}
    password: ${RDS_PASSWORD}
    url: jdbc:mysql://${RDS_HOSTNAME}/${RDS_DB_NAME}

在应用程序触发期间，它们不可用，日志显示 Java 异常，无法找到环境变量。

io.dropwizard.configuration.UndefinedEnvironmentVariableException: The environment variable 'RDS_USERNAME' is not defined; could not substitute the expression '${RDS_USERNAME}'. at io.dropwizard.configuration.EnvironmentVariableLookup.lookup(EnvironmentVariableLookup.java:41) at org.apache.commons.lang3.text.StrSubstitutor.resolveVariable(StrSubstitutor.java:934) at org.apache.commons.lang3.text.StrSubstitutor.substitute(StrSubstitutor.java:855) at org.apache.commons.lang3.text.StrSubstitutor.substitute(StrSubstitutor.java:743) at org.apache.commons.lang3.text.StrSubstitutor.replace(StrSubstitutor.java:403) at io.dropwizard.configuration.SubstitutingSourceProvider.open(SubstitutingSourceProvider.java:39) at io.dropwizard.configuration.BaseConfigurationFactory.build(BaseConfigurationFactory.java:83) at io.dropwizard.cli.ConfiguredCommand.parseConfiguration(ConfiguredCommand.java:124) at io.dropwizard.cli.ConfiguredCommand.run(ConfiguredCommand.java:72) at io.dropwizard.cli.Cli.run(Cli.java:75) at io.dropwizard.Application.run(Application.java:93)

但是，如果我在 ec2 实例上运行以下命令

sudo /opt/elasticbeanstalk/bin/get-config environment

它以 JSON 格式打印值:

{"CONFIG":"dev.yml","RDS_HOSTNAME":"foo.com","RDS_PASSWORD":"foo","M2":"/usr/local/apache-maven/bin","M2_HOME":"/usr/local/apache-maven","RDS_DB_NAME":"foo","JAVA_HOME":"/usr/lib/jvm/java","RDS_USERNAME":"foo","GRADLE_HOME":"/usr/local/gradle","RDS_PORT":"3306"}

任何想法如何为 ec2-user 恢复这些值？

我试过了:

重启EB实例

重建实例

cat将值放入脚本中，将它们设置在 eb deploy 之后

任何想法，为什么它们在这个特定实例上不可见？

实例详情

  Environment details foo: foo-service
  Application name: foo-service
  Region: eu-west-2
  Platform: arn:aws:elasticbeanstalk:eu-west-2::platform/Java 8 running on 64bit Amazon Linux/2.6.0
  Tier: WebServer-Standard

Answer 1

我会运行 EB 环境更新和/或替换实例。或者您可以移至 "Storing the Connection String in Amazon S3"

When the environment update is complete, the DB instance's hostname and other connection information are available to your application through the following environment properties:

RDS_HOSTNAME – The hostname of the DB instance. Amazon RDS console label – Endpoint (this is the hostname)

RDS_PORT – The port on which the DB instance accepts connections. The default value varies between DB engines. Amazon RDS console label – Port

RDS_DB_NAME – The database name, ebdb. Amazon RDS console label – DB Name

RDS_USERNAME – The user name that you configured for your database. Amazon RDS console label – Username

RDS_PASSWORD – The password that you configured for your database.

private static Connection getRemoteConnection() {
    if (System.getenv("RDS_HOSTNAME") != null) {
      try {
      Class.forName("org.postgresql.Driver");
      String dbName = System.getenv("RDS_DB_NAME");
      String userName = System.getenv("RDS_USERNAME");
      String password = System.getenv("RDS_PASSWORD");
      String hostname = System.getenv("RDS_HOSTNAME");
      String port = System.getenv("RDS_PORT");
      String jdbcUrl = "jdbc:postgresql://" + hostname + ":" + port + "/" + dbName + "?user=" + userName + "&password=" + password;
      logger.trace("Getting remote connection with connection string from environment variables.");
      Connection con = DriverManager.getConnection(jdbcUrl);
      logger.info("Remote connection successful.");
      return con;
    }
    catch (ClassNotFoundException e) { logger.warn(e.toString());}
    catch (SQLException e) { logger.warn(e.toString());}
    }
    return null;
  }

https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/java-rds.html#java-rds-javase