You can use the following snippet as a replacement for the default connection-pool provided by SpringBoot/Tomcat. It will refresh the token password every 10 minutes, since the token is valid for 15 minutes. Also, it assumes the region can be extracted from the DNS hostname. If this is not the case, you'll need to specify the region to use.
public class RdsIamAuthDataSource extends org.apache.tomcat.jdbc.pool.DataSource {
private static final Logger LOG = LoggerFactory.getLogger(RdsIamAuthDataSource.class);
/**
* The Java KeyStore (JKS) file that contains the Amazon root CAs
*/
public static final String RDS_CACERTS = "/rds-cacerts";
/**
* Password for the ca-certs file.
*/
public static final String PASSWORD = "changeit";
public static final int DEFAULT_PORT = 3306;
@Override
public ConnectionPool createPool() throws SQLException {
return pool != null ? pool : createPoolImpl();
}
protected synchronized ConnectionPool createPoolImpl() throws SQLException {
return pool = new RdsIamAuthConnectionPool(poolProperties);
}
public static class RdsIamAuthConnectionPool extends ConnectionPool implements Runnable {
private RdsIamAuthTokenGenerator rdsIamAuthTokenGenerator;
private String host;
private String region;
private int port;
private String username;
private Thread tokenThread;
public RdsIamAuthConnectionPool(PoolConfiguration prop) throws SQLException {
super(prop);
}
@Override
protected void init(PoolConfiguration prop) throws SQLException {
try {
URI uri = new URI(prop.getUrl().substring(5));
this.host = uri.getHost();
this.port = uri.getPort();
if (this.port < 0) {
this.port = DEFAULT_PORT;
}
this.region = StringUtils.split(this.host,'.')[2]; // extract region from rds hostname
this.username = prop.getUsername();
this.rdsIamAuthTokenGenerator = RdsIamAuthTokenGenerator.builder().credentials(new DefaultAWSCredentialsProviderChain()).region(this.region).build();
updatePassword(prop);
final Properties props = prop.getDbProperties();
props.setProperty("useSSL","true");
props.setProperty("requireSSL","true");
props.setProperty("trustCertificateKeyStoreUrl",getClass().getResource(RDS_CACERTS).toString());
props.setProperty("trustCertificateKeyStorePassword", PASSWORD);
super.init(prop);
this.tokenThread = new Thread(this, "RdsIamAuthDataSourceTokenThread");
this.tokenThread.setDaemon(true);
this.tokenThread.start();
} catch (URISyntaxException e) {
throw new RuntimeException(e.getMessage());
}
}
@Override
public void run() {
try {
while (this.tokenThread != null) {
Thread.sleep(10 * 60 * 1000); // wait for 10 minutes, then recreate the token
updatePassword(getPoolProperties());
}
} catch (InterruptedException e) {
LOG.debug("Background token thread interrupted");
}
}
@Override
protected void close(boolean force) {
super.close(force);
Thread t = tokenThread;
tokenThread = null;
if (t != null) {
t.interrupt();
}
}
private void updatePassword(PoolConfiguration props) {
String token = rdsIamAuthTokenGenerator.getAuthToken(GetIamAuthTokenRequest.builder().hostname(host).port(port).userName(this.username).build());
LOG.debug("Updated IAM token for connection pool");
props.setPassword(token);
}
}
}
Please note that you'll need to import Amazon's root/intermediate certificates to establish a trusted connection. The example code above assumes that the certificates have been imported into a file called 'rds-cacert' and is available on the classpath. Alternatively, you can also import them into the JVM 'cacerts' file.
To use this data-source, you can use the following properties for Spring:
datasource:
url: jdbc:mysql://dbhost.xyz123abc.us-east-1.rds.amazonaws.com/dbname
username: iam_app_user
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.mydomain.jdbc.RdsIamAuthDataSource
Using Spring Java config:
@Bean public DataSource dataSource() {
PoolConfiguration props = new PoolProperties();
props.setUrl("jdbc:mysql://dbname.abc123xyz.us-east-1.rds.amazonaws.com/dbschema");
props.setUsername("iam_dbuser_app");
props.setDriverClassName("com.mysql.jdbc.Driver");
return new RdsIamAuthDataSource(props);
}
UPDATE: When using MySQL, you can also decide to use the MariaDB JDBC driver, which has builtin support for IAM authentication:
spring:
datasource:
host: dbhost.cluster-xxx.eu-west-1.rds.amazonaws.com
url: jdbc:mariadb:aurora//${spring.datasource.host}/db?user=xxx&credentialType=AWS-IAM&useSsl&serverSslCert=classpath:rds-combined-ca-bundle.pem
type: org.mariadb.jdbc.MariaDbPoolDataSource
The above requires MariaDB and AWS SDK libraries, and needs the CA-bundle in the classpath
