feat: ELB URL support

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/#semantic-versioning-200).
 
 ## [?]
+
+### :magic_wand: Added
+- Elastic Load Balancer URL support ([PR#476](https://github.com/awslabs/aws-advanced-jdbc-wrapper/pull/476)).
+
 ### :bug: Fixed
 - Values for the `wrapperLoggerLevel` parameter are no longer case-sensitive ([#PR #481](https://github.com/awslabs/aws-advanced-jdbc-wrapper/pull/481)).
 

docs/using-the-jdbc-driver/using-plugins/UsingTheIamAuthenticationPlugin.md

@@ -28,7 +28,7 @@ IAM database authentication use is limited to certain database engines. For more
 |-------------------|:-------:|:--------:|:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------|
 | `wrapperPlugins`  | String  |    No    | Set to `"iam"` to enable AWS IAM database authentication                                                                                                                                                                                                                                                               | `iam`                                               |
 | `iamDefaultPort`  | String  |    No    | This property will override the default port that is used to generate the IAM token. The default port is determined based on the underlying driver protocol. For now, there is support for `jdbc:postgresql:` and `jdbc:mysql:`. Target drivers with different protocols will require users to provide a default port. | `1234`                                              |
-| `iamHost`         | String  |    No    | This property will override the default hostname that is used to generate the IAM token. The default hostname is derived from the connection string. This parameter is useful when users are connecting with custom endpoints.                                                                                         | `database.cluster-hash.us-east-1.rds.amazonaws.com` |
+| `iamHost`         | String  |    No    | This property will override the default hostname that is used to generate the IAM token. The default hostname is derived from the connection string. This parameter is required when users are connecting with custom endpoints.                                                                                       | `database.cluster-hash.us-east-1.rds.amazonaws.com` |
 | `iamRegion`       | String  |    No    | This property will override the default region that is used to generate the IAM token. The default region is parsed from the connection string.                                                                                                                                                                        | `us-east-2`                                         |
 | `iamExpiration`   | Integer |    No    | This property will override the default expiration time that is assigned to the generated IAM token. The default expiration time is set to be 15 minutes.                                                                                                                                                              | `600`                                               |
 

wrapper/src/main/java/software/amazon/jdbc/util/RdsUtils.java

@@ -125,6 +125,12 @@ public class RdsUtils {
               + "(?<domain>[a-zA-Z0-9]+\\.rds\\.(?<region>[a-zA-Z0-9\\-])+\\.amazonaws\\.com\\.cn)",
           Pattern.CASE_INSENSITIVE);
 
+  private static final Pattern ELB_PATTERN =
+      Pattern.compile(
+          "(?<instance>.+)\\.elb\\."
+              + "((?<region>[a-zA-Z0-9\\-]+)\\.amazonaws\\.com)",
+          Pattern.CASE_INSENSITIVE);
+
   private static final Pattern IP_V4 =
       Pattern.compile(
           "^(([1-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){1}"
@@ -167,6 +173,11 @@ public boolean isRdsProxyDns(final String host) {
     return AURORA_PROXY_DNS_PATTERN.matcher(host).find() || AURORA_CHINA_PROXY_DNS_PATTERN.matcher(host).find();
   }
 
+  public boolean isElbUrl(final String host) {
+    return !StringUtils.isNullOrEmpty(host)
+        && (ELB_PATTERN.matcher(host).find());
+  }
+
   public String getRdsInstanceHostPattern(final String host) {
     if (StringUtils.isNullOrEmpty(host)) {
       return "?";
@@ -196,6 +207,10 @@ public String getRdsRegion(final String host) {
     if (chinaMatcher.find()) {
       return chinaMatcher.group(REGION_GROUP);
     }
+    final Matcher elbMatcher = ELB_PATTERN.matcher(host);
+    if (elbMatcher.find()) {
+      return elbMatcher.group(REGION_GROUP);
+    }
     return null;
   }
 
@@ -277,6 +292,7 @@ public RdsUrlType identifyRdsType(final String host) {
     } else if (isRdsDns(host)) {
       return RdsUrlType.RDS_INSTANCE;
     } else {
+      // ELB URLs will also be classified as other
       return RdsUrlType.OTHER;
     }
   }

wrapper/src/test/java/software/amazon/jdbc/util/RdsUtilsTests.java

@@ -46,6 +46,9 @@ public class RdsUtilsTests {
   private static final String chinaRegionCustomDomain =
       "custom-test-name.cluster-custom-XYZ.rds.cn-northwest-1.amazonaws.com.cn";
 
+  private static final String usEastRegionElbUrl =
+      "elb-name.elb.us-east-2.amazonaws.com";
+
   @Test
   public void testIsRdsDns() {
     RdsUtils target = new RdsUtils();
@@ -55,6 +58,7 @@ public void testIsRdsDns() {
     assertTrue(target.isRdsDns(usEastRegionInstance));
     assertTrue(target.isRdsDns(usEastRegionProxy));
     assertTrue(target.isRdsDns(usEastRegionCustomDomain));
+    assertFalse(target.isRdsDns(usEastRegionElbUrl));
 
     assertTrue(target.isRdsDns(chinaRegionCluster));
     assertTrue(target.isRdsDns(chinaRegionClusterReadOnly));
@@ -91,6 +95,7 @@ public void testIsRdsClusterDns() {
     assertFalse(target.isRdsClusterDns(usEastRegionInstance));
     assertFalse(target.isRdsClusterDns(usEastRegionProxy));
     assertFalse(target.isRdsClusterDns(usEastRegionCustomDomain));
+    assertFalse(target.isRdsClusterDns(usEastRegionElbUrl));
 
     assertTrue(target.isRdsClusterDns(chinaRegionCluster));
     assertTrue(target.isRdsClusterDns(chinaRegionClusterReadOnly));
@@ -108,6 +113,7 @@ public void testIsWriterClusterDns() {
     assertFalse(target.isWriterClusterDns(usEastRegionInstance));
     assertFalse(target.isWriterClusterDns(usEastRegionProxy));
     assertFalse(target.isWriterClusterDns(usEastRegionCustomDomain));
+    assertFalse(target.isWriterClusterDns(usEastRegionElbUrl));
 
     assertTrue(target.isWriterClusterDns(chinaRegionCluster));
     assertFalse(target.isWriterClusterDns(chinaRegionClusterReadOnly));
@@ -125,6 +131,7 @@ public void testIsReaderClusterDns() {
     assertFalse(target.isReaderClusterDns(usEastRegionInstance));
     assertFalse(target.isReaderClusterDns(usEastRegionProxy));
     assertFalse(target.isReaderClusterDns(usEastRegionCustomDomain));
+    assertFalse(target.isReaderClusterDns(usEastRegionElbUrl));
 
     assertFalse(target.isReaderClusterDns(chinaRegionCluster));
     assertTrue(target.isReaderClusterDns(chinaRegionClusterReadOnly));
@@ -143,6 +150,7 @@ public void testGetRdsRegion() {
     assertEquals(expectedHostPattern, target.getRdsRegion(usEastRegionInstance));
     assertEquals(expectedHostPattern, target.getRdsRegion(usEastRegionProxy));
     assertEquals(expectedHostPattern, target.getRdsRegion(usEastRegionCustomDomain));
+    assertEquals(expectedHostPattern, target.getRdsRegion(usEastRegionElbUrl));
 
     final String chinaExpectedHostPattern = "cn-northwest-1";
     assertEquals(chinaExpectedHostPattern, target.getRdsRegion(chinaRegionCluster));