added TCP port to discovery address

README.md

@@ -4,6 +4,11 @@
 This neo4j plugin implements cluster discovery for a cluster deployed in an AWS EC2 Auto-scaling group. 
 It retrieves the list of network addresses of the group's VMs, and feeds it to Neo4j's cluster discovery module.
 
+Notes:
+- It retrieves the VMs' private DnsName or IpAddress.
+- It retrieves the discovery TCP port from the neo4j setting "server.discovery.listen_address"
+
+
 **Compatilibity**
 
 Neo4j 5.7+
@@ -32,3 +37,5 @@ The AWS User requires the following permissions :
 - "ec2:DescribeInstances",
 - "autoscaling:DescribeAutoScalingGroups"
 
+
+The auto-scaling group VMs require a Security Group that allows traffic on TCP ports 5000, 6000, 7000, 7688 (for internal cluster communication) as well as TCP ports 7474 and 7687 (for external access).

src/main/java/cs/neo4j/AsgResolver.java

@@ -5,6 +5,7 @@
 import static java.lang.String.format;
 
 import com.neo4j.causalclustering.discovery.resolve.BaseRemotesResolver;
+import com.neo4j.configuration.DiscoverySettings;
 import org.neo4j.annotations.service.ServiceProvider;
 import org.neo4j.common.DependencyResolver;
 import org.neo4j.configuration.Config;
@@ -22,6 +23,7 @@ public class AsgResolver extends BaseRemotesResolver {
     private String awsKey;
     private String awsSecret;
     private String awsRegion;
+    private int discoveryPort;
     private AwsClient awsClient;
     private InternalLog log;
 
@@ -36,6 +38,9 @@ protected void internalInit(Config config, LogService logService, DependencyReso
         awsKey = checkConfig(config, Ec2Settings.aws_key);
         awsSecret = checkConfig(config, Ec2Settings.aws_secret);
         awsRegion = checkConfig(config, Ec2Settings.aws_region);
+
+        discoveryPort = checkConfig(config, DiscoverySettings.discovery_listen_address).getPort();
+
         log = logService.getUserLog(AsgResolver.class);
         log.info("Init of discovery plugin "+this.configDescription());
         awsClient = externalDependencies.containsDependency(AwsClient.class)
@@ -46,7 +51,12 @@ protected void internalInit(Config config, LogService logService, DependencyReso
     @Override
     protected Stream<SocketAddress> resolveInternal() {
         try {
-            return awsClient.getVmAddressesByAsgName(selector).map(s -> new SocketAddress(s));
+            return awsClient.getVmAddressesByAsgName(selector)
+                    .map(s -> {
+                        SocketAddress addr = new SocketAddress(s, discoveryPort);
+
+                        return addr;
+                    });
         } catch (Exception e) {
             log.error("Failed discovery "+e.getMessage());
         }