DD_AGENT_HOST set as the host IP fails in an IPv6-only EKS environment

[jungnoh]

I am trying to instrument a Java application orchestrated in an EKS cluster. I've set DD_AGENT_HOST as guided in Kubernetes APM - Trace Collection docs with the following YAML.

        env:
          - name: DD_AGENT_HOST
            valueFrom:
              fieldRef:
                fieldPath: status.hostIP

This was not a problem and worked well in a IPv4 EKS environment. However, the Agent fails when an IPv6 address is given:

[dd.trace 2024-10-02 22:29:13:511 +0900] [main] ERROR datadog.trace.bootstrap.Agent - Throwable thrown while installing the Datadog Tracer                                                                          java.lang.reflect.InvocationTargetException                                                                                                                                                                             at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)                                                                                                                                   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)                                                                                                                 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)                                                                                                         at java.base/java.lang.reflect.Method.invoke(Method.java:569)                                                                                                                                                       at datadog.trace.bootstrap.Agent.installDatadogTracer(Agent.java:642)                                                                                                                                               at datadog.trace.bootstrap.Agent.access$400(Agent.java:68)                                                                                                                                                          at datadog.trace.bootstrap.Agent$InstallDatadogTracerCallback.execute(Agent.java:525)                                                                                                                               at datadog.trace.bootstrap.Agent.start(Agent.java:351)                                                                                                                                                              at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)                                                                                                                                   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)                                                                                                                 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)                                                                                                         at java.base/java.lang.reflect.Method.invoke(Method.java:569)                                                                                                                                                       at datadog.trace.bootstrap.AgentBootstrap.agentmainImpl(AgentBootstrap.java:155)                                                                                                                                    at datadog.trace.bootstrap.AgentBootstrap.agentmain(AgentBootstrap.java:72)                                                                                                                                         at datadog.trace.bootstrap.AgentBootstrap.premain(AgentBootstrap.java:60)                                                                                                                                           at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)                                                                                                                                   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)                                                                                                                 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)                                                                                                         at java.base/java.lang.reflect.Method.invoke(Method.java:569)                                                                                                                                                       at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:491)                                                                                                          at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:503)                                                                                                     Caused by: java.lang.IllegalArgumentException: Bad agent URL: http://2406:da1a:2c6:5304::b65a:8126                                                                                                                      at datadog.communication.ddagent.SharedCommunicationObjects.createRemaining(SharedCommunicationObjects.java:35)                                                                                                     at datadog.trace.agent.core.CoreTracer.<init>(CoreTracer.java:648)                                                                                                                                                  at datadog.trace.agent.core.CoreTracer.<init>(CoreTracer.java:122)                                                                                                                                                  at datadog.trace.agent.core.CoreTracer$CoreTracerBuilder.build(CoreTracer.java:483)                                                                                                                                 at datadog.trace.agent.tooling.TracerInstaller.installGlobalTracer(TracerInstaller.java:26)                                                                                                                         ... 21 more                                                                                                                                                                                                     [dd.trace 2024-10-02 22:29:13:528 +0900] [main] CRITICAL com.datadog.appsec.AppSecSystem - AppSec could not start because of an unexpected error. No security activities will be collected. Please contact support ajava.lang.IllegalArgumentException: Bad agent URL: http://2406:da1a:2c6:5304::b65a:8126                                                                                                                                 at datadog.communication.ddagent.SharedCommunicationObjects.createRemaining(SharedCommunicationObjects.java:35)                                                                                                     at datadog.communication.ddagent.SharedCommunicationObjects.createPoller(SharedCommunicationObjects.java:89)                                                                                                        at datadog.communication.ddagent.SharedCommunicationObjects.configurationPoller(SharedCommunicationObjects.java:76)
    at com.datadog.appsec.AppSecSystem.doStart(AppSecSystem.java:73)
    at com.datadog.appsec.AppSecSystem.start(AppSecSystem.java:48)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)

For okhttp to parse the URL correctly, it seems like the URL should have been built as http://[2406:da1a:2c6:5304::b65a]:8126. I am using dd-trace-java 1.70.0.