Enable Datadog profiler for Starrocks FE/BE deployment

[dengliu]

Ideally, we can use a init container to download the ddprofile binary. and share it with the main container via emptydir. The version can be configurable in values.yaml as well as the boolean for enabling ddprofile

ddprofile:
  enabled: true
  version: [0.14.1](https://github.com/DataDog/ddprof/releases/tag/v0.14.1)

https://docs.datadoghq.com/profiler/enabling/ddprof/?tab=environmentvariables

https://docs.datadoghq.com/profiler/enabling/java/?tab=datadogprofiler

[kevincai]

what's the size of the binary? is it possible to mount the binary into container with configmap?

[dengliu]

ddprof is 13MB. It's a common practice to use initContainers to share binaries to main container. E.g. the dd-java-agent.jar is already available from https://hub.docker.com/r/datadog/dd-lib-java-init

[yandongxiao]

We will add a field preStartScriptLocation, and you can down load the binary before container process start. see https://github.com/StarRocks/starrocks-kubernetes-operator/pull/355