[Functions] Support skywalking for performance monitoring

[xuesongxs]

Modifications

Describe the modifications you've done.

Verifying this change

update:
Function.proto
RuntimeUtils.java
FunctionConfig.java
CmdFunctions.java
FunctionConfigUtils.java

add:
SkywalkingConfig.java
SkywalkingConfigUtils.java

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (yes)
• Anything that affects deployment: (no)

Documentation

• Does this pull request introduce a new feature? (yes)
  Pulsar function supports skywalking

Usage:
bin/pulsar-admin functions create
--jar examples/filter.jar
--classname com.newland.filter.FilterFunction
--tenant public
--namespace default
--name filtertest3
--inputs persistent://public/default/filter-input
--output persistent://public/default/rr-input
--skywalking-agent-conf-path /opt/app/pulsar-2.4.1/skywalking/agent/config/agent.config
--skywalking-agent-jar-path /opt/app/pulsar-2.4.1/skywalking/agent/skywalking-agent.jar
--skywalking-backend-service 127.0.0.1:41800

skywalking-agent-conf-path、skywalking-backend-service，It can exist at the same time or fill in only one。

[sijie]

@xuesong172500 thank you for submitting the pull request for adding Skywalking support for Pulsar Functions! It is a great initiative and I believe that it will take Pulsar Functions into the next level.

However, the implementation seems to be tightly coupled with skywalking. I think we need to step back a bit and think about a general framework for adding extensions and plugins to functions. Otherwise, it becomes unmanageable.

/cc @wolfstudy @jerrypeng @srkukarni for inputs on this feature.

[sijie]

forgot to /cc @codelipenghui as he did the Skywalking and Pulsar integration before.

[codelipenghui]

@sijie

However, the implementation seems to be tightly coupled with skywalking. I think we need to step back a bit and think about a general framework for adding extensions and plugins to functions. Otherwise, it becomes unmanageable.

Totally agree with you.

[jerrypeng]

@sijie I agree. Lets create a generic interface for something like this

[tisonkun]

Closed as stale, conflict, and no consensus.