Add a client for the pod read-log endpoint

[dbolkensteyn]

Command-line: kubectl log <pod-name>
Documentation: https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#read-log-pod-v1-core

From what I read so far on kubernetes/kubernetes#13885, the /log endpoints only expects binary.k8s.io as protocol. Without it (but still sending the *.channel.k8s.io ones), a 403 Forbidden status code is returned.

I'll try to submit a PR for this in the upcoming days, suggestions are welcome.

Right now I'm trying to fit this into WebSocketHandler, but there is already a binary handler that expects the first byte of the message to be the channel number, which is not the case for the /log endpoint. See https://github.com/kubernetes-client/javascript/blob/master/node-client/src/web-socket-handler.ts#L89-L94

[dbolkensteyn]

PR opened, let's discuss there

[chadbr]

@dbolkensteyn Hey Dinesh -- Can you point me to an example of how to use the Log.log(..) method? I have not been able to figure out how to get something out the of the stream: Writable parameter.

Thanks, Chad

[dbolkensteyn]

It's been a while but try something along these lines @chadbr:

const myStream = new stream.Writable({
    write(chunk, encoding, callback) {
      console.log(chunk.toString().trimRight())
      // or do something else more useful to you
      callback()
    }
  })

and then pass myStream as the argument.

[chadbr]

Thanks @dbolkensteyn -- I'm failing to grasp why we would pass a writable stream instead of getting a readable stream from the log function? I'm assuming the function is there to read log streams?

Sorry for the dumb question...

For example, when I call spawn - I get an object back with the process streams:

    // return this object when stdio option is undefined or not specified
    interface ChildProcessWithoutNullStreams extends ChildProcess {
        stdin: Writable;
        stdout: Readable;
        stderr: Readable;

I would have assumed the log function would return something like `stdout: Readable;'? What am I missing?