JSON encoded string input

[radianbaskoro]

I have a use case to show deployment progress with multi line messages. This PR is for adding an optional JSON encoded string input for the frames.

In case of badly formed JSON string, it will print an error message and still use the original frame as the message.

[mroth]

Thanks @radianbaskoro! Sorry for the delay.

I'm trying to understand the use case a bit better so I can offer feedback. What tool is the output coming from, what what does it's typical output look like?

[radianbaskoro]

Output comes from kubectl to query my kubernetes cluster status during deployment. It would look something like:

$ kubectl get pods
NAME     READY     STATUS        RESTARTS   AGE
pod-0    1/1       Running       0          4m
pod-1    1/1       Running       0          2m
pod-2    0/1       Pending       0          2s
pod-3    1/1       Terminating   0          10d

The idea is to notify the progression of deployment from our CI/CD pipeline to our slack channel, and allow us to make any intervention if needed.

[mroth]

Got it. So in this case, kubectl get pods returns a single status update, with normal line breaks. So are you running this through some sort of other command that runs it repeatedly, and then piping that through some other command to do the JSON encoding?

(It's been a number of years since I touched this library, so I've decided to do a general cleanup, which may result in minor API changes. I'll also hopefully be able to generalize and expose the underlying library API, so for more complex usage, it may make more sense to rig it via the Go library instead of the CLI client.)