feat: builder docker/node and sdk-js

[hacdias]

This PR is aligned with the efforts in testground/sdk-js#1.

• Adds a docker/node builder with the following base Dockerfile:

   ARG BASE_IMAGE
   FROM ${BASE_IMAGE} AS builder
   ENV PLAN_DIR /plan
   WORKDIR /plan
   COPY . /
   RUN npm ci
   EXPOSE 6060
   ENTRYPOINT [ "npm", "start"]
  

• Adds a test plan example-js with the following tests:
  • pingpong
  • sync
  • failure
  • output (not complete because metrics aren't finished yet)
• Adds example-js/pingpong to CI

[hacdias]

We have to make network.Config the most compatible possible. Next week, I will tackle on what @raulk mentioned in the linked PR and will also implement an Unmarshaller/Decoder for that struct. Done: testground/sdk-go#34

Some things such as net.IPNet are not easily converted to the same thing as Go. My suggestion is to just pass around the string CIDR. That will virtually work on all implementations since there's always a function to convert CIDRs to native structs.

We can keep using net.IPNet in Go. I'll just need to implement an unmarshaller.

[raulk]

Yeah, I think struct tags will do for the casing. And for IPNet, there's actually a marshaller/unmarshaller you can use. Let me try digging it up!

[raulk]

Here it is: https://github.com/testground/sdk-go/blob/master/runtime/runparams.go

[hacdias]

Just throwing it out again: I think we should collect all this types in some place! 😆 (cycles!) Gonna move IPNet to ptypes!

[hacdias]

I'm changing the base of this PR to #1154 because that one includes the newer SDK with the updates to all tests. However, I'd prefer if we could merge #1154 into master when possible, since that one is not even based on master.

[hacdias]

Update: ping-pong test working!

[hacdias]

@nonsense @raulk I feel this PR is finished. Even though sdk-js isn't complete (missing metrics before releasing 1.0), I feel this PR is ready for review and should be merged. Later, we can make further changes if needed.

[nonsense]

Overall LGTM!

[hacdias]

I'm going to address the comments and then merge!