Add K6 script for initial load test

[mkurapov]

Context

In order to create initial load/stress tests for the local playground as part of the performance testing story, we should add a K6 script to the repository that simulates a simple peer to peer payment using the GraphQL APIs: createReceiver createQuote and createOutgoingPayment.

For now, we can set the scenario to be quite small, a single virtual user (VU) across 10 minutes. We should be able to see the local playground Grafana dashboard properly populate with metrics (and traces).

Since the local playground is within docker, we will need to run this script in docker as well, e.g.
docker run --rm -i grafana/k6 run - <script.js

Make sure that the k6 docker container is run within the same rafiki network as the other containers.

The K6 documentation can be found here.

Tasks

• Add a K6 script in the repository that simulates a peer to peer payment between cloud-nine-wallet and happy-life-bank
• Add README for running the script