Add health checks + kubernetes liveness/readiness probes

[0dragosh]

It would be great to have at least one HTTP endpoint that we can use for a health check at deployment.

Could be as simple as:

@app.route('/healthz')
def live():
  return "Live!"

@app.route('/readyz')
def ready():
  return "Ready!"

after config is loaded. (example is using flask)

[RemiRigal]

Thank you for opening the issue, I just merged #21 that adds the health-check HTTP server.

You can use one of those endpoints:

• / or /health that returns a response code 200 if healthy, 400 otherwise. The response body is: {"healthy": true/false}
• /ready that returns a response code 200 if ready, 400 otherwise. The response body is: {"ready": true/false}

[RemiRigal]

FYI I've changed the port on which the health-check server is running to 9880 in order to avoid the need for elevated privileges when running the application without Docker. This change will be included in the next release.