Access to etcd keys which are not present

[mulbc]

Tendrl-api is trying to access keys on first boot, which are not present. This causes a complete failure and no apparent way to fix it.

• This is currently breaking tendrl-ansible build! -
  More info over here:
  Tendrl-API fails to be set up properly tendrl-ansible#1

[mkudlej]

I think this is knows issue. QE opinion is here #31 (comment)
Summary: API should clearly report issue and it should not crash with stacktrace.

[brainfunked]

This particular key is absolutely mandatory for the API to function. While the exception could be caught and handled, the response to the requests would still be a 5xx. This is because the prerequisites for the API to function aren't setup and no queries can be responded to.

The best I can think of is to provide a helpful message as a response rather than a backtrace.

[anivargi]

@zeichenanonym The API never tries to load anything from etcd (keys) when it is started, it only looks for the etcd config.
If you have a proper etcd config and you try hostname/api/1.0/ping the API does handle it and returns a {"errors":{"message":"Not found."}} with 404 HTTP status.

The purpose of the ping in this case is to know everything is configured properly with definitions file.

We could add something like /api/1.0/status to just know if the API is up and running.