return empty array for GetAll intead of err

[johnrengelman]

Support template processing where a key may not be available at templating time (i.e. no passing servers for a Consul service health check)

kelseyhightower/confd#102

[kelseyhightower]

@johnrengelman This will break things as we want to ensure if no match is found we return an error. Is the idea being we want an empty list in some cases?

[johnrengelman]

Yes. For example, you have a template for HAProxy that relies on Consul returning the healthy hosts for a service. If there are none, then Consul returns an empty list which would cause an error in confd when the template is processed. But this isn't really an error condition as having no backend servers is a valid state for HAProxy.

[johnrengelman]

Perhaps a new function that doesn't error? GetList?

[okushchenko]

Fixed in 32a4556