Enhancement: Display error from datacenter connection failure

[jaredledvina]

Currently the error message in the UI is rather generic when Uchiwa fails to connect to a datacenter. It'd be great if a more specific error was shown.

Expected Behavior

If Uchiwa fails to connect to a Sensu API endpoint, in the UI display the reason. For example, if the error is:

{"timestamp":"2017-03-26T17:33:15.939590722Z","level":"warn","message":"GET http://sensu-api:4567/stashes returned: 401 Unauthorized"}

The UI error could be along the lines of:

Connection failed to datacenter $name_here with reason: 401 Unauthorized

Current Behavior

Only a generic error message is displayed requiring log diving to determine simple misconfigurations.

Context

Looking to reduce the amount of log diving required when I've made a dumb config error.

Your Environment

• Uchiwa version used: 0.23.0
• Sensu version used: 0.28.4
• Operating System and version (e.g. Ubuntu 14.04): Debian Jessie

[jaredledvina]

Thanks!