fleetctl: set --driver=etcd if --endpoint is etcd-like

[bcwaldon]

There is one remaining wart of the switch from --driver=etcd to --driver=API. If someone had been using fleetctl with a custom endpoint like so:

fleetctl --endpoint http://example.com:4001 list-machines

They now all of a sudden get directed to the fleet API rather than etcd. Given that we can tell (based on the port) that the user wants to use etcd, the default of --driver in this case should remain "etcd".

[crawford]

7 levels of indentation?

[bcwaldon]

deal with it

[jonboulle]

UMM

[crawford]

How does this look if it's in an anonymous function, returning after failed conditions?

[crawford]

Or if you wrap the check in a recover() and just assume that the Split, Parse, and SplitHostPort worked.

[crawford]

visited := make(map[string]bool, 0)
...
if !visited["driver"] && visited["endpoint"] {
    if u, err := url.Parse(strings.Split(globalFlags.Endpoint, ",")[0]); err == nil  {
        if _, port, err := net.SplitHostPort(u.Host); err == nil && (port == "4001" || port == "2379") {
            log.Debugf("Defaulting to --driver=%s as --endpoint appears to be etcd", clientDriverEtcd)
            globalFlags.ClientDriver = clientDriverEtcd
        }
    }
}

[crawford]

LGTM