libnet: remove Endpoint.anonymous

No more concept of "anonymous endpoints". The equivalent is now an
endpoint with no DNSNames set.

Some of the code removed by this commit was mutating user-supplied
endpoint's Aliases to add container's short ID to that list. In order to
preserve backward compatibility for the ContainerInspect endpoint, this
commit also takes care of adding that short ID (and the container
hostname) to `EndpointSettings.Aliases` before returning the response.

Signed-off-by: Albin Kerouanton <albinker@gmail.com>

daemon/inspect.go

@@ -15,6 +15,8 @@ import (
 	"github.com/docker/docker/daemon/config"
 	"github.com/docker/docker/daemon/network"
 	"github.com/docker/docker/errdefs"
+	"github.com/docker/docker/internal/sliceutil"
+	"github.com/docker/docker/pkg/stringid"
 	"github.com/docker/go-connections/nat"
 )
 
@@ -27,6 +29,18 @@ func (daemon *Daemon) ContainerInspect(ctx context.Context, name string, size bo
 		return daemon.containerInspectPre120(ctx, name)
 	case versions.Equal(version, "1.20"):
 		return daemon.containerInspect120(name)
+	case versions.LessThan(version, "1.45"):
+		ctr, err := daemon.ContainerInspectCurrent(ctx, name, size)
+		if err != nil {
+			return nil, err
+		}
+
+		shortCID := stringid.TruncateID(ctr.ID)
+		for _, ep := range ctr.NetworkSettings.Networks {
+			ep.Aliases = sliceutil.Dedup(append(ep.Aliases, shortCID, ctr.Config.Hostname))
+		}
+
+		return ctr, nil
 	default:
 		return daemon.ContainerInspectCurrent(ctx, name, size)
 	}