cmd/jujud: implement uniter upgrade

cmd/jujud/machine.go

Index: cmd/jujud/machine.go
=== modified file 'cmd/jujud/machine.go'
--- cmd/jujud/machine.go	2012-09-12 15:35:55 +0000
+++ cmd/jujud/machine.go	2012-09-28 15:15:49 +0000
@@ -4,7 +4,6 @@
 	"fmt"
 	"launchpad.net/gnuflag"
 	"launchpad.net/juju-core/cmd"
-	"launchpad.net/juju-core/environs"
 	"launchpad.net/juju-core/log"
 	"launchpad.net/juju-core/state"
 	"launchpad.net/juju-core/worker/machiner"
@@ -49,20 +48,18 @@
 	for a.tomb.Err() == tomb.ErrStillAlive {
 		log.Printf("machine agent starting")
 		err := a.runOnce()
-		if ug, ok := err.(*UpgradedError); ok {
-			tools, err1 := environs.ChangeAgentTools(a.Conf.DataDir, "machine", ug.Binary)
-			if err1 == nil {
-				log.Printf("exiting to upgrade to %v from %q", tools.Binary, tools.URL)
+		if ug, ok := err.(*UpgradeReadyError); ok {
+			if err = ug.ChangeAgentTools(); err == nil {
 				// Return and let upstart deal with the restart.
-				return nil
+				return ug
 			}
-			err = err1
 		}
+		log.Printf("machiner: %v", err)
 		select {
 		case <-a.tomb.Dying():
 			a.tomb.Kill(err)
 		case <-time.After(retryDelay):
-			log.Printf("restarting machiner after error: %v", err)
+			log.Printf("rerunning machiner")
 		}
 	}
 	return a.tomb.Err()