[health-checker] Added logging messages

These will probably be useful in the future.

Change-Id: Ibc41abbd25da74f247db56d7698b7bf0df104b2f
diff --git a/cmd/health_checker/main.go b/cmd/health_checker/main.go
index 3b3b376..6617f6e 100644
--- a/cmd/health_checker/main.go
+++ b/cmd/health_checker/main.go
@@ -121,6 +121,7 @@
 	}
 
 	// Wait for Zedboot to come back up.
+	log.Printf("Waiting for Zedboot to come back up.")
 	start := time.Now()
 	for ; time.Since(start) < zedbootWaitDuration;  {
 		time.Sleep(zedbootCheckInterval)
@@ -130,6 +131,7 @@
 	}
 
 	// If we get here, Zedboot never came back up, so we need to powercycle the device.
+	log.Printf("Zedboot did not come up; attempting powercycle")
 	if err := device.Powercycle(ctx); err != nil {
 		return err
 	}
diff --git a/devices/power.go b/devices/power.go
index 4843fca..d94a9eb 100644
--- a/devices/power.go
+++ b/devices/power.go
@@ -9,6 +9,7 @@
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"time"
 
 	"go.fuchsia.dev/fuchsia/tools/net/sshutil"
@@ -68,9 +69,12 @@
 // additionally uses the given configuration to reboot the device if specified.
 func (c PowerClient) RebootDevice(signers []ssh.Signer, nodename string, serial io.ReadWriter) error {
 	var rebooter Rebooter
+	log.Printf("Attempting to soft reboot device %s", nodename)
 	if serial != nil {
+		log.Printf("Using serial to reboot.")
 		rebooter = NewSerialRebooter(serial)
 	} else {
+		log.Printf("Using SSH to reboot.")
 		rebooter = NewSSHRebooter(nodename, signers)
 	}
 	return rebooter.reboot()
@@ -78,13 +82,16 @@
 
 // Powercycle the device using an out of band method
 func (c PowerClient) Powercycle(nodename string, serial io.ReadWriter) error {
+	log.Printf("Attempting to powercycle device %s", nodename)
 	switch c.Type {
 		case "amt":
+			log.Printf("Using AMT to powercycle.")
 			return AMTReboot(c.Host, c.Username, c.Password)
 		case "wol":
 			if serial == nil {
 				return errors.New(fmt.Sprintf("WOL Reboot requires serial connection."))
 			}
+			log.Printf("Using WOL to powercycle")
 			if err := WOLReboot(botBroadcastAddr, botInterface, c.HostMACAddr); err != nil {
 				return err
 			}
@@ -92,6 +99,7 @@
 			if serial == nil {
 				return errors.New(fmt.Sprintf("PDU Reboot requires serial connection."))
 			}
+			log.Printf("Using PDU to powercycle")
 			if err := PDUReboot(c.PDUPort, c.Host, c.Username, c.Password); err != nil {
 				return err
 			}
@@ -99,6 +107,7 @@
 			return errors.New(fmt.Sprintf("%v does not have AMT, WOL, or PDU support. Cannot powercycle.", nodename))
 	}
 	// Send dm reboot-recovery to the device so that it always boots into zedboot.
+	log.Printf("Powercycle complete; using serial to send dm reboot recovery.")
 	time.Sleep(powercycleWait)
 	rebooter := NewSerialRebooter(serial)
 	return rebooter.reboot()