Merge pull request #4597 from mitchellh/fix4452

fix ssh agent authentication

builder/amazon/common/step_key_pair.go

@@ -107,7 +107,7 @@ func (s *StepKeyPair) Cleanup(state multistep.StateBag) {
 	// If no key name is set, then we never created it, so just return
 	// If we used an SSH private key file, do not go about deleting
 	// keypairs
-	if s.PrivateKeyFile != "" || s.KeyPairName != "" {
+	if s.PrivateKeyFile != "" || (s.KeyPairName == "" && s.keyName == "") {
 		return
 	}
 

builder/amazon/common/step_run_source_instance.go

@@ -41,7 +41,10 @@ type StepRunSourceInstance struct {
 
 func (s *StepRunSourceInstance) Run(state multistep.StateBag) multistep.StepAction {
 	ec2conn := state.Get("ec2").(*ec2.EC2)
-	keyName := state.Get("keyPair").(string)
+	var keyName string
+	if name, ok := state.GetOk("keyPair"); ok {
+		keyName = name.(string)
+	}
 	securityGroupIds := aws.StringSlice(state.Get("securityGroupIds").([]string))
 	ui := state.Get("ui").(packer.Ui)