openstack builder: support using existing keypair

builder/openstack/builder.go

@@ -77,6 +77,8 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepKeyPair{
 			Debug:        b.config.PackerDebug,
 			DebugKeyPath: fmt.Sprintf("os_%s.pem", b.config.PackerBuildName),
+			KeyPairName:          b.config.SSHKeyPairName,
+			PrivateKeyFile:       b.config.RunConfig.Comm.SSHPrivateKey,
 		},
 		&StepRunSourceServer{
 			Name:             b.config.ImageName,

builder/openstack/run_config.go

@@ -11,6 +11,7 @@ import (
 // image and details on how to access that launched image.
 type RunConfig struct {
 	Comm         communicator.Config `mapstructure:",squash"`
+	SSHKeyPairName string              `mapstructure:"ssh_keypair_name"`
 	SSHInterface string              `mapstructure:"ssh_interface"`
 
 	SourceImage      string   `mapstructure:"source_image"`

builder/openstack/step_key_pair.go

@@ -2,6 +2,7 @@ package openstack
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"runtime"
 
@@ -14,10 +15,27 @@ import (
 type StepKeyPair struct {
 	Debug        bool
 	DebugKeyPath string
+	KeyPairName          string
+	PrivateKeyFile       string
+
 	keyName      string
 }
 
 func (s *StepKeyPair) Run(state multistep.StateBag) multistep.StepAction {
+	if s.PrivateKeyFile != "" {
+		privateKeyBytes, err := ioutil.ReadFile(s.PrivateKeyFile)
+		if err != nil {
+			state.Put("error", fmt.Errorf(
+				"Error loading configured private key file: %s", err))
+			return multistep.ActionHalt
+		}
+
+		state.Put("keyPair", s.KeyPairName)
+		state.Put("privateKey", string(privateKeyBytes))
+
+		return multistep.ActionContinue
+	}
+
 	config := state.Get("config").(Config)
 	ui := state.Get("ui").(packer.Ui)
 
@@ -81,6 +99,11 @@ func (s *StepKeyPair) Run(state multistep.StateBag) multistep.StepAction {
 }
 
 func (s *StepKeyPair) Cleanup(state multistep.StateBag) {
+	// If we used an SSH private key file, do not go about deleting
+	// keypairs
+	if s.PrivateKeyFile != "" {
+		return
+	}
 	// If no key name is set, then we never created it, so just return
 	if s.keyName == "" {
 		return