network_interface type=direct, ssh agent added to libvirt_uri

builder/libvirt/network/direct.go

@@ -0,0 +1,35 @@
+package network
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/packer-plugin-sdk/template/interpolate"
+	"libvirt.org/go/libvirtxml"
+)
+
+type DirectNetworkInterface struct {
+	// For `type = "direct" interfaces, the name of the host direct device which the domain connects to
+	Dev string `mapstructure:"dev" required:"false"`
+	Mode string `mapstructure:"mode" required:"false"`
+}
+
+func (ni *DirectNetworkInterface) PrepareConfig(ctx *interpolate.Context) (warnings []string, errs []error) {
+	errs = []error{}
+	if ni.Dev == "" {
+		errs = append(errs, fmt.Errorf("network interfaces with type=direct must specify dev"))
+	}
+	if ni.Mode == "" {
+		errs = append(errs, fmt.Errorf("network interfaces with type=direct must specify mode"))
+	}
+
+	return
+}
+
+func (ni DirectNetworkInterface) UpdateDomainInterface(domainInterface *libvirtxml.DomainInterface) {
+	domainInterface.Source = &libvirtxml.DomainInterfaceSource{
+		Direct: &libvirtxml.DomainInterfaceSourceDirect{
+			Dev: ni.Dev,
+			Mode: ni.Mode,
+		},
+	}
+}

builder/libvirt/network/network.go

@@ -24,6 +24,7 @@ type NetworkInterface struct {
 	Model string `mapstructure:"model" required:"false"`
 
 	Bridge  BridgeNetworkInterface  `mapstructure:",squash"`
+	Direct  DirectNetworkInterface  `mapstructure:",squash"`
 	Managed ManagedNetworkInterface `mapstructure:",squash"`
 }
 
@@ -44,6 +45,8 @@ func (ni *NetworkInterface) PrepareConfig(ctx *interpolate.Context) (warnings []
 	switch ni.Type {
 	case "managed", "network":
 		w, e = ni.Managed.PrepareConfig(ctx)
+	case "direct":
+		w, e = ni.Direct.PrepareConfig(ctx)
 	case "bridge":
 		w, e = ni.Bridge.PrepareConfig(ctx)
 	default:
@@ -74,6 +77,8 @@ func (ni NetworkInterface) DomainInterface() *libvirtxml.DomainInterface {
 	}
 
 	switch ni.Type {
+	case "direct":
+		ni.Direct.UpdateDomainInterface(&domainInterface)
 	case "bridge":
 		ni.Bridge.UpdateDomainInterface(&domainInterface)
 	case "managed":

libvirt-utils/libvirt_uri.go

@@ -52,7 +52,7 @@ func (uri *LibvirtUri) GetExtra(p LibvirtUriExtraParam) (string, bool) {
 }
 
 func (uri *LibvirtUri) Unmarshal(s string) error {
-	uriRegex := `^(?P<Driver>[a-z]+)(\+(?P<Transport>[a-z]+))?://(((?P<Username>[a-z_][-a-z0-9_]*\$?)@)?(?P<Hostname>[-_.a-z0-9]+)(:(?P<Port>[0-9]+)?)?)?(?P<Path>/[-_.a-z0-9]+)?(\?(?P<extra>.*))?$`
+	uriRegex := `^(?P<Driver>[a-z]+)(\+(?P<Transport>[a-z]+))?://(((?P<Username>[a-z_][-a-z0-9_\.]*\$?)@)?(?P<Hostname>[-_.a-z0-9]+)(:(?P<Port>[0-9]+)?)?)?(?P<Path>/[-_.a-z0-9]+)?(\?(?P<extra>.*))?$`
 	re := regexp.MustCompile(uriRegex)
 
 	matches := allMatchedRegexpGroups(re, s)

libvirt-utils/ssh_dialer.go

@@ -9,6 +9,7 @@ import (
 	"github.com/hashicorp/packer-plugin-sdk/pathing"
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/crypto/ssh/knownhosts"
+	"golang.org/x/crypto/ssh/agent"
 )
 
 type SshDialer struct {
@@ -89,31 +90,45 @@ func sshSetAddress(uri LibvirtUri, dialer *SshDialer) error {
 }
 
 func sshDialerSetPrivateKey(uri LibvirtUri, dialer *SshDialer) (err error) {
-
-	keyPath, ok := uri.GetExtra(LibvirtUriParam_Keyfile)
-	if !ok {
-		return fmt.Errorf("ssh transport requires %s parameter", LibvirtUriParam_Keyfile)
-	}
-
-	expandedKeyPath, err := pathing.ExpandUser(keyPath)
-
+	sock, err := net.Dial("unix", os.Getenv("SSH_AUTH_SOCK"))
 	if err != nil {
 		return err
 	}
 
-	key, err := ioutil.ReadFile(expandedKeyPath)
+	agent := agent.NewClient(sock)
 
+	signers, err := agent.Signers()
 	if err != nil {
 		return err
 	}
 
-	parsedKey, err := ssh.ParsePrivateKey(key)
+	auths := []ssh.AuthMethod{ssh.PublicKeys(signers...)}
 
-	if err != nil {
-		return err
-	}
+	dialer.sshConfig.Auth = append(dialer.sshConfig.Auth, auths...)
+
+	keyPath, ok := uri.GetExtra(LibvirtUriParam_Keyfile)
+	if ok {
+		expandedKeyPath, err := pathing.ExpandUser(keyPath)
 
-	dialer.sshConfig.Auth = append(dialer.sshConfig.Auth, ssh.PublicKeys(parsedKey))
+		if err != nil {
+			return err
+		}
+
+		key, err := ioutil.ReadFile(expandedKeyPath)
+
+		if err != nil {
+			return err
+		}
+
+		parsedKey, err := ssh.ParsePrivateKey(key)
+
+		if err != nil {
+			return err
+		}
+
+		dialer.sshConfig.Auth = append(dialer.sshConfig.Auth, ssh.PublicKeys(parsedKey))
+
+	}
 
 	return
 }