domain: Add a function to get the qemu package version

This is a more detailed version string than is returned by Version(),
allowing callers to distinguish between patch builds.

Author: adamwg

qemu/domain.go

@@ -346,6 +346,17 @@ func (d *Domain) Version() (string, error) {
 	return response.Return.String(), nil
 }
 
+// PackageVersion returns the domain's QEMU package version, the full build
+// information for QEMU.
+func (d *Domain) PackageVersion() (string, error) {
+	vers, err := d.rm.QueryVersion()
+	if err != nil {
+		return "", err
+	}
+
+	return vers.Package, nil
+}
+
 // Events streams QEMU QMP events.
 // Two channels are returned, the first contains events emitted by the domain.
 // The second is used to signal completion of event processing.

qemu/version_test.go

@@ -18,6 +18,7 @@ import (
 	"testing"
 
 	"github.com/digitalocean/go-qemu/qmp"
+	"github.com/digitalocean/go-qemu/qmp/raw"
 )
 
 func TestVersion(t *testing.T) {
@@ -48,3 +49,33 @@ func TestVersion(t *testing.T) {
 		t.Errorf("expected version %q, instead got %q", expected, v)
 	}
 }
+
+func TestPackageVersion(t *testing.T) {
+	result := raw.VersionInfo{}
+	result.Qemu.Major = 2
+	result.Qemu.Minor = 8
+	result.Qemu.Micro = 0
+	result.Package = "(Debian 1:2.8+dfsg-3ubuntu2.4)"
+
+	d, done := testDomain(t, func(cmd qmp.Command) (interface{}, error) {
+		if want, got := "query-version", cmd.Execute; want != got {
+			t.Fatalf("unexpected QMP command:\n- want: %q\n-  got: %q",
+				want, got)
+		}
+
+		return success{
+			Return: result,
+		}, nil
+	})
+	defer done()
+
+	v, err := d.PackageVersion()
+	if err != nil {
+		t.Error(err)
+	}
+
+	expected := "(Debian 1:2.8+dfsg-3ubuntu2.4)"
+	if v != expected {
+		t.Errorf("expected package version %q, instead got %q", expected, v)
+	}
+}