Use latest container image when version is empty (#1439)

When using `velero install`, the image used should be a reasonable
default, even if buildinfo.Version is missing (such as when using `go
build` directly).

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

changelogs/unreleased/1439-nrb

@@ -0,0 +1 @@
+Use `latest` image tag if no version information is provided at build time

pkg/install/deployment.go

@@ -70,7 +70,7 @@ func WithRestoreOnly() podTemplateOption {
 func Deployment(namespace string, opts ...podTemplateOption) *appsv1beta1.Deployment {
 	// TODO: Add support for server args
 	c := &podTemplateConfig{
-		image: "gcr.io/heptio-images/velero:latest",
+		image: DefaultImage,
 	}
 
 	for _, opt := range opts {

pkg/install/resources.go

@@ -28,8 +28,16 @@ import (
 	"github.com/heptio/velero/pkg/buildinfo"
 )
 
+// Use "latest" if the build process didn't supply a version
+func imageVersion() string {
+	if buildinfo.Version == "" {
+		return "latest"
+	}
+	return buildinfo.Version
+}
+
 // DefaultImage is the default image to use for the Velero deployment and restic daemonset containers.
-var DefaultImage = "gcr.io/heptio-images/velero:" + buildinfo.Version
+var DefaultImage = "gcr.io/heptio-images/velero:" + imageVersion()
 
 func labels() map[string]string {
 	return map[string]string{