Allow registry to be configured at build time

This adds a new `buildinfo` variable `ImageRegistry` that can set at
build time like the `Version` variable. This allows us to customise the
Velero binary to use different registries.

If the variable is set, this variable wille be used when creating the
URIs for both the main `velero` and `velero-restic-restore-helper`
images. If it is not set, default to using Dockerhub (`velero/velero`,
`velero/velero-restic-restore-helper`).

There are numerous ways in which the Velero binary can be built so all
of them have been updated to add the new link time flag to set the
variable:
* `make local` (used for local developer builds to build for the local
  OS and ARCH)
* `make build` (used by developers and also VMware internal builds to
  build a specific OS and ARCH)
* Goreleaser config (used when creating OSS release binaries)
* Dockerfile (used to build the Velero binary used within the image)

All of these workflows are currently triggered from our Makefile where
the variable `REGISTRY` is already available with the default value of
`velero` and used to build the image tag. Where the new `ImageRegistry`
build variable is needed, we pass through this Makefile variable to
those tasks so it can be used accordingly.

The GitHub action and the `./hack/docker-push.sh` script used to push
container images has not been modified. This will continue to use the
default registry specified in the Makefile and will not explicitly pass
it in.

Signed-off-by: Bridget McErlean <bmcerlean@vmware.com>

pkg/install/daemonset.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2018, 2019, 2020 the Velero contributors.
+Copyright the Velero contributors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -23,11 +23,13 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"github.com/vmware-tanzu/velero/internal/velero"
 )
 
 func DaemonSet(namespace string, opts ...podTemplateOption) *appsv1.DaemonSet {
 	c := &podTemplateConfig{
-		image: DefaultImage,
+		image: velero.DefaultVeleroImage(),
 	}
 
 	for _, opt := range opts {

pkg/install/deployment.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2020 the Velero contributors.
+Copyright the Velero contributors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
+	"github.com/vmware-tanzu/velero/internal/velero"
 	"github.com/vmware-tanzu/velero/pkg/builder"
 )
 
@@ -117,7 +118,7 @@ func WithDefaultVolumesToRestic() podTemplateOption {
 func Deployment(namespace string, opts ...podTemplateOption) *appsv1.Deployment {
 	// TODO: Add support for server args
 	c := &podTemplateConfig{
-		image: DefaultImage,
+		image: velero.DefaultVeleroImage(),
 	}
 
 	for _, opt := range opts {

pkg/install/resources.go

@@ -29,20 +29,9 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 
 	"github.com/vmware-tanzu/velero/config/crd/crds"
-	"github.com/vmware-tanzu/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               = "velero/velero:" + imageVersion()
 	DefaultVeleroPodCPURequest = "500m"
 	DefaultVeleroPodMemRequest = "128Mi"
 	DefaultVeleroPodCPULimit   = "1000m"