pkg/utils: Support RHEL 9 Toolbx containers

The URLs for the RHEL Toolbx images based on the Red Hat Universal Base
Images (or UBI) are a bit more complicated to construct, in comparison
to the URLs for Fedora's fedora-toolbox images.  It's not enough to just
concatenate the registry, the image's basename and the release.  Some
parts of the URL depend on the release's major number, which requires
custom code.

So far, the release's major number was hard coded to 8 since only RHEL 8
Toolbx containers were supported.

To support other RHEL major releases, it's necessary to have custom code
to construct the URLs for the Toolbx images.

https://github.com/containers/toolbox/issues/1065

src/pkg/utils/utils.go

@@ -38,15 +38,14 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+type GetFullyQualifiedImageFunc func(string, string) string
 type ParseReleaseFunc func(string) (string, error)
 
 type Distro struct {
 	ContainerNamePrefix    string
 	ImageBasename          string
+	GetFullyQualifiedImage GetFullyQualifiedImageFunc
 	ParseRelease           ParseReleaseFunc
-	Registry               string
-	Repository             string
-	RepositoryNeedsRelease bool
 }
 
 const (
@@ -99,18 +98,14 @@ var (
 		"fedora": {
 			"fedora-toolbox",
 			"fedora-toolbox",
+			getFullyQualifiedImageFedora,
 			parseReleaseFedora,
-			"registry.fedoraproject.org",
-			"",
-			false,
 		},
 		"rhel": {
 			"rhel-toolbox",
 			"toolbox",
+			getFullyQualifiedImageRHEL,
 			parseReleaseRHEL,
-			"registry.access.redhat.com",
-			"ubi8",
-			false,
 		},
 	}
 )
@@ -319,21 +314,8 @@ func GetFullyQualifiedImageFromDistros(image, release string) (string, error) {
 			continue
 		}
 
-		var repository string
-
-		if distroObj.RepositoryNeedsRelease {
-			repository = fmt.Sprintf(distroObj.Repository, release)
-		} else {
-			repository = distroObj.Repository
-		}
-
-		imageFull := distroObj.Registry
-
-		if repository != "" {
-			imageFull = imageFull + "/" + repository
-		}
-
-		imageFull = imageFull + "/" + image
+		getFullyQualifiedImageImpl := distroObj.GetFullyQualifiedImage
+		imageFull := getFullyQualifiedImageImpl(image, release)
 
 		logrus.Debugf("Resolved image %s to %s", image, imageFull)
 
@@ -343,6 +325,23 @@ func GetFullyQualifiedImageFromDistros(image, release string) (string, error) {
 	return "", fmt.Errorf("failed to resolve image %s", image)
 }
 
+func getFullyQualifiedImageFedora(image, release string) string {
+	imageFull := "registry.fedoraproject.org/" + image
+	return imageFull
+}
+
+func getFullyQualifiedImageRHEL(image, release string) string {
+	i := strings.IndexRune(release, '.')
+	if i == -1 {
+		panicMsg := fmt.Sprintf("release %s not in '<major>.<minor>' format", release)
+		panic(panicMsg)
+	}
+
+	releaseMajor := release[:i]
+	imageFull := "registry.access.redhat.com/ubi" + releaseMajor + "/" + image
+	return imageFull
+}
+
 // GetGroupForSudo returns the name of the sudoers group.
 //
 // Some distros call it 'sudo' (eg. Ubuntu) and some call it 'wheel' (eg. Fedora).