distro/rhel84: add centos 8 stream support

The image definition is shared with the latest RHEL 8.y one (8.4 currently).
I expect that we the introduction of 8.5 support, we point the centos 8
distro at it.

The test repositories and manifests use the official CentOS composes. From
what I can tell, they are persistent. This is not guaranteed though, so we
might need to switch to RPMRepo at some point.

The "classic" CentOS 8 should also be buildable but due to the chicken and egg
issue (this commit will get into Centos "8.4" but Centos "8.4" isn't a thing
yet), we cannot test it and therefore it might be broken.

Signed-off-by: Ondřej Budai <ondrej@budai.cz>

cmd/osbuild-composer/composer.go

@@ -63,7 +63,7 @@ func NewComposer(config *ComposerConfigFile, stateDir, cacheDir string, logger *
 		return nil, err
 	}
 
-	c.distros, err = distro.NewRegistry(fedora32.New(), fedora33.New(), rhel8.New(), rhel84.New())
+	c.distros, err = distro.NewRegistry(fedora32.New(), fedora33.New(), rhel8.New(), rhel84.New(), rhel84.NewCentos())
 	if err != nil {
 		return nil, fmt.Errorf("Error loading distros: %v", err)
 	}
@@ -83,7 +83,7 @@ func NewComposer(config *ComposerConfigFile, stateDir, cacheDir string, logger *
 func (c *Composer) InitWeldr(repoPaths []string, weldrListener net.Listener) error {
 	archName := common.CurrentArch()
 
-	hostDistro, beta, err := c.distros.FromHost()
+	hostDistro, beta, isStream, err := c.distros.FromHost()
 	if err != nil {
 		return err
 	}
@@ -102,6 +102,11 @@ func (c *Composer) InitWeldr(repoPaths []string, weldrListener net.Listener) err
 		name += "-beta"
 	}
 
+	// override repository for centos stream, remove when CentOS 8 is EOL
+	if isStream && name == "centos-8" {
+		name = "centos-stream-8"
+	}
+
 	repos, err := rpmmd.LoadRepositories(repoPaths, name)
 	if err != nil {
 		return fmt.Errorf("Error loading repositories for %s: %v", hostDistro.Name(), err)

cmd/osbuild-pipeline/main.go

@@ -73,7 +73,7 @@ func main() {
 		}
 	}
 
-	distros, err := distro.NewRegistry(fedora32.New(), fedora33.New(), rhel8.New(), rhel84.New())
+	distros, err := distro.NewRegistry(fedora32.New(), fedora33.New(), rhel8.New(), rhel84.New(), rhel84.NewCentos())
 	if err != nil {
 		panic(err)
 	}