Tools: fetch image test case generation matrix from composer

Add a simple tool `osbuild-composer-image-definitions` which dumps the
matrix of all distributions, architectures and image types names
supported by composer as a JSON to the stdout.

Default to fetching the image test case generation matrix directly from
composer. This eliminates the need to update a JSON source file with
this information every time a new distro or image type are added to
composer.

Delete the previously used JSON source file with the image test case
generation matrix.

Signed-off-by: Tomas Hozza <thozza@redhat.com>

cmd/osbuild-composer-image-definitions/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/osbuild/osbuild-composer/internal/distroregistry"
+)
+
+func main() {
+	definitions := map[string]map[string][]string{}
+	distroRegistry := distroregistry.NewDefault()
+
+	for _, distroName := range distroRegistry.List() {
+		distro := distroRegistry.GetDistro(distroName)
+		for _, archName := range distro.ListArches() {
+			arch, err := distro.GetArch(archName)
+			if err != nil {
+				panic(fmt.Sprintf("failed to get arch %q of distro %q listed in aches list", archName, distroName))
+			}
+			_, ok := definitions[distroName]
+			if !ok {
+				definitions[distroName] = map[string][]string{}
+			}
+			definitions[distroName][archName] = arch.ListImageTypes()
+		}
+	}
+
+	encoder := json.NewEncoder(os.Stdout)
+	err := encoder.Encode(definitions)
+	if err != nil {
+		panic(err)
+	}
+}