assembler: rename qcow2 to qemu and add support for more formats

Opt in to supporting the most common ones, if we want to support more
we can add support as the need arises.

Signed-off-by: Tom Gundersen <teg@jklm.no>

README.md

@@ -43,8 +43,9 @@ assembles it into an image. Pipelines are defined as JSON files like this one:
     }
   ],
   "assembler": {
-    "name": "org.osbuild.qcow2",
+    "name": "org.osbuild.qemu",
     "options": {
+      "format": "qcow2",
       "filename": "example.qcow2",
       "root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
       "size": 3221225472

assemblers/org.osbuild.qemu

@@ -37,6 +37,7 @@ def loop_device(loop_client, image, size, offset=0):
         os.unlink(path)
 
 def main(tree, output_dir, options, loop_client):
+    fmt = options["format"]
     filename = options["filename"]
     root_fs_uuid = options["root_fs_uuid"]
     size = options["size"]
@@ -45,6 +46,9 @@ def main(tree, output_dir, options, loop_client):
     if size % 512 != 0:
         raise ValueError("`size` must be a multiple of sector size (512)")
 
+    if fmt not in ["raw", "qcow2", "vdi", "vmdk"]:
+        raise ValueError("`format` must be one of raw, qcow, vdi, vmdk")
+
     image = f"/var/tmp/osbuild-image.raw"
     mountpoint = f"/tmp/osbuild-mnt"
 
@@ -76,7 +80,7 @@ def main(tree, output_dir, options, loop_client):
             subprocess.run(["chroot", mountpoint, "grub2-install", "--no-floppy",
                             "--modules=part_msdos", "--target=i386-pc", loop_block], check=True)
 
-    subprocess.run(["qemu-img", "convert", "-O", "qcow2", "-c", image, f"{output_dir}/{filename}"], check=True)
+    subprocess.run(["qemu-img", "convert", "-O", fmt, "-c", image, f"{output_dir}/{filename}"], check=True)
 
 if __name__ == '__main__':
     args = json.load(sys.stdin)

samples/base-qcow2.json

@@ -65,8 +65,9 @@
   ],
   "assembler":
     {
-      "name": "org.osbuild.qcow2",
+      "name": "org.osbuild.qemu",
       "options": {
+        "format": "qcow2",
         "filename": "base.qcow2",
         "root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
         "size": 3221225472

test/pipelines/f30-boot.json

@@ -97,8 +97,9 @@
   ],
   "assembler":
     {
-      "name": "org.osbuild.qcow2",
+      "name": "org.osbuild.qemu",
       "options": {
+        "format": "qcow2",
 	"filename": "f30-boot.qcow2",
         "root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
         "size": 3221225472