Allow only creating unified ISO for specified arch

Fixes: https://pagure.io/pungi/issue/1393
JIRA: RHELCMP-807
Signed-off-by: Haibo Lin <hlin@redhat.com>

pungi/scripts/create_unified_isos.py

@@ -18,11 +18,18 @@ def parse_args():
     parser.add_argument(
         "compose", metavar="<compose-path>", nargs=1, help="path to compose",
     )
+    parser.add_argument(
+        "--arch",
+        metavar="<arch>",
+        dest="arches",
+        action="append",
+        help="only generate ISOs for specified arch",
+    )
 
     return parser.parse_args()
 
 
 def main():
     args = parse_args()
-    iso = UnifiedISO(args.compose[0])
+    iso = UnifiedISO(args.compose[0], arches=args.arches)
     iso.create(delete_temp=True)

pungi_utils/unified_isos.py

@@ -63,7 +63,7 @@ DEFAULT_CHECKSUMS = ["md5", "sha1", "sha256"]
 
 
 class UnifiedISO(object):
-    def __init__(self, compose_path, output_path=None):
+    def __init__(self, compose_path, output_path=None, arches=None):
         self.compose_path = os.path.abspath(compose_path)
         compose_subdir = os.path.join(self.compose_path, "compose")
         if os.path.exists(compose_subdir):
@@ -84,6 +84,7 @@ class UnifiedISO(object):
         self.productid = {}  # {arch/stc: {variant: old_path}
         self.conf = self.read_config()
         self.images = None  # productmd.images.Images instance
+        self.arches = arches
 
     def create(self, delete_temp=True):
         print("Creating unified ISOs for: {0}".format(self.compose_path))
@@ -161,6 +162,8 @@ class UnifiedISO(object):
         # copy files to new location; change RPM location to $variant_uid
         for variant in self.ci.get_variants(recursive=False):
             for arch in variant.arches:
+                if self.arches and arch not in self.arches:
+                    continue
                 print("Processing: {0}.{1}".format(variant.uid, arch))
                 try:
                     tree_dir = os.path.join(