Add support for selecting the container architecture

dockersave/__init__.py

@@ -55,7 +55,7 @@ def get_token(image, user=None, password=None, auth_endpoint="https://auth.docke
 
     return r.json()['token']
 
-def get_manifest(image, tag, token, registry_url):
+def get_manifest(image, tag, token, registry_url, arch="amd64"):
     request_url = "{}/v2/{}/manifests/{}".format(registry_url, image, tag)
 
     supported_fat_manifests = [
@@ -79,7 +79,12 @@ def get_manifest(image, tag, token, registry_url):
             )
 
     if r.headers["content-type"] in supported_fat_manifests:
-        return get_manifest(image, r.json()['manifests'][0]["digest"], token, registry_url)
+        return get_manifest(
+                image, 
+                next(x['digest'] for x in r.json()['manifests'] if x['platform']['architecture'] == arch), 
+                token, 
+                registry_url
+                )
 
     r.raise_for_status()
     return r
@@ -155,7 +160,7 @@ def lexer_wrapper(string, user=None, password=None, secure=True):
     return img
 
 class Image:
-    def __init__(self, image, tag, user=None, password=None, other_tags=False, registry_url="https://registry-1.docker.io"):
+    def __init__(self, image, tag, user=None, password=None, other_tags=False, registry_url="https://registry-1.docker.io", arch="amd64"):
         self.image = image
         self.tag = tag
         self.registry_url = registry_url
@@ -181,7 +186,7 @@ def __init__(self, image, tag, user=None, password=None, other_tags=False, regis
         else:
             self.taglist = None
 
-        self.manifest_response = get_manifest(image, tag, self.token, self.registry_url)
+        self.manifest_response = get_manifest(image, tag, self.token, self.registry_url, arch)
 
         self.manifest = self.manifest_response.json()
 

dockersave/cli.py

@@ -32,7 +32,9 @@ def download(args):
                 user=args.user, 
                 password=args.password,
                 other_tags=args.tags,
-                registry_url=l['registry_url'])
+                registry_url=l['registry_url'],
+                arch=args.arch
+                )
 
         if args.tags:
             from pprint import PrettyPrinter as pp
@@ -72,6 +74,7 @@ def get_parser():
     parser.add_argument('--metadata', action='store_true')
     parser.add_argument('--sha', action='store_true')
     parser.add_argument('--tags', action='store_true')
+    parser.add_argument('--arch', type=str, default="amd64")
     parser.add_argument('--version', action='version', version=__version__)
     parser.set_defaults(func=download)