fus: Strip protocol from repo path

Only local paths are supported currently. As such, `file://` can be
stripped, and for anything else we should raise an exception.

JIRA: COMPOSE-2996
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/wrappers/fus.py

@@ -37,9 +37,9 @@ def get_cmd(
     cmd = ["fus", "--verbose", "--arch", arch]
 
     for idx, repo in enumerate(repos):
-        cmd.append("--repo=repo-%s,repo,%s" % (idx, repo))
+        cmd.append("--repo=repo-%s,repo,%s" % (idx, _prep_path(repo)))
     for idx, repo in enumerate(lookasides):
-        cmd.append("--repo=lookaside-%s,lookaside,%s" % (idx, repo))
+        cmd.append("--repo=lookaside-%s,lookaside,%s" % (idx, _prep_path(repo)))
 
     if platform:
         cmd.append("--platform=%s" % platform)
@@ -52,6 +52,17 @@ def get_cmd(
     return cmd
 
 
+def _prep_path(path):
+    """Strip file:// from the path if present or raise exception for other
+    protocols.
+    """
+    if "://" in path:
+        proto, path = path.split("://", 2)
+        if proto != "file":
+            raise ValueError("Only repositories on local filesystem are supported.")
+    return path
+
+
 def parse_output(output):
     """Read output of fus from the given filepath, and return a set of tuples
     (NVR, arch, flags) and a set of module NSVCs.

tests/test_fus_wrapper.py

@@ -47,6 +47,27 @@ class TestGetCmd(unittest.TestCase):
             ],
         )
 
+    def test_strip_file_protocol(self):
+        cmd = fus.get_cmd("x86_64", ["file:///tmp"], [], [], [], [])
+        self.assertEqual(
+            cmd, ["fus", "--verbose", "--arch", "x86_64", "--repo=repo-0,repo,/tmp"]
+        )
+
+    def test_fail_on_http_repo(self):
+        with self.assertRaises(ValueError):
+            fus.get_cmd("x86_64", ["http:///tmp"], [], [], [], [])
+
+    def test_strip_file_protocol_lookaside(self):
+        cmd = fus.get_cmd("x86_64", [], ["file:///r"], [], [], [])
+        self.assertEqual(
+            cmd,
+            ["fus", "--verbose", "--arch", "x86_64", "--repo=lookaside-0,lookaside,/r"]
+        )
+
+    def test_fail_on_http_repo_lookaside(self):
+        with self.assertRaises(ValueError):
+            fus.get_cmd("x86_64", [], ["http:///tmp"], [], [], [])
+
 
 class TestParseOutput(unittest.TestCase):
     def setUp(self):