R-880: build-step-bundle.py — the transition bundle for a release whose bundle adds paths (an installed felhom-os-apply refuses unknown paths, R16)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

configs/test_felhom_config_bundle.py

@@ -667,5 +667,67 @@ class SelfupdateWrapperConfinement(unittest.TestCase):
         self.assertEqual(p.returncode, 1, p.stderr)
         self.assertIn("outside /var/lib/felhom-os-apply/agent-update", p.stderr)
 
+
+_sb = importlib.machinery.SourceFileLoader("stepbuild", str(REPO / "scripts" / "build-step-bundle.py"))
+_ss = importlib.util.spec_from_loader("stepbuild", _sb)
+stepbuild = importlib.util.module_from_spec(_ss)
+_sb.exec_module(stepbuild)
+NEW_IN_0146 = {"/usr/local/sbin/felhom-priv-apply", "/var/lib/vz/snippets/felhom-guest-hook.sh",
+               "/usr/local/sbin/felhom-shared-parent.sh", "/etc/systemd/system/felhom-shared-parent.service"}
+
+
+class StepBundle(unittest.TestCase):
+    """R-880 (agent v0.146.1): an INSTALLED wrapper checks an incoming bundle's paths against its OWN table (R16), so a
+    release that adds paths needs a step bundle: the boxes' current bundle with only felhom-os-apply replaced.
+    RED-PROOF: deliver the full bundle to the old table → R16 (test_the_full_bundle_is_refused_by_an_old_table)."""
+
+    def old_world(self):
+        """The base bundle an older wrapper (no R-861 paths) installed, and that wrapper's table."""
+        full = json.loads(builder.build("0.145.0"))
+        full["files"] = [e for e in full["files"] if e["path"] not in NEW_IN_0146]
+        old_wrapper = b'# the v0.145.0 wrapper stands in here\nBUNDLE_OP = "agent_config_update"\n'
+        for e in full["files"]:
+            if e["path"] == "/usr/local/sbin/felhom-os-apply":
+                e["content_b64"], e["sha256"] = base64.b64encode(old_wrapper).decode(), hashlib.sha256(old_wrapper).hexdigest()
+        base = (json.dumps(full, indent=1, sort_keys=True) + "\n").encode()
+        old_dests = {k: v for k, v in osapply.BUNDLE_DESTS.items() if k not in NEW_IN_0146}
+        return base, old_dests
+
+    def parse_with_table(self, data, dests, version):
+        saved = osapply.BUNDLE_DESTS
+        osapply.BUNDLE_DESTS = dests
+        try:
+            return osapply.Bundle(osapply.Apply(Box(b"{}", None), "")).parse(data, hashlib.sha256(data).hexdigest(), version)
+        finally:
+            osapply.BUNDLE_DESTS = saved
+
+    def test_the_full_bundle_is_refused_by_an_old_table(self):
+        _, old_dests = self.old_world()
+        full = builder.build("0.146.1")
+        with self.assertRaises(osapply.Refused) as cm:
+            self.parse_with_table(full, old_dests, "0.146.1")
+        self.assertEqual(cm.exception.code, "R16")
+
+    def test_the_step_bundle_is_accepted_by_the_old_table_and_changes_only_the_wrapper(self):
+        base, old_dests = self.old_world()
+        new_wrapper = (HERE / "felhom-os-apply").read_bytes()
+        step = stepbuild.build_step(base, "0.146.1-step1", new_wrapper)
+        ver, files = self.parse_with_table(step, old_dests, "0.146.1-step1")
+        self.assertEqual(ver, "0.146.1-step1")
+        b, s_ = json.loads(base), json.loads(step)
+        self.assertEqual(sorted(e["path"] for e in b["files"]), sorted(e["path"] for e in s_["files"]), "the paths must not change")
+        changed = [e["path"] for e, f in zip(sorted(b["files"], key=lambda x: x["path"]), sorted(s_["files"], key=lambda x: x["path"]))
+                   if e != f]
+        self.assertEqual(changed, ["/usr/local/sbin/felhom-os-apply"], "exactly the wrapper changes")
+        installed = dict((d, c) for d, c, *_ in files)
+        self.assertEqual(installed["/usr/local/sbin/felhom-os-apply"], new_wrapper)
+        # and the NEW wrapper (now installed) knows every path the release's full bundle names
+        self.assertTrue({e["path"] for e in json.loads(builder.build("0.146.1"))["files"]} <= set(osapply.BUNDLE_DESTS))
+
+    def test_a_step_version_must_carry_a_suffix(self):
+        base, _ = self.old_world()
+        with self.assertRaises(SystemExit):
+            stepbuild.build_step(base, "0.146.1", b"x")
+
 if __name__ == "__main__":
     unittest.main()