test(coverage): unit-cover firecracker cleanup, delegates, and helpers

Cleanup orphan-enumeration + removal, the backend setup/status/teardown/ cleanup classmethod delegates, guest-IP parsing, the unprivileged nft/TAP probes, console-tail, and require_firecracker preflight branches. Lifts the unit-only diff-coverage on the firecracker backend substantially; the deep VM boot/SSH orchestration remains integration-covered. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WBMWTEtQdJ4W5UrWuLHCck
2026-07-11 19:32:57 -04:00
parent 8941b92e37
commit 568cf4f35a
2 changed files with 275 additions and 0 deletions
@@ -0,0 +1,117 @@
+"""Unit: small Firecracker helpers — guest-IP parsing, the unprivileged
+nft/TAP probes, console-tail, and the require_firecracker preflight
+branches. Mock subprocess/os so nothing needs KVM or a live VM.
+"""
+
+from __future__ import annotations
+
+import json
+import subprocess
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+from bot_bottle.backend.firecracker import firecracker_vm, freezer, netpool, util
+
+
+class TestGuestIpFromConfig(unittest.TestCase):
+    def _write(self, obj: object) -> Path:
+        d = tempfile.mkdtemp(prefix="fc-cfg.")
+        p = Path(d) / "config.json"
+        p.write_text(json.dumps(obj))
+        self.addCleanup(lambda: p.unlink(missing_ok=True))
+        return p
+
+    def test_extracts_guest_ip(self):
+        cfg = {"boot-source": {"boot_args":
+               "console=ttyS0 ip=10.243.0.1::10.243.0.0:255.255.255.254::eth0:off"}}
+        self.assertEqual("10.243.0.1", freezer._guest_ip_from_config(self._write(cfg)))
+
+    def test_no_ip_token(self):
+        self.assertEqual("", freezer._guest_ip_from_config(
+            self._write({"boot-source": {"boot_args": "console=ttyS0"}})))
+
+    def test_missing_file(self):
+        self.assertEqual("", freezer._guest_ip_from_config(Path("/nope/config.json")))
+
+    def test_malformed_json(self):
+        d = tempfile.mkdtemp(prefix="fc-cfg.")
+        p = Path(d) / "config.json"
+        p.write_text("{not json")
+        self.addCleanup(lambda: p.unlink(missing_ok=True))
+        self.assertEqual("", freezer._guest_ip_from_config(p))
+
+
+class TestNetpoolProbes(unittest.TestCase):
+    def test_run_ok_true_on_zero(self):
+        with patch.object(netpool.subprocess, "run",
+                          return_value=subprocess.CompletedProcess([], 0)):
+            self.assertTrue(netpool._run_ok(["true"]))
+
+    def test_run_ok_false_on_missing_binary(self):
+        with patch.object(netpool.subprocess, "run", side_effect=FileNotFoundError):
+            self.assertFalse(netpool._run_ok(["nft"]))
+
+    def test_tap_and_nft_probes(self):
+        with patch.object(netpool, "_run_ok", return_value=True) as ok:
+            self.assertTrue(netpool.tap_present("bbfc0"))
+            self.assertTrue(netpool.nft_table_present())
+        self.assertEqual(2, ok.call_count)
+
+    def test_missing_taps(self):
+        with patch.dict("os.environ", {"BOT_BOTTLE_FC_POOL_SIZE": "2"}), \
+             patch.object(netpool, "tap_present", side_effect=[True, False]):
+            self.assertEqual(["bbfc1"], netpool.missing_taps())
+
+
+class TestConsoleTail(unittest.TestCase):
+    def test_reads_tail(self):
+        d = tempfile.mkdtemp(prefix="fc-con.")
+        p = Path(d) / "console.log"
+        p.write_text("l1\nl2\nl3\n")
+        self.addCleanup(lambda: p.unlink(missing_ok=True))
+        out = firecracker_vm._console_tail(p, lines=2)
+        self.assertIn("l2", out)
+        self.assertIn("l3", out)
+        self.assertNotIn("l1", out)
+
+    def test_missing_file(self):
+        self.assertIn("no console log",
+                      firecracker_vm._console_tail(Path("/nope/console.log")))
+
+
+class TestRequireFirecracker(unittest.TestCase):
+    def _die(self):
+        return patch.object(util, "die", side_effect=SystemExit("die"))
+
+    def test_dies_when_not_linux(self):
+        with patch.object(util, "is_linux", return_value=False), self._die():
+            with self.assertRaises(SystemExit):
+                util.require_firecracker()
+
+    def test_dies_when_binary_missing(self):
+        with patch.object(util, "is_linux", return_value=True), \
+             patch.object(util.shutil, "which", return_value=None), \
+             patch.object(util, "info"), self._die():
+            with self.assertRaises(SystemExit):
+                util.require_firecracker()
+
+    def test_dies_when_kvm_missing(self):
+        with patch.object(util, "is_linux", return_value=True), \
+             patch.object(util.shutil, "which", return_value="/usr/bin/firecracker"), \
+             patch.object(util.os.path, "exists", return_value=False), self._die():
+            with self.assertRaises(SystemExit):
+                util.require_firecracker()
+
+    def test_dies_when_kernel_missing(self):
+        with patch.object(util, "is_linux", return_value=True), \
+             patch.object(util.shutil, "which", return_value="/usr/bin/firecracker"), \
+             patch.object(util, "_require_kvm", lambda: None), \
+             patch.object(util.Path, "is_file", return_value=False), self._die():
+            with self.assertRaises(SystemExit):
+                util.require_firecracker()
+
+
+if __name__ == "__main__":
+    unittest.main()