napalm_linux/linux.py

@@ -50,6 +50,12 @@ logger = logging.getLogger("napalm_linux")
 # Package managers in detection order
 _PKG_MANAGERS = ["apt", "dnf", "yum", "apk", "pacman"]
 
+#: Printed after a command by ``_sudo_status`` so its exit status survives the
+#: trip through an interactive shell. Matched only on a line of its own with a
+#: number after it — an echoed command line carries the literal ``$?`` instead.
+_RC_MARKER = "__NETORK_RC="
+_RC_MARKER_RE = re.compile(rf"^{_RC_MARKER}(\d+)\s*$", re.MULTILINE)
+
 # DMI field values that carry no useful information (OEM defaults, blanks)
 _BAD_DMI: frozenset[str] = frozenset({
     "", "none", "n/a", "not specified", "not applicable",
@@ -267,6 +273,25 @@ class LinuxDriver(OSDriver):
             return self._send(wrapped, read_timeout=read_timeout)
         return self._send(f'sudo {command}', read_timeout=read_timeout)
 
+    def _sudo_status(self, command: str, read_timeout: float = 100) -> tuple[str, int | None]:
+        """Run *command* via sudo and return ``(output, exit_status)``.
+
+        ``_sudo`` callers append ``|| true`` so a failing command yields output
+        instead of an error, which throws the exit status away. This variant
+        echoes ``$?`` straight after the sudo pipeline instead — sudo passes
+        the command's status through, and a failed password is non-zero too.
+
+        The status is ``None`` when the marker never arrived (output cut short),
+        so a caller can tell "unknown" from "succeeded".
+        """
+        raw = self._sudo(f"{command}; echo {_RC_MARKER}$?", read_timeout=read_timeout)
+        matches = list(_RC_MARKER_RE.finditer(raw))
+        if not matches:
+            return raw, None
+        last = matches[-1]
+        output = (raw[: last.start()] + raw[last.end():]).strip()
+        return output, int(last.group(1))
+
     def _detect_pkg_manager(self) -> str | None:
         """Return the first package manager binary found on PATH."""
         for pm in _PKG_MANAGERS:
@@ -1046,6 +1071,7 @@ class LinuxDriver(OSDriver):
         return {"success": success, "output": raw.strip()}
 
     #: Words in a package manager's output that mean it did not do the job.
+    #: Only consulted when the exit status is unknown; see ``_uninstall_failed``.
     _UNINSTALL_FAILED = ("error:", "failed", "not found", "is not installed", "no packages")
 
     def uninstall_package(self, name: str, purge: bool = False) -> dict[str, Any]:
@@ -1077,42 +1103,49 @@ class LinuxDriver(OSDriver):
         pm = self._pkg_manager
         if pm == "apt":
             action = "purge" if purge else "remove"
-            raw = self._sudo(
+            cmd = f"DEBIAN_FRONTEND=noninteractive apt-get {action} -y {safe} 2>&1"
-                f"DEBIAN_FRONTEND=noninteractive apt-get {action} -y {safe} 2>&1 || true"
-            )
         elif pm in ("dnf", "yum"):
-            raw = self._sudo(f"{pm} remove -y {safe} 2>&1 || true")
+            cmd = f"{pm} remove -y {safe} 2>&1"
         elif pm == "apk":
             # apk and pacman have no separate purge; asking for one is not an
             # error, it simply has nothing extra to do.
-            raw = self._sudo(f"apk del {safe} 2>&1 || true")
+            cmd = f"apk del {safe} 2>&1"
         elif pm == "pacman":
-            raw = self._sudo(f"pacman -R --noconfirm {safe} 2>&1 || true")
+            cmd = f"pacman -R --noconfirm {safe} 2>&1"
         else:
             return {"success": False, "output": f"Unsupported package manager: {pm}"}
 
-        if self._uninstall_failed(raw) and pm == "apt":
+        raw, rc = self._sudo_status(cmd)
-            forced = self._sudo(f"dpkg --purge --force-all {safe} 2>&1 || true")
+        failed = self._uninstall_failed(raw, rc)
-            if not self._uninstall_failed(forced):
+
-                return {
+        if failed and pm == "apt":
-                    "success": True,
+            forced, forced_rc = self._sudo_status(f"dpkg --purge --force-all {safe} 2>&1")
-                    "output": f"{raw.strip()}\n--- dpkg --purge --force-all ---\n{forced.strip()}",
-                }
             raw = f"{raw.strip()}\n--- dpkg --purge --force-all ---\n{forced.strip()}"
+            failed = self._uninstall_failed(forced, forced_rc)
 
-        return {"success": not self._uninstall_failed(raw), "output": raw.strip()}
+        return {"success": not failed, "output": raw.strip()}
 
-    def _uninstall_failed(self, output: str) -> bool:
+    def _uninstall_failed(self, output: str, rc: int | None = None) -> bool:
-        """Whether the package manager said it did not do the job.
+        """Whether the package manager did not do the job.
 
-        apt prefixes its own errors with ``E: `` at the start of a line, and
+        The exit status decides whenever there is one (netork#267): it is the
-        the commonest of them — ``E: Sub-process /usr/bin/dpkg returned an
+        answer the package manager actually gives, where the output is prose
-        error code (1)`` — contains neither "error:" nor "failed". The keyword
+        that every tool phrases differently. A prerm printing "Failed to stop
-        list alone therefore read a failed removal as a success, which is the
+        …" while the removal completes is a success; a non-zero exit with
-        worst direction for this particular answer to be wrong in.
+        nothing alarming in the output is not.
+
+        Only when the status is unknown (``rc is None``) is the output read,
+        as the best answer left. apt prefixes its own errors with ``E: `` at
+        the start of a line, and the commonest of them — ``E: Sub-process
+        /usr/bin/dpkg returned an error code (1)`` — contains neither "error:"
+        nor "failed". The keyword list alone therefore read a failed removal
+        as a success, which is the worst direction for this particular answer
+        to be wrong in.
 
         Matched at line start rather than anywhere: "note: " ends in "e: ".
         """
+        if rc is not None:
+            return rc != 0
         low = output.lower()
         if any(line.lstrip().startswith("e: ") for line in low.splitlines()):
             return True

tests/test_linux.py

@@ -984,3 +984,164 @@ class TestUninstallPackage:
 
         assert result["success"] is True
         assert "apk del" in driver._device.send_command.call_args[0][0]
+
+
+# ---------------------------------------------------------------------------
+# uninstall_package – success from the exit status, not from prose (netork#267)
+# ---------------------------------------------------------------------------
+
+
+def _with_rc(output: str, rc: int) -> str:
+    """What the shell prints for a command run through ``_sudo_status``."""
+    return f"{output}\n__NETORK_RC={rc}"
+
+
+class TestSudoStatus:
+    """``_sudo_status`` keeps the exit status that ``|| true`` throws away."""
+
+    def test_returns_output_and_exit_status(self, driver):
+        _mock_send(driver, _with_rc("Removing wazuh-agent ...", 0))
+
+        assert driver._sudo_status("apt-get remove -y wazuh-agent") == (
+            "Removing wazuh-agent ...",
+            0,
+        )
+
+    def test_a_non_zero_exit_status_is_reported(self, driver):
+        _mock_send(driver, _with_rc("E: Unable to locate package nope", 100))
+
+        assert driver._sudo_status("apt-get remove -y nope")[1] == 100
+
+    def test_the_status_is_read_right_after_sudo_returns(self, driver):
+        """``$?`` must be read straight after the sudo pipeline — with an
+        ``|| true`` in between, every command would report 0."""
+        driver._sudo_password = "pw"  # noqa: S105
+        _mock_send(driver, _with_rc("", 0))
+
+        driver._sudo_status("apt-get remove -y x 2>&1")
+
+        sent = driver._device.send_command.call_args[0][0]
+        assert sent.startswith("echo pw | sudo -S")
+        assert sent.endswith("apt-get remove -y x 2>&1; echo __NETORK_RC=$?")
+        assert "|| true" not in sent
+
+    def test_a_missing_marker_means_unknown_not_success(self, driver):
+        """Output cut short before the marker arrived says nothing about the
+        exit status; ``None`` says so instead of guessing 0."""
+        _mock_send(driver, "Removing wazuh-agent ...")
+
+        assert driver._sudo_status("apt-get remove -y wazuh-agent") == (
+            "Removing wazuh-agent ...",
+            None,
+        )
+
+    def test_the_command_echo_is_not_mistaken_for_the_marker(self, driver):
+        """A terminal may echo the command line back; its literal ``$?`` is not
+        a number, and only the marker on a line of its own counts."""
+        _mock_send(
+            driver,
+            "sudo apt-get remove -y x; echo __NETORK_RC=$?\nRemoving x ...\n__NETORK_RC=1",
+        )
+
+        output, rc = driver._sudo_status("apt-get remove -y x")
+
+        assert rc == 1
+        assert "__NETORK_RC=1" not in output
+
+
+class TestUninstallExitStatus:
+    """Whether a removal worked is what the package manager's exit status says.
+
+    Reading it out of human-readable output was guesswork in both directions:
+    apt's commonest failure (``E: Sub-process /usr/bin/dpkg returned an error
+    code (1)``) read as success until #240, and a successful removal whose
+    prerm merely *mentions* a failure read as a failure.
+    """
+
+    def test_a_non_zero_exit_is_a_failure_whatever_the_output_says(self, driver):
+        """Nothing in this output matches a failure keyword; only the exit
+        status knows."""
+        driver._pkg_manager = "dnf"
+        _mock_send(driver, _with_rc("Removing: wazuh-agent", 1))
+
+        result = driver.uninstall_package("wazuh-agent")
+
+        assert result["success"] is False
+
+    def test_a_zero_exit_is_a_success_even_if_the_output_mentions_failure(self, driver):
+        """A prerm that cannot stop an already-dead unit prints "Failed" and
+        still lets the removal complete."""
+        _mock_send(
+            driver,
+            _with_rc(
+                "Removing wazuh-agent (4.14.7-1) ...\n"
+                "Failed to stop wazuh-agent.service: Unit wazuh-agent.service not loaded.",
+                0,
+            ),
+        )
+
+        result = driver.uninstall_package("wazuh-agent")
+
+        assert result["success"] is True
+
+    def test_the_marker_does_not_reach_the_caller(self, driver):
+        _mock_send(driver, _with_rc("Removing wazuh-agent ...", 0))
+
+        result = driver.uninstall_package("wazuh-agent")
+
+        assert result["output"] == "Removing wazuh-agent ..."
+
+    def test_the_uninstall_command_keeps_its_exit_status(self, driver):
+        _mock_send(driver, _with_rc("Removing wazuh-agent ...", 0))
+
+        driver.uninstall_package("wazuh-agent")
+
+        sent = driver._device.send_command.call_args[0][0]
+        assert "|| true" not in sent
+        assert sent.endswith("; echo __NETORK_RC=$?")
+
+    def test_apt_failing_by_exit_status_falls_back_to_dpkg(self, driver):
+        driver._device.send_command.side_effect = [
+            _with_rc("E: Sub-process /usr/bin/dpkg returned an error code (1)", 100),
+            _with_rc("Removing wazuh-agent (4.14.7-1) ...", 0),
+        ]
+
+        result = driver.uninstall_package("wazuh-agent", purge=True)
+
+        assert result["success"] is True
+        second = driver._device.send_command.call_args_list[1][0][0]
+        assert "dpkg --purge --force-all" in second
+        assert "|| true" not in second
+        assert "__NETORK_RC" not in result["output"]
+
+    def test_the_dpkg_fallback_failing_is_a_failure(self, driver):
+        driver._device.send_command.side_effect = [
+            _with_rc("E: Sub-process /usr/bin/dpkg returned an error code (1)", 100),
+            _with_rc("dpkg: error processing package wazuh-agent (--purge):", 1),
+        ]
+
+        result = driver.uninstall_package("wazuh-agent", purge=True)
+
+        assert result["success"] is False
+        assert "dpkg --purge --force-all" in result["output"]
+
+    def test_a_zero_exit_does_not_trigger_the_fallback(self, driver):
+        """Even when the output contains words that used to mean failure: apt
+        exits 0 for a package that is already gone, which is the state the
+        caller asked for."""
+        _mock_send(driver, _with_rc("Package 'x' is not installed, so not removed", 0))
+
+        result = driver.uninstall_package("x", purge=True)
+
+        assert result["success"] is True
+        assert driver._device.send_command.call_count == 1
+
+    def test_without_an_exit_status_the_output_is_read_as_before(self, driver):
+        """If the marker never arrived, the keyword check is still the best
+        answer available — and it errs towards failure on apt's ``E:``."""
+        driver._pkg_manager = "dnf"
+        _mock_send(driver, "E: Sub-process /usr/bin/dpkg returned an error code (1)")
+
+        result = driver.uninstall_package("wazuh-agent")
+
+        assert result["success"] is False