Avoid crash on wrong output of systemctl version (bsc#1229539)

* Better handling output of systemctl --version

* Add more cases to test grains.core._systemd

salt/grains/core.py

@@ -2432,10 +2432,31 @@ def _systemd():
     """
     Return the systemd grain
     """
-    systemd_info = __salt__["cmd.run"]("systemctl --version").splitlines()
+    systemd_version = "UNDEFINED"
+    systemd_features = ""
+    try:
+        systemd_output = __salt__["cmd.run_all"]("systemctl --version")
+    except Exception:  # pylint: disable=broad-except
+        log.error("Exception while executing `systemctl --version`", exc_info=True)
+        return {
+            "version": systemd_version,
+            "features": systemd_features,
+        }
+    if systemd_output.get("retcode") == 0:
+        systemd_info = systemd_output.get("stdout", "").splitlines()
+        try:
+            if systemd_info[0].startswith("systemd "):
+                systemd_version = systemd_info[0].split()[1]
+                systemd_features = systemd_info[1]
+        except IndexError:
+            pass
+    if systemd_version == "UNDEFINED" or systemd_features == "":
+        log.error(
+            "Unexpected output returned by `systemctl --version`: %s", systemd_output
+        )
     return {
-        "version": systemd_info[0].split()[1],
-        "features": systemd_info[1],
+        "version": systemd_version,
+        "features": systemd_features,
     }
 
 

tests/pytests/unit/grains/test_core.py

@@ -3593,3 +3593,92 @@ def _mock_is_file(filename):
 
         assert virtual_grains["virtual"] == "Nitro"
         assert virtual_grains["virtual_subtype"] == "Amazon EC2"
+
+
+@pytest.mark.parametrize(
+    "systemd_data,expected",
+    (
+        (
+            {
+                "pid": 1234,
+                "retcode": 0,
+                "stdout": "systemd 254 (254.3-1)\n+PAM +AUDIT -SELINUX -APPARMOR -IMA +SMACK "
+                "+SECCOMP +GCRYPT +GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS "
+                "+FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 "
+                "-PWQUALITY +P11KIT -QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD "
+                "+BPF_FRAMEWORK +XKBCOMMON +UTMP -SYSVINIT default-hierarchy=unified",
+                "stderr": "",
+            },
+            {
+                "version": "254",
+                "features": "+PAM +AUDIT -SELINUX -APPARMOR -IMA +SMACK +SECCOMP +GCRYPT +GNUTLS +OPENSSL "
+                "+ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP "
+                "+LIBFDISK +PCRE2 -PWQUALITY +P11KIT -QRENCODE +TPM2 +BZIP2 +LZ4 +XZ "
+                "+ZLIB +ZSTD +BPF_FRAMEWORK +XKBCOMMON +UTMP -SYSVINIT default-hierarchy=unified",
+            },
+        ),
+        (
+            {
+                "pid": 2345,
+                "retcode": 1,
+                "stdout": "",
+                "stderr": "some garbage in the output",
+            },
+            {
+                "version": "UNDEFINED",
+                "features": "",
+            },
+        ),
+        (
+            {
+                "pid": 3456,
+                "retcode": 0,
+                "stdout": "unexpected stdout\none more line",
+                "stderr": "",
+            },
+            {
+                "version": "UNDEFINED",
+                "features": "",
+            },
+        ),
+        (
+            {
+                "pid": 4567,
+                "retcode": 0,
+                "stdout": "",
+                "stderr": "",
+            },
+            {
+                "version": "UNDEFINED",
+                "features": "",
+            },
+        ),
+        (
+            Exception("Some exception on calling `systemctl --version`"),
+            {
+                "version": "UNDEFINED",
+                "features": "",
+            },
+        ),
+    ),
+)
+def test__systemd(systemd_data, expected):
+    """
+    test _systemd
+    """
+
+    def mock_run_all_systemd(_):
+        if isinstance(systemd_data, Exception):
+            raise systemd_data
+        return systemd_data
+
+    with patch.dict(
+        core.__salt__,
+        {
+            "cmd.run_all": mock_run_all_systemd,
+        },
+    ):
+        ret = core._systemd()
+        assert "version" in ret
+        assert "features" in ret
+        assert ret == expected