Add support for AIX (closes #241)

src/distro/distro.py

@@ -219,6 +219,7 @@ def id() -> str:
     "freebsd"       FreeBSD
     "midnightbsd"   MidnightBSD
     "rocky"         Rocky Linux
+    "aix"           AIX
     ==============  =========================================
 
     If you have a need to get distros for reliable IDs added into this set,
@@ -638,11 +639,12 @@ class LinuxDistribution:
 
     def __init__(
         self,
-        include_lsb: bool = True,
+        include_lsb: Optional[bool] = None,
         os_release_file: str = "",
         distro_release_file: str = "",
-        include_uname: bool = True,
+        include_uname: Optional[bool] = None,
         root_dir: Optional[str] = None,
+        include_oslevel: Optional[bool] = None,
     ) -> None:
         """
         The initialization method of this class gathers information from the
@@ -683,7 +685,13 @@ def __init__(
           be empty.
 
         * ``root_dir`` (string): The absolute path to the root directory to use
-          to find distro-related information files.
+          to find distro-related information files. Note that ``include_*``
+          parameters must not be enabled in combination with ``root_dir``.
+
+        * ``include_oslevel`` (bool): Controls whether (AIX) oslevel command
+          output is included as a data source. If the oslevel command is not
+          available in the program execution path the data source will be
+          empty.
 
         Public instance attributes:
 
@@ -702,15 +710,22 @@ def __init__(
           parameter. This controls whether the uname information will
           be loaded.
 
+        * ``include_oslevel`` (bool): The result of the ``include_oslevel``
+          parameter. This controls whether (AIX) oslevel information will be
+          loaded.
+
+        * ``root_dir`` (string): The result of the ``root_dir`` parameter.
+          The absolute path to the root directory to use to find distro-related
+          information files.
+
         Raises:
 
+        * :py:exc:`ValueError`: Initialization parameters combination is not
+           supported.
+
         * :py:exc:`OSError`: Some I/O issue with an os-release file or distro
           release file.
 
-        * :py:exc:`subprocess.CalledProcessError`: The lsb_release command had
-          some issue (other than not being available in the program execution
-          path).
-
         * :py:exc:`UnicodeError`: A data source has unexpected characters or
           uses an unexpected encoding.
         """
@@ -738,8 +753,22 @@ def __init__(
                 self.os_release_file = usr_lib_os_release_file
 
         self.distro_release_file = distro_release_file or ""  # updated later
-        self.include_lsb = include_lsb
-        self.include_uname = include_uname
+
+        is_root_dir_defined = root_dir is not None
+        if is_root_dir_defined and (include_lsb or include_uname or include_oslevel):
+            raise ValueError(
+                "Including subprocess data sources from specific root_dir is disallowed"
+                " to prevent false information"
+            )
+        self.include_lsb = (
+            include_lsb if include_lsb is not None else not is_root_dir_defined
+        )
+        self.include_uname = (
+            include_uname if include_uname is not None else not is_root_dir_defined
+        )
+        self.include_oslevel = (
+            include_oslevel if include_oslevel is not None else not is_root_dir_defined
+        )
 
     def __repr__(self) -> str:
         """Return repr of all info"""
@@ -749,10 +778,13 @@ def __repr__(self) -> str:
             "distro_release_file={self.distro_release_file!r}, "
             "include_lsb={self.include_lsb!r}, "
             "include_uname={self.include_uname!r}, "
+            "include_oslevel={self.include_oslevel!r}, "
+            "root_dir={self.root_dir!r}, "
             "_os_release_info={self._os_release_info!r}, "
             "_lsb_release_info={self._lsb_release_info!r}, "
             "_distro_release_info={self._distro_release_info!r}, "
-            "_uname_info={self._uname_info!r})".format(self=self)
+            "_uname_info={self._uname_info!r}, "
+            "_oslevel_info={self._oslevel_info!r})".format(self=self)
         )
 
     def linux_distribution(
@@ -840,6 +872,9 @@ def version(self, pretty: bool = False, best: bool = False) -> str:
             ).get("version_id", ""),
             self.uname_attr("release"),
         ]
+        if self.uname_attr("id").startswith("aix"):
+            # On AIX platforms, prefer oslevel command output.
+            versions.insert(0, self.oslevel_info())
         version = ""
         if best:
             # This algorithm uses the last version in priority order that has
@@ -980,6 +1015,12 @@ def uname_info(self) -> Dict[str, str]:
         """
         return self._uname_info
 
+    def oslevel_info(self) -> str:
+        """
+        Return AIX' oslevel command output.
+        """
+        return self._oslevel_info
+
     def os_release_attr(self, attribute: str) -> str:
         """
         Return a single named information item from the os-release file data
@@ -1139,6 +1180,16 @@ def _uname_info(self) -> Dict[str, str]:
         content = self._to_str(stdout).splitlines()
         return self._parse_uname_content(content)
 
+    @cached_property
+    def _oslevel_info(self) -> str:
+        if not self.include_oslevel:
+            return ""
+        try:
+            stdout = subprocess.check_output("oslevel", stderr=subprocess.DEVNULL)
+        except (OSError, subprocess.CalledProcessError):
+            return ""
+        return self._to_str(stdout).strip()
+
     @staticmethod
     def _parse_uname_content(lines: Sequence[str]) -> Dict[str, str]:
         if not lines:
@@ -1305,7 +1356,10 @@ def main() -> None:
 
     if args.root_dir:
         dist = LinuxDistribution(
-            include_lsb=False, include_uname=False, root_dir=args.root_dir
+            include_lsb=False,
+            include_uname=False,
+            include_oslevel=False,
+            root_dir=args.root_dir,
         )
     else:
         dist = _distro

tests/resources/distros/aix72/bin/oslevel

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo "7.2.0.0"

tests/resources/distros/aix72/bin/uname

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo "AIX 2"

tests/test_distro.py

@@ -490,9 +490,10 @@ def setup_method(self, test_method: FunctionType) -> None:
         root_dir = os.path.join(DISTROS_DIR, dist)
         self.distro = distro.LinuxDistribution(
             include_lsb=False,
+            include_uname=False,
+            include_oslevel=False,
             os_release_file="",
             distro_release_file="path-to-non-existing-file",
-            include_uname=False,
             root_dir=root_dir,
         )
 
@@ -504,7 +505,6 @@ def setup_method(self, test_method: FunctionType) -> None:
         dist = test_method.__name__.split("_")[1]
         self._setup_for_distro(os.path.join(DISTROS_DIR, dist))
         self.distro = distro.LinuxDistribution(
-            include_lsb=True,
             os_release_file="path-to-non-existing-file",
             distro_release_file="path-to-non-existing-file",
         )
@@ -610,7 +610,6 @@ def test_ubuntu14normal_lsb_release(self) -> None:
         self._setup_for_distro(os.path.join(TESTDISTROS, "lsb", "ubuntu14_normal"))
 
         self.distro = distro.LinuxDistribution(
-            include_lsb=True,
             os_release_file="path-to-non-existing-file",
             distro_release_file="path-to-non-existing-file",
         )
@@ -630,7 +629,6 @@ def test_ubuntu14nomodules_lsb_release(self) -> None:
         self._setup_for_distro(os.path.join(TESTDISTROS, "lsb", "ubuntu14_nomodules"))
 
         self.distro = distro.LinuxDistribution(
-            include_lsb=True,
             os_release_file="path-to-non-existing-file",
             distro_release_file="path-to-non-existing-file",
         )
@@ -652,7 +650,6 @@ def test_trailingblanks_lsb_release(self) -> None:
         )
 
         self.distro = distro.LinuxDistribution(
-            include_lsb=True,
             os_release_file="path-to-non-existing-file",
             distro_release_file="path-to-non-existing-file",
         )
@@ -673,7 +670,6 @@ def test_lsb_release_error_level(self, errnum: str) -> None:
         self._setup_for_distro(os.path.join(TESTDISTROS, "lsb", f"lsb_rc{errnum}"))
 
         lsb_release_info = distro.LinuxDistribution(
-            include_lsb=True,
             os_release_file="path-to-non-existing-file",
             distro_release_file="path-to-non-existing-file",
         )._lsb_release_info
@@ -1128,6 +1124,20 @@ def test_arch_release(self) -> None:
         # considered a valid distro release file:
         self._test_non_existing_release_file()
 
+    def test_aix72_release(self) -> None:
+        desired_outcome = {
+            "id": "aix",
+            "name": "AIX",
+            "pretty_name": "AIX 7.2.0.0",
+            "version": "7.2.0.0",
+            "pretty_version": "7.2.0.0",
+            "best_version": "7.2.0.0",
+            "major_version": "7",
+            "minor_version": "2",
+            "build_number": "0",
+        }
+        self._test_outcome(desired_outcome)
+
     def test_centos5_release(self) -> None:
         desired_outcome = {
             "id": "centos",