jw.pkg.App: Add more distro_xxx properties

In addition to the existing propert distro_id, add the properties
distro_codename, distro_name, distro_cascade and distro_gnu_triplet.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/App.py

@@ -3,6 +3,8 @@
 # This source code file is a merge of various build tools and a horrible mess.
 #
 
+from __future__ import annotations
+
 from typing import TypeAlias
 
 import os, sys, argparse, pwd, re
@@ -210,7 +212,10 @@ class App(Base):
         # -- Members without default values
         self.__opt_os: str|None = None
         self.__top_name: str|None = None
+        self.__os_release: str|None = None
         self.__distro_id: str|None = None
+        self.__distro_name: str|None = None
+        self.__distro_codename: str|None = None
         self.__os_cascade: list[str]|None = None
         self.__res_cache = ResultCache()
         self.__topdir: str|None = None
@@ -253,16 +258,95 @@ class App(Base):
         return self.__projs_root
 
     @property
-    def distro_id(self):
+    def os_release(self) -> str:
-        if self.__distro_id is None:
+        if self.__os_release is None:
             os_release = '/etc/os-release'
             with open(os_release, 'r') as file:
-                m = re.search(r'^\s*ID\s*=\s*("?)([^"\n]+)\1\s*$', file.read(), re.MULTILINE)
+                self.__os_release = file.read()
+        return self.__os_release
+
+    def os_release_field(self, key: str, throw: bool=False) -> str:
+        m = re.search(r'^\s*' + key + r'\s*=\s*("?)([^"\n]+)\1\s*$', self.os_release, re.MULTILINE)
         if m is None:
-                    raise Exception(f'Could not read "ID=" from "{os_release}"')
+            if throw:
-                self.__distro_id = m.group(2)
+                raise Exception(f'Could not read "{key}=" from /etc/os-release')
+            return None
+        return m.group(2)
+
+    @property
+    def distro_name(self) -> str:
+        if self.__distro_name is None:
+            self.__distro_name = self.os_release_field('NAME', throw=True)
+        return self.__distro_name
+
+    @property
+    def distro_id(self) -> str:
+        if self.__distro_id is None:
+            val = self.os_release_field('ID', throw=True)
+            match val:
+                case 'opensuse-tumbleweed':
+                    self.__distro_id = 'opensuse'
+                case 'kali':
+                    self.__distro_id = 'kali'
+                case _:
+                    self.__distro_id = val
         return self.__distro_id
 
+    @property
+    def distro_codename(self) -> str:
+        match self.distro_id:
+            case 'opensuse':
+                self.__distro_codename = \
+                    self.os_release_field('ID', throw=True).split('-')[1]
+            case 'kali':
+                self.__distro_codename = \
+                    self.os_release_field('VERSION_CODENAME', throw=True).split('-')[1]
+            case _:
+                self.__distro_codename = \
+                        self.os_release_field('VERSION_CODENAME', throw=True)
+        return self.__distro_codename
+
+    @property
+    def distro_cascade(self) -> str:
+        return ' '.join(self.os_cascade())
+
+    @property
+    def distro_gnu_triplet(self) -> str:
+
+        import sysconfig
+        import shutil
+        import subprocess
+
+        # Best: GNU host triplet Python was built for
+        for key in ("HOST_GNU_TYPE", "BUILD_GNU_TYPE"):  # BUILD_GNU_TYPE can exist too
+            ret = sysconfig.get_config_var(key)
+            if isinstance(ret, str) and ret:
+                return ret
+
+        # Common on Debian/Ubuntu: multiarch component (often looks like a triplet)
+        ret = sysconfig.get_config_var("MULTIARCH")
+        if isinstance(ret, str) and ret:
+            return ret
+
+        # Sometimes exposed (privately) by CPython
+        ret = getattr(sys.implementation, "_multiarch", None)
+        if isinstance(ret, str) and ret:
+            return ret
+
+        # Last resort: ask the system compiler
+        for cc in ("gcc", "cc", "clang"):
+            path = shutil.which(cc)
+            if not path:
+                continue
+            try:
+                ret = subprocess.check_output([path, "-dumpmachine"], text=True, stderr=subprocess.DEVNULL).strip()
+                if ret:
+                    return ret
+            except Exception:
+                pass
+
+        raise RuntimeError('Failed to get GNU triplet from running machine')
+
     def find_dir(self, name: str, search_subdirs: list[str]=[], search_absdirs: list[str]=[], pretty: bool=True):
         return self.__find_dir(name, search_subdirs, search_absdirs, pretty)