sysinfo: move os-release parsing into separate module

Any opened files are now also closed after reading them.

rust2rpm/__main__.py

@@ -19,6 +19,7 @@ from . import cfg, licensing, generator, log, util
 from .core.metadata import Metadata
 from .cratesio import download_crate, NoVersionsError
 from .distgit import get_package_info
+from .sysinfo import get_default_target
 
 
 LICENSES = re.compile(
@@ -58,40 +59,6 @@ def sortify(func):
     return functools.update_wrapper(wrapper, func)
 
 
-def read_os_release():
-    try:
-        f = open("/etc/os-release")
-    except FileNotFoundError:
-        f = open("/usr/lib/os-release")
-
-    for line in f:
-        line = line.rstrip()
-        if not line or line.startswith("#"):
-            continue
-        if m := re.match(r"([A-Z][A-Z_0-9]+)=(.*)", line):
-            name, val = m.groups()
-            if val and val[0] in "\"'":
-                val = ast.literal_eval(val)
-            yield name, val
-
-
-def get_default_target():
-    os_release = dict(read_os_release())
-    os_id = os_release.get("ID")
-    # ID_LIKE is a space-separated list of identifiers like ID
-    os_like = os_release.get("ID_LIKE", "").split()
-
-    # Order matters here!
-    if "mageia" in (os_id, *os_like):
-        return "mageia"
-    elif "fedora" in (os_id, *os_like):
-        return "fedora"
-    elif "suse" in os_like:
-        return "opensuse"
-    else:
-        return "plain"
-
-
 def file_mtime(path):
     return datetime.fromtimestamp(os.stat(path).st_mtime, timezone.utc).isoformat()
 

rust2rpm/sysinfo.py

@@ -0,0 +1,43 @@
+import ast
+import re
+
+
+def read_os_release() -> dict[str, str]:
+    try:
+        with open("/etc/os-release") as file:
+            contents = file.read()
+    except FileNotFoundError:
+        with open("/usr/lib/os-release") as file:
+            contents = file.read()
+
+    data = dict()
+
+    for line in contents.splitlines():
+        line = line.rstrip()
+        if not line or line.startswith("#"):
+            continue
+        if m := re.match(r"([A-Z][A-Z_0-9]+)=(.*)", line):
+            name, val = m.groups()
+            if val and val[0] in "\"'":
+                val = ast.literal_eval(val)
+            data[name] = val
+
+    return data
+
+
+def get_default_target() -> str:
+    os_release = read_os_release()
+    os_id = os_release.get("ID")
+
+    # ID_LIKE is a space-separated list of identifiers like ID
+    os_like = os_release.get("ID_LIKE", "").split()
+
+    # Order matters here!
+    if "mageia" in (os_id, *os_like):
+        return "mageia"
+    elif "fedora" in (os_id, *os_like):
+        return "fedora"
+    elif "suse" in os_like:
+        return "opensuse"
+    else:
+        return "plain"