From 02f41081d7789688ec8e22b8a9606b72fadb3e2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20B=C3=BCchse?= <matthias.buechse@cloudandheat.com>
Date: Fri, 16 Aug 2024 14:07:59 +0200
Subject: [PATCH] =?UTF-8?q?bugfix:=20use=20os=5Fdistro=20and=20os=5Fversio?=
 =?UTF-8?q?n=20to=20determine=20distro=20and=20version=20=E2=80=A6=20(#698?=
 =?UTF-8?q?)?=
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thanks to @gtema for the suggestion and review and @martinmo for additional review

Signed-off-by: Matthias Büchse <matthias.buechse@cloudandheat.com>
---
 Tests/iaas/entropy/entropy-check.py | 72 +++++++++++++++++------------
 1 file changed, 43 insertions(+), 29 deletions(-)

diff --git a/Tests/iaas/entropy/entropy-check.py b/Tests/iaas/entropy/entropy-check.py
index 91f53fd93..da9f6dfa0 100755
--- a/Tests/iaas/entropy/entropy-check.py
+++ b/Tests/iaas/entropy/entropy-check.py
@@ -402,38 +402,52 @@ def handle(self, record):
         self.bylevel[record.levelno] += 1
 
 
-def _deduce_version(name, ubuntu_ver=re.compile(r"\d\d\.\d\d\Z"), debian_ver=re.compile(r"\d+\Z")):
-    """helper for `select_deb_image` to deduce a version even if its only given via codename"""
-    canonicalized = [part.strip() for part in name.lower().split()]
-    if "debian" in canonicalized:
-        # don't even consider "stretch" (9) here
-        codenames = ("buster", "bullseye", "bookworm")
-        for idx, name in enumerate(codenames):
-            if name in canonicalized:
-                return idx + 10
-        for part in canonicalized:
-            if debian_ver.match(part):
-                return int(part)
-    elif "ubuntu" in canonicalized:
-        for part in canonicalized:
-            if ubuntu_ver.match(part):
-                return int(part[:2] + part[3:])
-    return -1
+# the following functions are used to map any OpenStack Image to a pair of integers
+# used for sorting the images according to fitness for our test
+# - debian take precedence over ubuntu
+# - higher versions take precedence over lower ones
+
+# only list stable versions here
+DEBIAN_CODENAMES = {
+    "buster": 10,
+    "bullseye": 11,
+    "bookworm": 12,
+}
+
+
+def _deduce_sort_debian(os_version, debian_ver=re.compile(r"\d+\Z")):
+    if debian_ver.match(os_version):
+        return 2, int(os_version)
+    return 2, DEBIAN_CODENAMES.get(os_version, 0)
+
+
+def _deduce_sort_ubuntu(os_version, ubuntu_ver=re.compile(r"\d\d\.\d\d\Z")):
+    if ubuntu_ver.match(os_version):
+        return 1, int(os_version.replace(".", ""))
+    return 1, 0
+
+
+# map lower-case distro name to version deducing function
+DISTROS = {
+    "ubuntu": _deduce_sort_ubuntu,
+    "debian": _deduce_sort_debian,
+}
+
+
+def _deduce_sort(img):
+    # avoid private images here
+    # (note that with SCS, public images MUST have os_distro and os_version, but we check nonetheless)
+    if img.visibility != 'public' or not img.os_distro or not img.os_version:
+        return 0, 0
+    deducer = DISTROS.get(img.os_distro.strip().lower())
+    if deducer is None:
+        return 0, 0
+    return deducer(img.os_version.strip().lower())
 
 
 def select_deb_image(images):
-    """From a list of OpenStack image objects, select a recent Debian derivative.
-
-    Try Debian first, then Ubuntu.
-    """
-    for prefix in ("Debian ", "Ubuntu "):
-        imgs = sorted(
-            [img for img in images if img.name.startswith(prefix)],
-            key=lambda img: _deduce_version(img.name),
-        )
-        if imgs:
-            return imgs[-1]
-    return None
+    """From a list of OpenStack image objects, select a recent Debian derivative."""
+    return max(images, key=_deduce_sort, default=None)
 
 
 def print_result(check_id, passed):