Refactor osdetect for rhel family OSes

coriolis/osmorphing/centos.py

@@ -22,7 +22,11 @@ class BaseCentOSMorphingTools(redhat.BaseRedHatMorphingTools):
     @classmethod
     def check_os_supported(cls, detected_os_info):
         supported_oses = [
-            CENTOS_STREAM_DISTRO_IDENTIFIER, CENTOS_DISTRO_IDENTIFIER]
+            CENTOS_STREAM_DISTRO_IDENTIFIER,
+            CENTOS_DISTRO_IDENTIFIER,
+            "CentOS Linux",
+            "AlmaLinux",
+        ]
         if detected_os_info['distribution_name'] not in supported_oses:
             return False
         return cls._version_supported_util(

coriolis/osmorphing/oracle.py

@@ -18,8 +18,8 @@ class BaseOracleMorphingTools(redhat.BaseRedHatMorphingTools):
 
     @classmethod
     def check_os_supported(cls, detected_os_info):
-        if detected_os_info['distribution_name'] != (
-                ORACLE_DISTRO_IDENTIFIER):
+        if detected_os_info['distribution_name'] not in (
+                ORACLE_DISTRO_IDENTIFIER, "Oracle Linux Server"):
             return False
         return cls._version_supported_util(
             detected_os_info['release_version'], minimum=6)

coriolis/osmorphing/osdetect/centos.py

@@ -1,46 +1,17 @@
 # Copyright 2020 Cloudbase Solutions Srl
 # All Rights Reserved.
 
-import re
-
-from coriolis import constants
 from coriolis.osmorphing.osdetect import base
-from oslo_log import log as logging
+from coriolis.osmorphing.osdetect import redhat_common
 
 
-LOG = logging.getLogger(__name__)
-CENTOS_DISTRO_IDENTIFIER = "CentOS"
-CENTOS_STREAM_DISTRO_IDENTIFIER = "CentOS Stream"
-ALMA_IDENTIFIER = "AlmaLinux"
+CENTOS_DISTRO_IDENTIFIER = redhat_common.CENTOS_DISTRO_IDENTIFIER
+CENTOS_STREAM_DISTRO_IDENTIFIER = redhat_common.CENTOS_STREAM_DISTRO_IDENTIFIER
 
 
 class CentOSOSDetectTools(base.BaseLinuxOSDetectTools):
 
     def detect_os(self):
-        info = {}
-        redhat_release_path = "etc/redhat-release"
-        if self._test_path(redhat_release_path):
-            release_info = self._read_file(
-                redhat_release_path).decode().splitlines()
-            if release_info:
-                m = re.match(r"^(.*) release ([0-9]+(\.[0-9]+)*)( \(.*\))?.*$",
-                             release_info[0].strip())
-                if m:
-                    distro, version, _, _ = m.groups()
-                    if (CENTOS_DISTRO_IDENTIFIER not in distro and
-                            ALMA_IDENTIFIER not in distro):
-                        LOG.debug(
-                            "Distro does not appear to be a CentOS or Alma: "
-                            f"{distro}")
-                        return {}
-
-                    distribution_name = CENTOS_DISTRO_IDENTIFIER
-                    if CENTOS_STREAM_DISTRO_IDENTIFIER in distro:
-                        distribution_name = CENTOS_STREAM_DISTRO_IDENTIFIER
-                    info = {
-                        "os_type": constants.OS_TYPE_LINUX,
-                        "distribution_name": distribution_name,
-                        "release_version": version,
-                        "friendly_release_name": "%s Version %s" % (
-                            distribution_name, version)}
-        return info
+        return redhat_common.detect_os_from_os_release(
+            self._get_os_release(),
+            match_ids={"centos", "almalinux"})

coriolis/osmorphing/osdetect/oracle.py

@@ -1,32 +1,16 @@
 # Copyright 2020 Cloudbase Solutions Srl
 # All Rights Reserved.
 
-import re
-
-from coriolis import constants
 from coriolis.osmorphing.osdetect import base
+from coriolis.osmorphing.osdetect import redhat_common
 
 
-ORACLE_DISTRO_IDENTIFIER = "Oracle Linux"
+ORACLE_DISTRO_IDENTIFIER = redhat_common.ORACLE_DISTRO_IDENTIFIER
 
 
 class OracleOSDetectTools(base.BaseLinuxOSDetectTools):
 
     def detect_os(self):
-        info = {}
-        oracle_release_path = "etc/oracle-release"
-        if self._test_path(oracle_release_path):
-            release_info = self._read_file(
-                oracle_release_path).decode().splitlines()
-            if release_info:
-                m = re.match(r"^(.*) release ([0-9].*)$",
-                             release_info[0].strip())
-                if m:
-                    distro, version = m.groups()
-                    info = {
-                        "os_type": constants.OS_TYPE_LINUX,
-                        "distribution_name": ORACLE_DISTRO_IDENTIFIER,
-                        "release_version": version,
-                        "friendly_release_name": "%s Version %s" % (
-                            distro, version)}
-        return info
+        return redhat_common.detect_os_from_os_release(
+            self._get_os_release(),
+            match_ids={"ol"})

coriolis/osmorphing/osdetect/redhat.py

@@ -1,40 +1,16 @@
 # Copyright 2020 Cloudbase Solutions Srl
 # All Rights Reserved.
 
-import re
-
-from oslo_log import log as logging
-
-from coriolis import constants
 from coriolis.osmorphing.osdetect import base
+from coriolis.osmorphing.osdetect import redhat_common
 
 
-LOG = logging.getLogger(__name__)
-RED_HAT_DISTRO_IDENTIFIER = "Red Hat Enterprise Linux"
+RED_HAT_DISTRO_IDENTIFIER = redhat_common.RED_HAT_DISTRO_IDENTIFIER
 
 
 class RedHatOSDetectTools(base.BaseLinuxOSDetectTools):
 
     def detect_os(self):
-        info = {}
-        redhat_release_path = "etc/redhat-release"
-        if self._test_path(redhat_release_path):
-            release_info = self._read_file(
-                redhat_release_path).decode().splitlines()
-            if release_info:
-                m = re.match(r"^(.*) release ([0-9].*) \((.*)\).*$",
-                             release_info[0].strip())
-                if m:
-                    distro, version, _ = m.groups()
-                    if RED_HAT_DISTRO_IDENTIFIER not in distro:
-                        LOG.debug(
-                            "Distro does not appear to be a RHEL: %s", distro)
-                        return {}
-
-                    info = {
-                        "os_type": constants.OS_TYPE_LINUX,
-                        "distribution_name": RED_HAT_DISTRO_IDENTIFIER,
-                        "release_version": version,
-                        "friendly_release_name": "%s Version %s" % (
-                            RED_HAT_DISTRO_IDENTIFIER, version)}
-        return info
+        return redhat_common.detect_os_from_os_release(
+            self._get_os_release(),
+            match_ids={"rhel"})

coriolis/osmorphing/osdetect/redhat_common.py

@@ -0,0 +1,63 @@
+# Copyright 2026 Cloudbase Solutions Srl
+# All Rights Reserved.
+
+"""Shared /etc/os-release parsing for RHEL-family osdetect tools."""
+
+from typing import Dict
+from typing import Optional
+from typing import Set
+
+from oslo_log import log as logging
+
+from coriolis import constants
+
+LOG = logging.getLogger(__name__)
+
+ROCKY_LINUX_DISTRO_IDENTIFIER = "Rocky Linux"
+CENTOS_DISTRO_IDENTIFIER = "CentOS"
+CENTOS_STREAM_DISTRO_IDENTIFIER = "CentOS Stream"
+RED_HAT_DISTRO_IDENTIFIER = "Red Hat Enterprise Linux"
+ORACLE_DISTRO_IDENTIFIER = "Oracle Linux"
+
+
+def detect_os_from_os_release(
+        os_release: Optional[Dict[str, str]],
+        *,
+        match_ids: Set[str]) -> Dict[str, str]:
+    """Detect a RHEL-family distro from /etc/os-release.
+
+    :param os_release: dict populated by ``/etc/os-release`` values, as
+        returned by ``BaseLinuxOSDetectTools._get_os_release()``.
+    :param match_ids: ``ID`` value(s) this osdetect module handles, e.g.
+        ``{"rocky"}`` or ``{"centos", "almalinux"}``.
+    """
+    if not os_release:
+        LOG.warning(
+            "Could not detect OS from /etc/os-release: os_release dict "
+            "was not provided")
+        return {}
+
+    os_id = (os_release.get("ID") or "").lower()
+    if os_id not in match_ids:
+        return {}
+
+    distribution_name = os_release.get("NAME")
+    if not distribution_name:
+        LOG.warning(
+            "Could not detect OS from /etc/os-release: matched OS ID '%s' "
+            "but NAME is missing", os_id)
+        return {}
+
+    version = os_release.get("VERSION_ID")
+    if not version:
+        LOG.warning(
+            "Could not detect OS from /etc/os-release: matched OS ID '%s' "
+            "but VERSION_ID is missing", os_id)
+        return {}
+
+    return {
+        "os_type": constants.OS_TYPE_LINUX,
+        "distribution_name": distribution_name,
+        "release_version": version,
+        "friendly_release_name": "%s Version %s" % (
+            distribution_name, version)}

coriolis/osmorphing/osdetect/rocky.py

@@ -1,40 +1,16 @@
 # Copyright 2023 Cloudbase Solutions Srl
 # All Rights Reserved.
 
-import re
-
-from coriolis import constants
 from coriolis.osmorphing.osdetect import base
-from oslo_log import log as logging
+from coriolis.osmorphing.osdetect import redhat_common
 
 
-LOG = logging.getLogger(__name__)
-ROCKY_LINUX_DISTRO_IDENTIFIER = "Rocky Linux"
+ROCKY_LINUX_DISTRO_IDENTIFIER = redhat_common.ROCKY_LINUX_DISTRO_IDENTIFIER
 
 
 class RockyLinuxOSDetectTools(base.BaseLinuxOSDetectTools):
 
     def detect_os(self):
-        info = {}
-        redhat_release_path = "etc/redhat-release"
-        if self._test_path(redhat_release_path):
-            release_info = self._read_file(
-                redhat_release_path).decode().splitlines()
-            if release_info:
-                m = re.match(r"^(.*) release ([0-9]+(\.[0-9]+)*)( \(.*\))?.*$",
-                             release_info[0].strip())
-                if m:
-                    distro, version, _, _ = m.groups()
-                    if ROCKY_LINUX_DISTRO_IDENTIFIER not in distro:
-                        LOG.debug(
-                            "Distro does not appear to be a Rocky Linux: %s",
-                            distro)
-                        return {}
-
-                    info = {
-                        "os_type": constants.OS_TYPE_LINUX,
-                        "distribution_name": ROCKY_LINUX_DISTRO_IDENTIFIER,
-                        "release_version": version,
-                        "friendly_release_name": "%s Version %s" % (
-                            ROCKY_LINUX_DISTRO_IDENTIFIER, version)}
-        return info
+        return redhat_common.detect_os_from_os_release(
+            self._get_os_release(),
+            match_ids={"rocky"})