yum: take care of stale/invalid yum.pid (#58457)

* yum: take care of stale/invalid yum.pid

* Add changelog

changelogs/fragments/yum-handle-stale-lock-file.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - yum - handle stale/invalid yum.pid lock file (https://github.com/ansible/ansible/issues/57189)

lib/ansible/module_utils/yumdnf.py

@@ -126,15 +126,25 @@ class YumDnf(with_metaclass(ABCMeta, object)):
         # default isn't a bad idea
         self.lockfile = '/var/run/yum.pid'
 
+    def is_lockfile_pid_valid(self):
+        raise NotImplementedError
+
+    def _is_lockfile_present(self):
+        return (os.path.isfile(self.lockfile) or glob.glob(self.lockfile)) and self.is_lockfile_pid_valid()
+
     def wait_for_lock(self):
         '''Poll until the lock is removed if timeout is a positive number'''
-        if (os.path.isfile(self.lockfile) or glob.glob(self.lockfile)):
-            if self.lock_timeout > 0:
-                for iteration in range(0, self.lock_timeout):
-                    time.sleep(1)
-                    if not os.path.isfile(self.lockfile) and not glob.glob(self.lockfile):
-                        return
-            self.module.fail_json(msg='{0} lockfile is held by another process'.format(self.pkg_mgr_name))
+
+        if not self._is_lockfile_present():
+            return
+
+        if self.lock_timeout > 0:
+            for iteration in range(0, self.lock_timeout):
+                time.sleep(1)
+                if not self._is_lockfile_present():
+                    return
+
+        self.module.fail_json(msg='{0} lockfile is held by another process'.format(self.pkg_mgr_name))
 
     def listify_comma_sep_strings_in_list(self, some_list):
         """

lib/ansible/modules/packaging/os/dnf.py

@@ -329,6 +329,11 @@ class DnfModule(YumDnf):
         except AttributeError:
             self.with_modules = False
 
+    def is_lockfile_pid_valid(self):
+        # FIXME? it looks like DNF takes care of invalid lock files itself?
+        # https://github.com/ansible/ansible/issues/57189
+        return True
+
     def _sanitize_dnf_error_msg(self, spec, error):
         """
         For unhandled dnf.exceptions.Error scenarios, there are certain error

lib/ansible/modules/packaging/os/yum.py

@@ -336,6 +336,7 @@ from ansible.module_utils._text import to_native, to_text
 from ansible.module_utils.urls import fetch_url
 from ansible.module_utils.yumdnf import YumDnf, yumdnf_argument_spec
 
+import errno
 import os
 import re
 import tempfile
@@ -410,6 +411,44 @@ class YumModule(YumDnf):
                     else:
                         raise e
 
+    def is_lockfile_pid_valid(self):
+        try:
+            with open(self.lockfile, 'r') as f:
+                oldpid = int(f.readline())
+        except ValueError:
+            # invalid data
+            os.unlink(self.lockfile)
+            return False
+        except (IOError, OSError) as e:
+            self.module.fail_json(msg="Failure opening %s: %s" % (self.lockfile, to_native(e)))
+
+        if oldpid == os.getpid():
+            # that's us?
+            os.unlink(self.lockfile)
+            return False
+
+        try:
+            with open("/proc/%d/stat" % oldpid, 'r') as f:
+                stat = f.readline()
+
+            if stat.split()[2] == 'Z':
+                # Zombie
+                os.unlink(self.lockfile)
+                return False
+        except IOError:
+            try:
+                os.kill(oldpid, 0)
+            except OSError as e:
+                if e.errno == errno.ESRCH:
+                    # No such process
+                    os.unlink(self.lockfile)
+                    return False
+
+                self.module.fail_json(msg="Unable to check PID %s in  %s: %s" % (oldpid, self.lockfile, to_native(e)))
+
+        # another copy seems to be running
+        return True
+
     def yum_base(self):
         my = yum.YumBase()
         my.preconf.debuglevel = 0

test/integration/targets/yum/tasks/lock.yml

@@ -0,0 +1,28 @@
+- block:
+  - name: Make sure testing package is not installed
+    yum:
+      name: sos
+      state: absent
+
+  - name: Create bogus lock file
+    copy:
+      content: bogus content for this lock file
+      dest: /var/run/yum.pid
+
+  - name: Install a package, lock file should be deleted by the module
+    yum:
+      name: sos
+      state: present
+    register: yum_result
+
+  - assert:
+      that:
+        - yum_result is success
+
+  always:
+    - name: Clean up
+      yum:
+        name: sos
+        state: absent
+
+  when: ansible_pkg_mgr == 'yum'

test/integration/targets/yum/tasks/main.yml

@@ -60,3 +60,8 @@
 - import_tasks: check_mode_consistency.yml
   when:
     - (ansible_distribution in ['RedHat', 'CentOS', 'ScientificLinux'] and ansible_distribution_major_version|int == 7)
+
+
+- import_tasks: lock.yml
+  when:
+    - ansible_distribution in ['RedHat', 'CentOS', 'ScientificLinux']