[Kimchi-devel] [PATCH v2 1/4] Add functions for package manager monitoring

[Aline Manera]

On 04/10/2015 17:44, Jose Ricardo Ziviani wrote:
>   - Kimchi package manager classes are now able to know if there is already a
>     package manager instance running in the system and where to find the
>     default logfiles for those package managers.
>
> Signed-off-by: Jose Ricardo Ziviani <joserz at linux.vnet.ibm.com>
> ---
>   src/wok/plugins/kimchi/i18n.py     |  1 +
>   src/wok/plugins/kimchi/swupdate.py | 84 ++++++++++++++++++++++++++++++++++++++
>   2 files changed, 85 insertions(+)
>
> diff --git a/src/wok/plugins/kimchi/i18n.py b/src/wok/plugins/kimchi/i18n.py
> index ea325b8..416d951 100644
> --- a/src/wok/plugins/kimchi/i18n.py
> +++ b/src/wok/plugins/kimchi/i18n.py
> @@ -270,6 +270,7 @@ messages = {
>       "KCHPKGUPD0002E": _("Package %(name)s is not marked to be updated."),
>       "KCHPKGUPD0003E": _("Error while getting packages marked to be updated. Details: %(err)s"),
>       "KCHPKGUPD0004E": _("There is no compatible package manager for this system."),
> +    "KCHPKGUPD0005E": _("There is a package manager instance running in the system."),
>
>       "KCHUTILS0003E": _("Unable to choose a virtual machine name"),
>
> diff --git a/src/wok/plugins/kimchi/swupdate.py b/src/wok/plugins/kimchi/swupdate.py
> index b966424..f86c12e 100644
> --- a/src/wok/plugins/kimchi/swupdate.py
> +++ b/src/wok/plugins/kimchi/swupdate.py
> @@ -17,6 +17,7 @@
>   # License along with this library; if not, write to the Free Software
>   # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
>
> +import fcntl
>   import os
>   import signal
>   import subprocess
> @@ -27,6 +28,7 @@ from wok.exception import NotFoundError, OperationFailed
>   from wok.utils import run_command, wok_log
>
>   from config import kimchiLock
> +from psutil import pid_exists
>   from yumparser import get_yum_packages_list_update
>
>
> @@ -157,6 +159,24 @@ class YumUpdate(object):
>       def __init__(self):
>           self._pkgs = {}
>           self.update_cmd = ["yum", "-y", "update"]
> +        self.logfile = self._get_output_log()
> +
> +    def _get_output_log(self):
> +        """
> +        Return the logfile path
> +        """
> +        try:
> +            with open('/etc/yum.conf', 'r') as config:
> +                for line in config:
> +                    if 'logfile' in line:
> +                        logfile = line.split('=')[1].strip()
> +                        if not logfile:
> +                            return None
> +
> +                        return logfile
> +

You can use ConfigObj to parse the file. That way we avoid the above loop.

> +        except (IndexError, IOError):
> +            return None
>
>       def _refreshUpdateList(self):
>           """
> @@ -177,6 +197,9 @@ class YumUpdate(object):
>           package = {'package_name': <string>, 'version': <string>,
>                      'arch': <string>, 'repository': <string>}
>           """
> +        if self.isRunning():
> +            raise OperationFailed('KCHPKGUPD0005E')
> +
>           self._refreshUpdateList()
>           pkg_list = []
>           for pkg in self._pkgs:
> @@ -185,6 +208,25 @@ class YumUpdate(object):
>               pkg_list.append(package)
>           return pkg_list
>
> +    def isRunning(self):
> +        """
> +        Return True whether the YUM package manager is already running or
> +        False otherwise.
> +        """
> +        try:
> +            with open('/var/run/yum.pid', 'r') as pidfile:
> +                pid = int(pidfile.read().rstrip('\n'))
> +
> +        # cannot find pidfile, assumes yum is not running
> +        except (IOError, ValueError):
> +            return False
> +
> +        # the pidfile exists and it lives in process table
> +        if pid_exists(pid):
> +            return True
> +
> +        return False
> +
>
>   class AptUpdate(object):
>       """
> @@ -196,6 +238,7 @@ class AptUpdate(object):
>           self._pkgs = {}
>           self.pkg_lock = getattr(__import__('apt_pkg'), 'SystemLock')
>           self.update_cmd = ['apt-get', 'upgrade', '-y']
> +        self.logfile = '/var/log/apt/term.log'
>
>       def _refreshUpdateList(self):
>           """
> @@ -218,6 +261,9 @@ class AptUpdate(object):
>           package = {'package_name': <string>, 'version': <string>,
>                      'arch': <string>, 'repository': <string>}
>           """
> +        if self.isRunning():
> +            raise OperationFailed('KCHPKGUPD0005E')
> +
>           kimchiLock.acquire()
>           self._refreshUpdateList()
>           kimchiLock.release()
> @@ -231,6 +277,21 @@ class AptUpdate(object):
>
>           return pkg_list
>
> +    def isRunning(self):
> +        """
> +        Return True whether the APT package manager is already running or
> +        False otherwise.
> +        """
> +        try:
> +            with open('/var/lib/dpkg/lock', 'w') as lockfile:
> +                fcntl.lockf(lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
> +
> +        # cannot open dpkg lock file to write in exclusive mode means the
> +        # apt is currently running
> +        except IOError:
> +            return True
> +
> +        return False
>
>   class ZypperUpdate(object):
>       """
> @@ -242,6 +303,7 @@ class ZypperUpdate(object):
>           self._pkgs = {}
>           self.update_cmd = ["zypper", "--non-interactive", "update",
>                              "--auto-agree-with-licenses"]
> +        self.logfile = '/var/log/zypp/history'
>
>       def _refreshUpdateList(self):
>           """
> @@ -268,7 +330,29 @@ class ZypperUpdate(object):
>           package = {'package_name': <string>, 'version': <string>,
>                      'arch': <string>, 'repository': <string>}
>           """
> +        if self.isRunning():
> +            raise OperationFailed('KCHPKGUPD0005E')
> +
>           kimchiLock.acquire()
>           self._refreshUpdateList()
>           kimchiLock.release()
>           return self._pkgs
> +
> +    def isRunning(self):
> +        """
> +        Return True whether the Zypper package manager is already running or
> +        False otherwise.
> +        """
> +        try:
> +            with open('/var/run/zypp.pid', 'r') as pidfile:
> +                pid = int(pidfile.read().rstrip('\n'))
> +
> +        # cannot find pidfile, assumes yum is not running
> +        except (IOError, ValueError):
> +            return False
> +
> +        # the pidfile exists and it lives in process table
> +        if pid_exists(pid):
> +            return True
> +
> +        return False