Ticket #540: APT.py

'''This is the bcfg2 support for apt-get'''
__revision__ = '$Revision: 4923 $'

import apt.cache
import os, re
import Bcfg2.Client.Tools

class APT(Bcfg2.Client.Tools.Tool):
    '''The Debian toolset implements package and service operations and inherits
    the rest from Toolset.Toolset'''
    __name__ = 'APTng'
    __execs__ = ['/usr/bin/debsums', '/usr/bin/apt-get', '/usr/bin/dpkg']
    __important__ = ["/etc/apt/sources.list",
                     "/var/cache/debconf/config.dat", 
                     "/var/cache/debconf/templates.dat",
                     '/etc/passwd', '/etc/group', 
                     '/etc/apt/apt.conf', '/etc/dpkg/dpkg.cfg']
    __handles__ = [('Package', 'deb')]
    __req__ = {'Package': ['name', 'version']}
    pkgcmd = 'apt-get ' + \
             '-o DPkg::Options::=--force-overwrite ' + \
             '-o DPkg::Options::=--force-confold ' + \
             '--reinstall ' + \
             '-q=2 ' + \
             '--force-yes ' + \
             '-y install %s'
    
    def __init__(self, logger, cfg, setup):
        Bcfg2.Client.Tools.Tool.__init__(self, logger, cfg, setup)
        self.cfg = cfg
        os.environ["DEBIAN_FRONTEND"] = 'noninteractive'
        self.pkg_cache = apt.cache.Cache()
        self.actions = {}
        if self.setup['kevlar'] and not self.setup['dryrun']:
            self.cmd.run("dpkg --force-confold --configure --pending")
            self.cmd.run("apt-get clean")
            try:
                self.pkg_cache.update()
            except:
                self.logger.error("Failed to update apt cache")

    def FindExtra(self):
        '''Find extra packages'''
        packages = [entry.get('name') for entry in self.getSupportedEntries()]
        extras = [(p.name, p.installedVersion) for p in self.pkg_cache
                  if p.isInstalled and p.name not in packages]
        return [Bcfg2.Client.XML.Element('Package', name=name, \
                                         type='deb', version=version) \
                                         for (name, version) in extras]

    def VerifyDebsums(self, entry, modlist):
        output = self.cmd.run("/usr/bin/debsums -as %s" % entry.get('name'))[1]
        if len(output) == 1 and "no md5sums for" in output[0]:
            self.logger.info("Package %s has no md5sums. Cannot verify" % \
                             entry.get('name'))
            entry.set('qtext', "Reinstall Package %s-%s to setup md5sums? (y/N) " \
                      % (entry.get('name'), entry.get('version')))
            return False
        files = []
        for item in output:
            if "checksum mismatch" in item:
                files.append(item.split()[-1])
            elif "can't open" in item:
                files.append(item.split()[5])
            elif "is not installed" in item:
                self.logger.error("Package %s is not fully installed" \
                                  % entry.get('name'))
            else:
                self.logger.error("Got Unsupported pattern %s from debsums" \
                                  % item)
                files.append(item)
        # We check if there is file in the checksum to do
        if files:
            # if files are found there we try to be sure our modlist is sane
            # with erroneous symlinks
            modlist = [os.path.realpath(filename) for filename in modlist]
            bad = [filename for filename in files if filename not in modlist]
            if bad:
                self.logger.info("Package %s failed validation. Bad files are:" % \
                                 entry.get('name'))
                self.logger.info(bad)
                entry.set('qtext',
                          "Reinstall Package %s-%s to fix failing files? (y/N) " % \
                          (entry.get('name'), entry.get('version')))
                return False
        return True

    def VerifyPackage(self, entry, modlist, checksums=True):
        '''Verify package for entry'''
        if not entry.attrib.has_key('version'):
            self.logger.info("Cannot verify unversioned package %s" %
                             (entry.attrib['name']))
            return False
        pkgname = entry.get('name')
        if not self.pkg_cache.has_key(pkgname) \
               or not self.pkg_cache[pkgname].isInstalled:
            self.logger.info("Package %s not installed" % (entry.get('name')))
            entry.set('current_exists', 'false')
            return False
            
        pkg = self.pkg_cache[pkgname]
        if entry.get('version') == 'auto':
            if self.pkg_cache._depcache.IsUpgradable(pkg._pkg):
                desiredVersion = pkg.candidateVersion
            else:
                desiredVersion = pkg.installedVersion
        else:
            desiredVersion = entry.get('version')
        if desiredVersion != pkg.installedVersion:
            entry.set('current_version', pkg.installedVersion)
            entry.set('qtext', "Modify Package %s (%s -> %s)? (y/N) " % \
                      (entry.get('name'), entry.get('current_version'),
                       entry.get('version')))
            return False
        else:
            # version matches
            if not self.setup['quick'] and entry.get('verify', 'true') == 'true' \
                   and checksums:
                pkgsums = self.VerifyDebsums(entry, modlist)
                return pkgsums

    def Remove(self, packages):
        '''Deal with extra configuration detected'''
        pkgnames = " ".join([pkg.get('name') for pkg in packages])
        if len(packages) > 0:
            self.logger.info('Removing packages:')
            self.logger.info(pkgnames)
            for pkg in pkgnames:
                self.pkg_cache[pkg].markDelete(purge=True)
            self.pkg_cache.commit()
            self.modified += packages
            self.extra = self.FindExtra()
              
    def Install(self, packages, states):
        # it looks like you can't install arbitrary versions of software
        # out of the pkg cache, we will still need to call apt-get
        ipkgs = []
        for pkg in packages:
            if not self.pkg_cache.has_key(pkg.get('name')):
                self.logger.error("APT has no information about package %s" % (pkg.get('name')))
                continue
            if pkg.get('version') == 'auto':
                ipkgs.append("%s=%s" % (pkg.get('name'),
                                        self.pkg_cache[pkg.get('name')].candidateVersion))
                continue
            if pkg.get('version') in \
               [p.VerStr for p in self.pkg_cache[pkg.get('name')]._pkg.VersionList]:
                ipkgs.append("%s=%s" % (pkg.get('name'), pkg.get('version')))
        rc = self.cmd.run(self.pkgcmd % (" ".join(ipkgs)))[0]
        if rc:
            self.logger.error("APT command failed")
        self.pkg_cache = apt.cache.Cache()
        self.extra = self.FindExtra()
        for package in packages:
            states[package] = self.VerifyPackage(package, [], checksums=False)
            if states[package]:
                self.modified.append(package)