add the --scrub option for cleaning up cache (BZ# 450726)

Added the command line option:
    --scrub=[all,chroot,cache,root-cache,c-cache,yum-cache]
which allows selective cleanup of the various cache's maintained
by mock (on on mock's behalf).

Also added logic to umountall() to umount in reverse order of mount.

Signed-off-by: Clark Williams <williams@redhat.com>

2 files changed, 56 insertions, 17 deletions

diff --git a/py/mock.py b/py/mock.py
index 8f58031..6702ba6 100755
--- a/py/mock.py
+++ b/py/mock.py
@@ -20,7 +20,7 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 """
     usage:
-           mock [options] {--init|--clean}
+           mock [options] {--init|--clean|--scrub=[all,chroot,cache,root-cache,c-cache,yum-cache]}
            mock [options] [--rebuild] /path/to/srpm(s)
            mock [options] {--shell|--chroot} <cmd>
            mock [options] --installdeps {SRPM|RPM}
@@ -64,6 +64,10 @@ import mock.backend
 import mock.uid
 import mock.util
 
+def scrub_callback(option, opt, value, parser):
+    parser.values.scrub.append(value)
+    parser.values.mode = "clean"
+
 def command_parse(config_opts):
     """return options and args from parsing the command line"""
     parser = OptionParser(usage=__doc__, version=__VERSION__)
@@ -85,6 +89,12 @@ def command_parse(config_opts):
     parser.add_option("--clean", action="store_const", const="clean",
                       dest="mode",
                       help="completely remove the specified chroot")
+    scrub_choices = ('chroot', 'cache', 'root-cache', 'c-cache', 'yum-cache', 'all')
+    scrub_metavar = "[all|chroot|cache|root-cache|c-cache|yum-cache]"
+    parser.add_option("--scrub", action="callback", type="choice", default=[],
+                      choices=scrub_choices, metavar=scrub_metavar,
+                      callback=scrub_callback,
+                      help="completely remove the specified chroot or cache dir or all of the chroot and cache")
     parser.add_option("--init", action="store_const", const="init", dest="mode",
                       help="initialize the chroot, do not build anything")
     parser.add_option("--installdeps", action="store_const", const="installdeps",
@@ -576,7 +586,10 @@ def main(ret):
         chroot.init()
 
     elif options.mode == 'clean':
-        chroot.clean()
+        if len(options.scrub) == 0:
+            chroot.clean()
+        else:
+            chroot.scrub(options.scrub)
 
     elif options.mode == 'shell':
         chroot.tryLockBuildRoot()
diff --git a/py/mock/backend.py b/py/mock/backend.py
index ca06f59..f8cb412 100644
--- a/py/mock/backend.py
+++ b/py/mock/backend.py
@@ -135,6 +135,29 @@ class Root(object):
         self.chrootWasCleaned = True
 
     decorate(traceLog())
+    def scrub(self, scrub_opts):
+        """clean out chroot and/or cache dirs with extreme prejudice :)"""
+        self.tryLockBuildRoot()
+        self.state("clean")
+        self._callHooks('clean')
+        for scrub in scrub_opts:
+            if scrub == 'all':
+                mock.util.rmtree(self.basedir)
+                self.chrootWasCleaned = True
+                mock.util.rmtree(self.cachedir)
+            elif scrub == 'chroot':
+                mock.util.rmtree(self.basedir)
+                self.chrootWasCleaned = True
+            elif scrub == 'cache':
+                mock.util.rmtree(self.cachedir)
+            elif scrub == 'c-cache':
+                mock.util.rmtree(os.path.join(self.cachedir, 'ccache'))
+            elif scrub == 'root-cache':
+                mock.util.rmtree(os.path.join(self.cachedir, 'root_cache'))
+            elif scrub == 'yum-cache':
+                mock.util.rmtree(os.path.join(self.cachedir, 'yum_cache'))
+
+    decorate(traceLog())
     def tryLockBuildRoot(self):
         self.state("lock buildroot")
         try:
@@ -282,24 +305,24 @@ class Root(object):
             self._mountall()
             if self.chrootWasCleaned:
                 self._yum(self.chroot_setup_cmd, returnOutput=1)
-        finally:
-            self._umountall()
 
-        # create user
-        self._makeBuildUser()
+            # create user
+            self._makeBuildUser()
 
-        # create rpmbuild dir
-        self._buildDirSetup()
+            # create rpmbuild dir
+            self._buildDirSetup()
 
-        # set up timezone to match host
-        localtimedir = self.makeChrootPath('etc')
-        localtimepath = self.makeChrootPath('etc', 'localtime')
-        if os.path.exists(localtimepath):
-            os.remove(localtimepath)
-        shutil.copy2('/etc/localtime', localtimedir)
+            # set up timezone to match host
+            localtimedir = self.makeChrootPath('etc')
+            localtimepath = self.makeChrootPath('etc', 'localtime')
+            if os.path.exists(localtimepath):
+                os.remove(localtimepath)
+            shutil.copy2('/etc/localtime', localtimedir)
 
-        # done with init
-        self._callHooks('postinit')
+            # done with init
+            self._callHooks('postinit')
+        finally:
+            self._umountall()
 
     decorate(traceLog())
     def _setupDev(self):
@@ -589,7 +612,10 @@ class Root(object):
     decorate(traceLog())
     def _umountall(self):
         """umount all mounted chroot fs."""
-        for cmd in self.umountCmds:
+        # Unwind mounts by umounting in the opposite order of the mounts
+        umountCmds = self.umountCmds
+        umountCmds.reverse()
+        for cmd in umountCmds:
             self.root_log.debug(cmd)
             mock.util.do(cmd, raiseExc=0, shell=True)