getting edit-livecd working

[Tim Coote]

Hullo
I'm trying to modify an f16 livecd to enable ssh on boot, so that I can get to it when
it's not in front of me.

I'm using a physical laptop with an f16 install from livecd and then yum update'd

the stock f16 livecd-tools falls over with this error:
  File "/usr/lib/python2.7/site-packages/imgcreate/creator.py", line 464, in
__destroy_selinuxfs
    arglist = ["/bin/umount", self._instroot + self.__selinux_mountpoint +
"/load"]
AttributeError: 'LiveImageEditor' object has no attribute
'_ImageCreator__selinux_mountpoint'

Which if I look in the source of /usr/bin/edit-livecd seems to be understandable.

If I update to the updates-testing repo version of livecd-tools:
livecd-tools-16.11-1.fc16.i686

I get this error:

[tim@pluto make]$ sudo edit-livecd -n withssh Fedora-16-i686-Live-Desktop.iso 
Fedora-16-i686-Live-Desktop.iso
umount: /var/tmp/edit-liveos-W2ZKFk/install_root/sys/fs/selinux/load: not found
Traceback (most recent call last):
  File "/usr/bin/edit-livecd", line 723, in <module>
    sys.exit(main())
  File "/usr/bin/edit-livecd", line 697, in main
    editor.mount(LiveOS, cachedir = None)
  File "/usr/bin/edit-livecd", line 251, in mount
    os.symlink("../proc/mounts", self._instroot + "/etc/mtab")
OSError: [Errno 17] File exists

I *think* that this is because self._instroot is set to None in class
LiveImageEditor(LiveImageCreator):, and does not appear to be reassigned.

Should the f16 livecd-tools version of edit-livecd work and are there any particular
options/configurations that I must set to get it to work? Or should I just install from
somewhere else (I'd much rather not do that as it will screw up the other dependencies
on the box, but if necessary, I could spin up a VM and do it on that.)

All help gratefully received.

Tim

[Frederick Grose]

On Sat, Mar 31, 2012 at 10:13 AM, Tim Coote <tim+fedoraproject.org(a)coote.org
>  wrote: 
>  Hullo
>  I'm trying to modify an f16 livecd to enable ssh on boot, so that I can
>  get to it when it's not in front of me.
>
>  I'm using a physical laptop with an f16 install from livecd and then yum
>  update'd
>
>  the stock f16 livecd-tools falls over with this error:
>   File "/usr/lib/python2.7/site-packages/imgcreate/creator.py", line 464,
>  in __destroy_selinuxfs
>     arglist = ["/bin/umount", self._instroot + self.__selinux_mountpoint +
>  "/load"]
>  AttributeError: 'LiveImageEditor' object has no attribute
>  '_ImageCreator__selinux_mountpoint'
>
>  Which if I look in the source of /usr/bin/edit-livecd seems to be
>  understandable.
>
>  If I update to the updates-testing repo version of livecd-tools:
>  livecd-tools-16.11-1.fc16.i686
>
>  I get this error:
>
>  [tim@pluto make]$ sudo edit-livecd -n withssh
>  Fedora-16-i686-Live-Desktop.iso
>  Fedora-16-i686-Live-Desktop.iso
>  umount: /var/tmp/edit-liveos-W2ZKFk/install_root/sys/fs/selinux/load: not
>  found
>  Traceback (most recent call last):
>   File "/usr/bin/edit-livecd", line 723, in <module>
>     sys.exit(main())
>   File "/usr/bin/edit-livecd", line 697, in main
>     editor.mount(LiveOS, cachedir = None)
>   File "/usr/bin/edit-livecd", line 251, in mount
>     os.symlink("../proc/mounts", self._instroot + "/etc/mtab")
>  OSError: [Errno 17] File exists
>
>  I *think* that this is because self._instroot is set to None in class
>  LiveImageEditor(LiveImageCreator):, and does not appear to be reassigned.
>
>  Should the f16 livecd-tools version of edit-livecd work and are there any
>  particular options/configurations that I must set to get it to work? Or
>  should I just install from somewhere else (I'd much rather not do that as
>  it will screw up the other dependencies on the box, but if necessary, I
>  could spin up a VM and do it on that.)
>
>  All help gratefully received.
>
>  Tim
>  --
>  
I'm working on new features for edit-livecd and my code has these changes
from the master branch that should address the bugs you've encountered.

           --Fred

commit 1f597357a172435554e322658d016ec64c709d25
Author: Frederick Grose <fgrose(a)sugarlabs.org&gt;
Date:   Sat Mar 31 19:07:01 2012 -0400

    Provide a force-selinux option for edit-livecd.

    Only symlink /proc/self/mounts if /etc/mtab does not exist.
    Bind mount /etc/resolv.conf to better support networking.

diff --git a/imgcreate/creator.py b/imgcreate/creator.py
index e09bdcf..1baf999 100644
--- a/imgcreate/creator.py
+++ b/imgcreate/creator.py
@@ -444,14 +444,14 @@ class ImageCreator(object):
                 os.symlink(src, self._instroot + dest)
         os.umask(origumask)

-    def __create_selinuxfs(self):
+    def __create_selinuxfs(self, force=False):
         if not os.path.exists(self.__selinux_mountpoint):
             return

         arglist = ["/bin/mount", "--bind", "/dev/null",
self._instroot +
self.__selinux_mountpoint + "/load"]
         subprocess.call(arglist, close_fds = True)

-        if kickstart.selinux_enabled(self.ks):
+        if force or kickstart.selinux_enabled(self.ks):
             # label the fs like it is a root before the bind mounting
             arglist = ["/sbin/setfiles", "-F", "-r",
self._instroot,
selinux.selinux_file_context_path(), self._instroot]
             subprocess.call(arglist, close_fds = True)
@@ -463,12 +463,13 @@ class ImageCreator(object):
                 subprocess.call(arglist, close_fds = True)

     def __destroy_selinuxfs(self):
-        if not os.path.exists(self.__selinux_mountpoint):
-            return
+        """If the system was running SELinux, clean up our
lies."""
+
+        selinux_load = self._instroot + self.__selinux_mountpoint + '/load'
+        if os.path.exists(selinux_load):
+            arglist = ["/bin/umount", selinux_load]
+            subprocess.call(arglist, close_fds=True)

-        # if the system was running selinux clean up our lies
-        arglist = ["/bin/umount", self._instroot +
self.__selinux_mountpoint + "/load"]
-        subprocess.call(arglist, close_fds = True)

     def mount(self, base_on = None, cachedir = None):
         """Setup the target filesystem in preparation for an install.
diff --git a/tools/edit-livecd b/tools/edit-livecd
index 948064b..4232051 100755
--- a/tools/edit-livecd
+++ b/tools/edit-livecd
@@ -241,14 +241,24 @@ class LiveImageEditor(LiveImageCreator):
         cachesrc = cachedir or (self._ImageCreator__builddir +
"/yum-cache")
         makedirs(cachesrc)

-        for (f, dest) in [("/sys", None), ("/proc", None),
-                          ("/dev/pts", None), ("/dev/shm", None),
-                          (cachesrc, "/var/cache/yum")]:
-            self._ImageCreator__bindmounts.append(BindChrootMount(f,
self._instroot, dest))
-
+        bindmounts = [('/sys', None), ('/proc', None),
('/dev/pts', None),
+                      ('/dev/shm', None), (cachesrc, '/var/cache/yum'),
+                      ('/etc/resolv.conf', None)]
+        if self.force_selinux:
+            bindmounts += [(self._ImageCreator__selinux_mountpoint, None)]
+        for (f, dest) in bindmounts:
+            if os.path.exists(f):
+                self._ImageCreator__bindmounts.extend([BindChrootMount(f,
+                                                    self._instroot, dest)])
+            else:
+                logging.warn("Skipping (%s, %s) because source doesn't "
+                             "exist." % (f, dest))
         self._do_bindmounts()
-
-        os.symlink("../proc/mounts", self._instroot + "/etc/mtab")
+        if self.force_selinux:
+            self._ImageCreator__create_selinuxfs(force=True)
+        if not os.path.exists('/etc/mtab'):
+            os.symlink('/proc/self/mounts', os.path.join(self._instroot,
+                       'etc', 'mtab'))

         self.__copy_img_root(base_on)
         self._brand(self._builder)
@@ -545,6 +555,7 @@ def parse_options(args):
        %prog [-n=<name>]
                       [-o <output>]
                       [-k <kickstart-file>]
+                      [-f, --force-selinux]
                       [-s <script.sh>]
                       [-t <tmpdir>]
                       [-e <excludes>]
@@ -568,6 +579,10 @@ def parse_options(args):
     parser.add_option("-k", "--kickstart", type="string",
dest="kscfg",
                       help="Path or url to kickstart config file")

+    parser.add_option("-f", "--force-selinux",
action="store_true",
+                      dest="force_selinux", default=False,
+                      help='Force setting SELinux attributes on install
root.')
+
     parser.add_option("-s", "--script", type="string",
dest="script",
                       help="specify script to run chrooted in the LiveOS "
                            "fsimage")
@@ -677,6 +692,7 @@ def main():
     editor._exclude = options.exclude
     editor._exclude_file = options.exclude_file
     editor._include = options.include
+    editor.force_selinux = options.force_selinux
     editor.clone = options.clone
     editor.tmpdir = options.tmpdir
     editor._builder = options.builder

[Tim Coote]

Thanks, Fred.

Note that this change to edit-livecd causes a clash with the other -f abbreviation. (+ the
one that actually adds the option).

Other than that, the patch has certainly moved me on a lot.

Tim
>  +                      [-f, --force-selinux]

[Frederick Grose]

On Sun, Apr 1, 2012 at 5:47 PM, Tim Coote
<tim+fedoraproject.org(a)coote.org&gt;wrote:

>  Thanks, Fred.
>
>  Note that this change to edit-livecd causes a clash with the other -f
>  abbreviation. (+ the one that actually adds the option).
>
>  Other than that, the patch has certainly moved me on a lot.
>
>  Tim
>  > +                      [-f, --force-selinux]
>  
Oh yeah, I forgot about the -f, --exclude-file option for a rsync root
filesystem copy.
My yet-to-be-posted new version uses a device mapper mirror copy to replace
the rsync dependency, since rsync 3.0.8 introduced a bug with
xattributes[1].

1. http://lists.fedoraproject.org/pipermail/livecd/2011-April/006736.html

Brian could substitute [-S, --force-SELinux] to keep things unique, if he
likes the patch.

           --Fred