kernel.py: put submenu name in 01_ceph_kernel if necessary

We had been writing 01_ceph_kernel with the kernel title, and
relying on the fact that grub.cfg would never have submenus in it
(implemented by a hack to /etc/grub.d/10_linux which neutered its
submenu creation).  However, that hack was modifying a package file,
and got in the way of later apt commands.  Rather than doing it
that way, this divines the title of the submenu and sets the
default variable to "submenu>kernel", which works to select the
desired kernel.

It depends on there being only one level of submenu, and on the
format of the menuentry and submenu commands, dictated by grub2.
None of this is likely to work at all outside Ubuntu.

Fixes: #4496
Signed-off-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>

diff --git a/teuthology/task/kernel.py b/teuthology/task/kernel.py
index a5b913381fbf24498707c4bb212068c160e70a48..9cb0d9e34ce4fe50daa12531f28175684f62a235 100644 (file)
--- a/teuthology/task/kernel.py
+++ b/teuthology/task/kernel.py
@@ -2,6 +2,7 @@ from cStringIO import StringIO
 
 import logging
 import re
+import shlex
 
 from teuthology import misc as teuthology
 from ..orchestra import run
@@ -219,12 +220,19 @@ def install_and_reboot(ctx, config):
         (role_remote,) = ctx.cluster.only(role).remotes.keys()
         proc = role_remote.run(
             args=[
+                # install the kernel deb
                 'sudo',
                 'dpkg',
                 '-i',
                 '/tmp/linux-image.deb',
-                run.Raw('&&'),
-                # and now extract the actual boot image name from the deb
+                ],
+            )
+
+        # collect kernel image name from the .deb
+        cmdout = StringIO()
+        proc = role_remote.run(
+            args=[
+                # extract the actual boot image name from the deb
                 'dpkg-deb',
                 '--fsys-tarfile',
                 '/tmp/linux-image.deb',
@@ -237,12 +245,53 @@ def install_and_reboot(ctx, config):
                 '--',
                 './boot/vmlinuz-*',
                 run.Raw('|'),
-                # we can only rely on mawk being installed, so just call it explicitly
-                'mawk',
-                # and use the image name to construct the content of
-                # the grub menu entry, so we can default to it;
-                # hardcoded to assume Ubuntu, English, etc.
-                r'{sub("^\\./boot/vmlinuz-", "", $6); print "cat <<EOF\n" "set default=\"Ubuntu, with Linux " $6 "\"\n" "EOF"}',
+                'sed',
+                r'-e s;.*\./boot/vmlinuz-;;',
+            ],
+            stdout = cmdout,
+            )
+        kernel_title = cmdout.getvalue().rstrip()
+        cmdout.close()
+        log.info('searching for kernel {}'.format(kernel_title))
+
+        # look for menuentry for our kernel, and collect any
+        # submenu entries for their titles.  Assume that if our
+        # kernel entry appears later in the file than a submenu entry,
+        # it's actually nested under that submenu.  If it gets more
+        # complex this will totally break.
+        cmdout = StringIO()
+        proc = role_remote.run(
+            args=[
+                'egrep',
+                '(submenu|menuentry.*' + kernel_title + ').*{',
+                '/boot/grub/grub.cfg'
+               ],
+            stdout = cmdout,
+            )
+        submenu_title = ''
+        default_title = ''
+        for l in cmdout.getvalue().split('\n'):
+            fields = shlex.split(l)
+            if len(fields) >= 2:
+                command, title = fields[:2]
+                if command == 'submenu':
+                    submenu_title = title + '>'
+                if command == 'menuentry':
+                    if title.endswith(kernel_title):
+                        default_title = title
+                        break
+        cmdout.close()
+        log.info('submenu_title:{}'.format(submenu_title))
+        log.info('default_title:{}'.format(default_title))
+
+        proc = role_remote.run(
+            args=[
+                # use the title(s) to construct the content of
+                # the grub menu entry, so we can default to it.
+                '/bin/echo',
+                '-e',
+                r'cat <<EOF\nset default="' + submenu_title + \
+                    default_title + r'"\nEOF\n',
                 # make it look like an emacs backup file so
                 # unfortunately timed update-grub runs don't pick it
                 # up yet; use sudo tee so we are able to write to /etc
@@ -264,6 +313,7 @@ def install_and_reboot(ctx, config):
                 '--',
                 '/etc/grub.d/01_ceph_kernel.tmp~',
                 '/etc/grub.d/01_ceph_kernel',
+                # update grub again so it accepts our default
                 run.Raw('&&'),
                 'sudo',
                 'update-grub',