launchpad-reviewers team mailing list archive

["Jeroen T. Vermeulen" <jtv@xxxxxxxxxxxxx>]

Jeroen T. Vermeulen has proposed merging lp:~jtv/maas/pkg-bug-1050033 into lp:~maas-maintainers/maas/packaging.

Commit message:
Migrate pre-Quantal ephemeral images from linux/initrd pairs to kernel/initrd.gz pairs.

Requested reviews:
  Launchpad code reviewers (launchpad-reviewers)
Related bugs:
  Bug #1050033 in MAAS: "maas-import-pxe-files has copying errors after package upgrade"
  https://bugs.launchpad.net/maas/+bug/1050033

For more details, see:
https://code.launchpad.net/~jtv/maas/pkg-bug-1050033/+merge/128572

This was blocking upgrades from Precise to Quantal: the "kernel" and "initrd.gz" files from downloadd ephemeral images were not found, because the older version of the maas-import-ephemerals script downloaded "linux" and "initrd" files instead.

The branch you see here does some in-place migration: if there's a linux file but no kernel file, hardlink the latter to the former.  If there's an initrd file but no initrd.gz, gzip the former to the latter.  In both cases, the existing files are left in place (gzip's -c option has this effect) and no existing files are overwritten.

While trying this change I found that the initrd files were actually already gzipped, but that's OK: gzipping it again won't double-compress it.  Instead the command will produce essentially the same file, except the name/timestamp are saved into the file.  (You can disable that, but I didn't want to; the name works out correctly and keeping the original file's timestamp is likely to be clearer in post-mortem investigations than using the time of compression.)  I verified that uncompressing the initrd.gz produces an exact copy of the initrd that went in.


Jeroen
-- 
https://code.launchpad.net/~jtv/maas/pkg-bug-1050033/+merge/128572
Your team Launchpad code reviewers is requested to review the proposed merge of lp:~jtv/maas/pkg-bug-1050033 into lp:~maas-maintainers/maas/packaging.

=== modified file 'debian/maas-region-controller.postinst'
--- debian/maas-region-controller.postinst	2012-10-05 04:26:58 +0000
+++ debian/maas-region-controller.postinst	2012-10-08 19:18:44 +0000
@@ -133,6 +133,32 @@
 	fi
 }
 
+# If ephemeral image directory $1 contains an initrd but not an initrd.gz,
+# create the latter.  If it contains a "kernel" but not a "linux," create
+# the latter.
+migrate_ephemeral_image() {
+	local image="$1"
+	if [ -d "$image" ]; then
+		if [ -f "$image/initrd" ] && [ ! -f "$image/initrd.gz" ]; then
+			gzip -c -- "$image/initrd" >"$image/initrd.gz"
+		fi
+		if [ -f "$image/kernel" ] && [ ! -f "$image/linux" ]; then
+			ln -- "$image/kernel" "$image/linux"
+		fi
+	fi
+}
+
+# Pre-Quantal versions of maas-import-ephemerals imported boot images with a
+# "kernel" and "initrd."  Newer versions expect to find "linux" and
+# "initrd.gz."  Produce those from the existing files.
+migrate_ephemeral_images() {
+	if [ -d /var/lib/maas/ephemeral/precise/ephemeral ]; then
+		for image in /var/lib/maas/ephemeral/precise/ephemeral/*/*/; do
+			migrate_ephemeral_image "$image"
+		done
+	fi
+}
+
 configure_maas_squid_deb_proxy() {
 	local ipaddr="$1"
 
@@ -310,6 +336,8 @@
 
 	maas_sync_migrate_db
 
+	migrate_ephemeral_images
+
 fi
 
 restart_apache2