Set a default locale of C.UTF-8 in the cloud images.

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.450) UNRELEASED; urgency=medium
+
+  [ Steve Langasek ]
+  * Set a default locale of C.UTF-8 in the cloud images.
+
+ -- Dimitri John Ledkov <xnox@ubuntu.com>  Fri, 18 Aug 2017 09:11:42 +0100
+
 livecd-rootfs (2.449) artful; urgency=medium
 
   [ Balint Reczey ]

live-build/ubuntu-cpc/hooks/999-cpc-fixes.chroot

@@ -59,6 +59,12 @@ _xchroot "${rootd}" sh -c 'rm -f /etc/ssh/ssh_host_[rd]sa_key*'
 ## --------------
 _xchroot "${rootd}" locale-gen en_US.utf8
 
+## --------------
+# We continue to pre-generate en_US.UTF-8 locale above, but the default locale
+# should be C.UTF-8 for 17.10 and later.  For earlier releases, cloud-init may
+# override this.
+echo LANG="C.UTF-8" > "${rootd}/etc/default/locale"
+
 ## --------------
 # set cloud-init to be on
 values="NoCloud, ConfigDrive, AltCloud, OVF, MAAS, Ec2, None"