Generate the default en_US locale

The default locale set by cloud-init is now generated to prevent the
warning printed when the user is logged in.

Closes-Bug: 1440728
Change-Id: I2faff6c9d3ab8bb5f66d58e77bcf37f186bf501d

elements/debian/root.d/08-debootstrap

@@ -105,6 +105,10 @@ auto eth0
 iface eth0 inet dhcp
 EOF
 
+    # generate the default en_US locale
+    sudo sed -i -e "0,/^[# ]*en_US.UTF-8 UTF-8 *$/ s/^[# ]*en_US.UTF-8 UTF-8 *$/en_US.UTF-8 UTF-8/" ${TARGET_ROOT}/etc/locale.gen
+    sudo chroot ${TARGET_ROOT} dpkg-reconfigure -f noninteractive locales
+
     echo Caching debootstrap result in $DEBOOTSTRAP_TARBALL
     sudo tar -C $TARGET_ROOT -zcf $DEBOOTSTRAP_TARBALL --exclude='./tmp/*' .
 fi