[PATCH][linux-snap][xenial][master] Copy host trusted.gpg keyring into the chroot

[Dimitri John Ledkov]

Launchpad xenial snap builds now have ubuntu-esm repositories
enabled. And now apt-get -y update started to produce error since the
GPG keys of the sources.list from the host, are not available in the
chroot. Fix this by copying the host trusted.gpg keyring into the
chroot.

Signed-off-by: Dimitri John Ledkov <xnox at ubuntu.com>
---

 This patch is for
 lp:~ubuntu-kernel/ubuntu/+source/linux-snap/+git/xenial -b master

 This patch is needed for the upcomming xenial ESM kernel snap builds,
 and enables building public ESM kernel snaps using kernels from
 ~ubuntu-esm/esm-infra-security in launchpad.

 https://code.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux-snap/+git/xenial/+ref/master

 This change & fix has been tested at
 https://launchpad.net/~xnox/+snap/xnox-pc-esm
 
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index 453c027..6f64547 100644
--- a/Makefile
+++ b/Makefile
@@ -82,6 +82,7 @@ prepare-chroot:
 	# already added there. This does not matter as long as adding the
 	# key will not require installing some additional package.
 	cp /etc/apt/sources.list chroot/etc/apt/sources.list
+	cp /etc/apt/trusted.gpg chroot/etc/apt/trusted.gpg.d/host-trusted.gpg
 	echo "deb http://ppa.launchpad.net/snappy-dev/image/ubuntu $(RELEASE) main" >> chroot/etc/apt/sources.list
 
 	# install all updates
-- 
2.27.0