Ubuntu Core image for the staging Snap Store

staging-image.sh

# Create an Ubuntu core image with a custom snapd that talks to the staging Snap Store.
#
# LXD-based alternative:
#     https://gist.github.com/maxiberta/5fb47645b0d32137e13f5046ff330eb6

set -ex

tmp=$(mktemp -d)
cd "$tmp"

export GOPATH=$(pwd)
export PATH=$GOPATH/bin:$PATH

# get snapd source
git clone -b release/2.39 https://github.com/snapcore/snapd src/github.com/snapcore/snapd
go get -u github.com/kardianos/govendor
cd src/github.com/snapcore/snapd
govendor sync
cd -

# build binaries with staging keys
go build -tags withstagingkeys -o snap-stg github.com/snapcore/snapd/cmd/snap
go build -tags withstagingkeys -o snapd-stg github.com/snapcore/snapd/cmd/snapd

# download and unpack core snap
snap download core
sudo unsquashfs core_*.snap

# put binaries in place
sudo ls -l squashfs-root/usr/bin/snap squashfs-root/usr/lib/snapd/snapd
sudo cp snap-stg squashfs-root/usr/bin/snap
sudo cp snapd-stg squashfs-root/usr/lib/snapd/snapd

# customize environment
sudo su -c 'echo "SNAPPY_USE_STAGING_STORE=1" >> squashfs-root/etc/environment'
sudo su -c 'echo "SNAPD_DEBUG_HTTP=7" >> squashfs-root/etc/environment'
sudo su -c 'echo "SNAPPY_TESTING=1" >> squashfs-root/etc/environment'

# repack
sudo snapcraft pack ./squashfs-root

# get staging model
SNAPPY_USE_STAGING_STORE=1 ./snap-stg known --remote model series=16 model=pc-amd64 brand-id=canonical > pc-amd64.model

# build image using modified core snap and just built snap command (requires recent ubuntu-image)
SNAPPY_USE_STAGING_STORE=1 UBUNTU_IMAGE_SNAP_CMD=$PWD/snap-stg /usr/bin/ubuntu-image snap -O . --snap core_16-*.snap pc-amd64.model

# run image
echo DONE! Run with:
echo "  kvm -m 512 -netdev user,id=mynet0,hostfwd=tcp::3322-:22 -device virtio-net-pci,netdev=mynet0 -drive file=$tmp/pc.img,format=raw --snapshot"

# After initial configuration, SSH to the instance
# ssh -p 3322 -o "StrictHostKeyChecking no" -o "UserKnownHostsFile /dev/null" <sso-user-name>@localhost