#!/bin/bash
# This script has a bunch of GCE-related functions:
# ./gce.sh setup -  starts two VMs on GCE and configures them to run our integration tests
# . ./gce.sh; ./run_all.sh - set a bunch of environment variables for the tests
# ./gce.sh destroy - tear down the VMs
# ./gce.sh make_template - make a fresh VM template; update TEMPLATE_NAME first!

set -ex

KEY_FILE=/tmp/gce_private_key.json
SSH_KEY_FILE=$HOME/.ssh/gce_ssh_key
PROJECT=${PROJECT:-positive-cocoa-90213}
IMAGE=ubuntu-14-04
ZONE=us-central1-a
NUM_HOSTS=2

# Setup authentication
gcloud auth activate-service-account --key-file $KEY_FILE
gcloud config set project $PROJECT

function vm_names {
	local names=
	for i in $(seq 1 $NUM_HOSTS); do
		names="twilkie-test-$i $names"
	done
	echo "$names"
}

# Delete all vms in this account
function destroy {
	names="$(vm_names)"
	for i in {0..10}; do
		# gcloud instances delete can sometimes hang.
		case  $(set +e; timeout 60s /bin/bash -c "gcloud compute instances delete --zone $ZONE -q $names  >/dev/null 2>&1 || true"; echo $?) in
			0)
				return 0
				;;
			124)
				# 124 means it timed out
				break
				;;
			*)
				return 1
		esac
	done
}

function external_ip {
	gcloud compute instances list $1 --format=yaml | grep "^    natIP\:" | cut -d: -f2 | tr -d ' '
}

function internal_ip {
	gcloud compute instances list $1 --format=yaml | grep "^  networkIP\:" | cut -d: -f2 | tr -d ' '
}

function try_connect {
	for i in {0..10}; do
		ssh -t $1 true && return
		sleep 2
	done
}

function install_on {
	name=$1
	otherpeers=$2
	ssh -t $name sudo bash -x -s <<EOF
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9;
echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list;
apt-get update -qq;
apt-get install -q -y --force-yes --no-install-recommends lxc-docker ethtool emacs23-nox git make binutils mercurial libpcap-dev gcc;
usermod -a -G docker vagrant;
echo 'DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375"' >> /etc/default/docker;
service docker restart;
wget -q https://storage.googleapis.com/golang/go1.4.2.linux-amd64.tar.gz;
tar -C /usr/local -xzf go1.4.2.linux-amd64.tar.gz;
/usr/local/go/bin/go clean -i net
/usr/local/go/bin/go install -tags netgo std
EOF
	ssh -t $name bash -x -s <<EOF
echo "export PATH=$PATH:/usr/local/go/bin:~/bin" >>~/.profile
echo "export GOPATH=$HOME" >>~/.profile
. ~/.profile
mkdir -p ~/src/github.com/weaveworks
cd ~/src/github.com/weaveworks
git clone http://github.com/weaveworks/weave.git
cd weave
make
cp weave ~/bin
weave launch $otherpeers
EOF

}

# Create new set of VMS
function setup {
	destroy
	names="$(vm_names)"
	gcloud compute instances create $names --image $IMAGE --zone $ZONE
	gcloud compute config-ssh --ssh-key-file $SSH_KEY_FILE

	for name in $names; do
		hostname="$name.$ZONE.$PROJECT"
		# Add the remote ip to the local /etc/hosts
		sudo -- sh -c "echo \"$(external_ip $name) $hostname\" >>/etc/hosts"
		try_connect $hostname

		# Add the local ips to the remote /etc/hosts
		otherpeers=""
		for othername in $names; do
			otherip="$(internal_ip $othername)"
			otherpeers="$otherip $otherpeers"
			entry="$otherip $othername.$ZONE.$PROJECT"
			ssh -t "$hostname" "sudo -- sh -c \"echo \\\"$entry\\\" >>/etc/hosts\""
		done

		install_on $hostname "$otherpeers"
	done

    for name in $names; do
        hostname="$name.$ZONE.$PROJECT"
        ssh -t $hostname bash -x -s <<EOF
. ~/.profile
cd ~/src/github.com/weaveworks
git clone http://github.com/weaveworks/scope.git
cd scope
make deps
make
./scope launch
EOF
    done
}

function hosts {
	hosts=
	args=
	for name in $(vm_names); do
		hostname="$name.$ZONE.$PROJECT"
		hosts="$hostname $hosts"
		args="--add-host=$hostname:$(internal_ip $name) $args"
	done
	export SSH=ssh
	export HOSTS="$hosts"
	export WEAVE_DOCKER_ARGS="$args"
}

case "$1" in
setup)
	setup
	;;

hosts)
	hosts
	;;

destroy)
	destroy
	;;
esac