#!/bin/bash

##########################################
# WARNING WARNING WARNING WARNING 
#
# This script is an example to start a new AGL container
#
# You should customize it to fit your environment and in particular 
# adjust the paths and permissions where needed.
# 
# Note that sharing volumes with the host system is not mandatory: it
# was just added for performance reasons: building from a SSD is
# just faster than using the container filesystem: that's why /xdt is 
# mounted from there. The same applies to ~/mirror and ~/share, which are 
# just 2 convenient folders to store reference build caches (used in
# prepare_meta script)
#
##########################################

CURDIR=$(cd $(dirname $0) && pwd -P)
PREFIX=agl-worker
DEFIMAGE=$(make -s -C $CURDIR/.. show-image)
OCCUPIED_ID=$(docker ps -a -f name=${PREFIX} --format "{{.Names}}" | grep -oE "[0-9]" | sort -n | sed ':a;N;$!ba;s/\n/ /g')
BOOTSRV=""
ID=""
IMAGE=""
DOCKER_USER="devel"
DOCKER_UID="1664"

function usage() {
	echo "Usage: $(basename $0) <instance ID> [image name] [--enable-boot-srv]"  >&2
	echo "Instance ID must be 0 or a positive integer (1,2,...)" >&2
	echo "Image name is optional: 'make show-image' is used by default to get image" >&2
	echo "--enable-boot-srv: Enable binding tftp/nbd port." >&2
	echo "Default image: $DEFIMAGE" >&2
	exit 1
}

function updateContainerUid () {
    echo -n "Setup docker user and group id to match yours "

    res=3
    max=30
    count=0
    while [ $res -ne 1 ] && [ $count -le $max ]; do
        sleep 1
        docker exec ${NAME} bash -c "loginctl user-status $DOCKER_USER |grep sd-pam" 2>/dev/null 1>&2
        res=$?
        echo -n "."
        count=$((count + 1));
    done

    echo -n "."

    # Set uid
    if docker exec -t ${NAME} bash -c "id $(id -u)" > /dev/null 2>&1 && \
            [ "$(id -u)" != "$DOCKER_UID" ]; then
        echo "Cannot set docker $DOCKER_USER user id to your id: conflicting id $(id -u) !"
        exit 1
    fi
    docker exec -t ${NAME} bash -c "usermod -u $(id -u) $DOCKER_USER" || exit 1
    echo -n "."

    # Set gid
    if docker exec -t ${NAME} bash -c "grep $(id -g) /etc/group" > /dev/null 2>&1; then
        docker exec -t ${NAME} bash -c "usermod -g $(id -g) $DOCKER_USER" || exit 1
    else
        docker exec -t ${NAME} bash -c "groupmod -g $(id -g) $DOCKER_USER" || exit 1
    fi
    echo -n "."

    docker exec -t ${NAME} bash -c "chown -R $DOCKER_USER:$DOCKER_USER /home/$DOCKER_USER" || exit 1
    echo -n "."
    docker exec -t ${NAME} bash -c "chown -R $DOCKER_USER:$DOCKER_USER $XDTDIR_MAPPED"
    echo "."
}

function setupContainerSsh () {
    echo "Copying your SSH identity to container $NAME"
    echo -n Waiting for the ssh service to come up in the container ...
    res=3
    max=30
    count=0
    while [ $res -ne 0 ] && [ $count -le $max ]; do
        sleep 1
        docker exec ${NAME} bash -c "systemctl status ssh" 2>/dev/null 1>&2 
        res=$?
        echo -n "."
        count=$(expr $count + 1);
    done
    echo

    ssh-keygen -R [$(hostname)]:$SSH_PORT -f ~/.ssh/known_hosts
    docker exec ${NAME} bash -c "mkdir -p /home/$DOCKER_USER/.ssh"
    docker cp ~/.ssh/id_rsa.pub ${NAME}:/home/$DOCKER_USER/.ssh/authorized_keys
    docker exec ${NAME} bash -c "chown $DOCKER_USER:$DOCKER_USER -R /home/$DOCKER_USER/.ssh ;chmod 0700 /home/$DOCKER_USER/.ssh;chmod 0600 /home/$DOCKER_USER/.ssh/*"
    ssh -o StrictHostKeyChecking=no -p $SSH_PORT $DOCKER_USER@$(hostname) exit
}

while [ $# -ne 0 ]; do
	case $1 in 
		-h|--help|"")
			usage
			;;
		--enable-boot-srv)
			BOOTSRV="TRUE"; 
			shift
			;;
		*)
			if [ -z "${ID}" ] ; then 
				ID=$1
				shift
			elif [ -z "${IMAGE}" ] ; then 
				IMAGE=$1
				shift
			else
				usage
			fi
			;;
	esac
done

if [ -z "${IMAGE}" ] ; then 
	IMAGE=${DEFIMAGE}
fi

USER=$(id -un)
echo "Using instance ID #$ID (user $(id -un))"

NAME=${PREFIX}-$(hostname|cut -f1 -d'.')-$ID-$USER

for n in $(docker ps -a -f name=${PREFIX} --format "{{.Names}}")
do
	if [ $NAME = $n ]
	then
		echo "This id is already taken."
		echo "Please choose another one."
		echo "ids already in use: ${OCCUPIED_ID}"
		exit 2
	fi
done

MIRRORDIR=$HOME/ssd/localmirror_$ID
XDTDIR=$HOME/ssd/xdt_$ID
SHAREDDIR=$HOME/ssd/share

MIRRORDIR_MAPPED=/home/$DOCKER_USER/mirror
XDTDIR_MAPPED=/xdt
SHAREDDIR_MAPPED=/home/$DOCKER_USER/share

SSH_PORT=$((2222 + ID))
WWW_PORT=$((8000 + ID))
BOOT_PORT=69
NBD_PORT=10809

mkdir -p $MIRRORDIR $XDTDIR $SHAREDDIR

if [ -n "${BOOTSRV}" ] ; then
	BOOTSRV_CONFIG="--publish=${BOOT_PORT}:69/udp --publish=${NBD_PORT}:10809";
fi

docker run \
	--publish=${SSH_PORT}:22 \
	--publish=${WWW_PORT}:8000 \
	${BOOTSRV_CONFIG} \
	--detach=true \
	--hostname=$NAME --name=$NAME \
	--privileged -v /sys/fs/cgroup:/sys/fs/cgroup:ro \
	-v $MIRRORDIR:$MIRRORDIR_MAPPED \
	-v $SHAREDDIR:$SHAREDDIR_MAPPED \
	-v $XDTDIR:$XDTDIR_MAPPED \
	-it $IMAGE

if [ $? -ne 0 ]; then
	echo "Failed to run docker"
	exit 1
fi

setupContainerSsh
updateContainerUid

echo "You can now login using:"
echo "   ssh -p $SSH_PORT $DOCKER_USER@$(hostname)"