container

#!/bin/bash

set -e
#set -x

NAME_BASE=hvac-demo

MY_DIR=$(dirname $0)

CONTAINER_NAME_FILE=$MY_DIR/.container-name

error() {
	echo "error: $@"
	exit 2
}

check_podman() {
	if which podman >/dev/null 2>&1; then
		if podman ps >/dev/null; then
			return 0
		else
			echo "podman installed but won't run, this is unusual"
		fi
	fi
	return 1
}

check_docker() {
	if which docker >/dev/null 2>&1; then
		if docker ps >/dev/null; then
			return 0
		else
			echo "docker installed but won't run, check groups"
		fi
	fi
	return 1
}

set_container_command() {
	# if the var is already set to an acceptable value, just use it
	case "$DOCKER" in
	docker|podman)
		if check_${DOCKER}; then
			echo "Using $DOCKER"
			return
		fi
	esac

	if check_podman; then
		DOCKER=podman
	elif check_docker; then
		DOCKER=docker
	else
		error "Please install docker or podman"
	fi

	echo "Using $DOCKER"
}

container_exists() {
	if [ -n "$CONTAINER_NAME" ]; then
		$DOCKER container inspect $CONTAINER_NAME >/dev/null 2>&1
	else
		false
	fi
}

get_container_name() {
	if [ -e $CONTAINER_NAME_FILE ]; then
		CONTAINER_NAME=$(cat $CONTAINER_NAME_FILE)
	else
		CONTAINER_NAME=""
	fi
}

make_container_name() {
	CONTAINER_NAME=${NAME_BASE}-$(date --iso)-${RANDOM}
	echo "$CONTAINER_NAME" >$CONTAINER_NAME_FILE
}

docker_run_container() {
	$DOCKER run -it --name $CONTAINER_NAME -v$PWD:/prj \
		-h $NAME_BASE \
		docker.io/debian:12 \
		/prj/scripts/container-main
}

podman_run_container() {
	podman run -it --name $CONTAINER_NAME -v$PWD:/prj \
		docker.io/debian:12 \
		/prj/scripts/container-main podman_main1 $USER $UID $(id -g)
	podman commit $CONTAINER_NAME ${CONTAINER_NAME}-base
	podman rm $CONTAINER_NAME
	podman run -it --name $CONTAINER_NAME -v$PWD:/prj \
		-h $NAME_BASE \
		--userns=keep-id \
		${CONTAINER_NAME}-base \
		/prj/scripts/container-main podman_main2
}

main() {
	set_container_command
	get_container_name
	if container_exists $CONTAINER_NAME; then
		$DOCKER start $CONTAINER_NAME >/dev/null
		$DOCKER attach $CONTAINER_NAME
		exit $?
	else
		make_container_name
		${DOCKER}_run_container
	fi
}

docker_delete_base() {
	# nothing to do here
	true
}

podman_delete_base() {
	$DOCKER image rm ${CONTAINER_NAME}-base
}

do_delete() {
	set_container_command
	get_container_name
	if container_exists $CONTAINER_NAME; then
		$DOCKER rm -f $CONTAINER_NAME
		${DOCKER}_delete_base
		rm $CONTAINER_NAME_FILE
	elif [ -n "$CONTAINER_NAME" ]; then
		echo "cleaning up dangling container name $CONTAINER_NAME"
		rm $CONTAINER_NAME_FILE
	else
		echo "nothing to do"
	fi
}

get_help() {
	echo "./container [--delete|--help]"
	echo "start, restart or delete a container for the demos"
}

cd $MY_DIR
case $1 in
"")
	main
	;;
--delete|--rm)
	do_delete
	;;
--help)
	get_help
	;;
*)
	error "unknown arguments $@"
	;;
esac