#!/usr/bin/env bash
# Copyright 2021 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Usage:
#
# To get an interactive shell for development:
#   ./tools/dev_container
#
# To run a command in the container, e.g. to run presubmits:
#   ./tools/dev_container ./tools/presubmit
#
# The state of the container (including build artifacts) are preserved between
# calls. To stop the container call:
#   ./tools/dev_container --stop
#
# The dev container can also be called with a fresh container for each call that
# is cleaned up afterwards (e.g. when run by Kokoro):
#
#   ./tools/dev_container --hermetic CMD

set -e
cd "$(dirname "${BASH_SOURCE[0]}")/.."

# Allow to override the container CLI tool, similar to the Makefile. Try
# "docker" first and fall back to "podman".
DOCKER=${DOCKER:-$(which docker || which podman)}

# Name to identify the running crosvm dev container
CONTAINER_NAME=crosvm_dev

IMAGE_VERSION=$(cat tools/impl/dev_container/version)

# Enable interactive mode when running in an interactive terminal.
TTY_ARGS=()
if [ -t 1 ]; then
    TTY_ARGS+=(
        --interactive
        --tty
    )
fi

# Podman will not share devices when `--privileged` is specified
PRIV_ARGS=()
if [ "${DOCKER}" != "${podman}" ]; then
    PRIV_ARGS+=(
        --privileged
    )
fi

DOCKER_ARGS=(
    "${TTY_ARGS[@]}"
    --volume "$(pwd):/workspace:rw"
    --device "/dev/kvm"
    --volume "/dev/log:/dev/log"
    --device "/dev/net/tun"
    --device "/dev/vhost-net"
    --device "/dev/vhost-vsock"
    --mount "type=tmpfs,destination=/tmp"
    "${PRIV_ARGS[@]}"
    "gcr.io/crosvm-packages/crosvm_dev:$IMAGE_VERSION"
)

docker_run_detached() {
    "${DOCKER}" run \
        --detach --name "${CONTAINER_NAME}" \
        "${DOCKER_ARGS[@]}" >/dev/null
}

docker_run() {
    "${DOCKER}" run --rm "${DOCKER_ARGS[@]}" "$@"
}

get_container_id() {
    "${DOCKER}" ps -q -f name="${CONTAINER_NAME}"
}

docker_exec() {
    if [[ $# -gt 0 ]]; then
        cmd=("$@")
    else
        cmd=(/bin/bash)
    fi
    "${DOCKER}" exec "${TTY_ARGS[@]}" "$(get_container_id)" "${cmd[@]}"
}

main() {
    if [[ "$1" == "--stop" ]]; then
        if [ -n "$(get_container_id)" ]; then
            "${DOCKER}" rm -f "$(get_container_id)" >/dev/null
        fi
        exit
    fi

    if [[ "$1" == "--hermetic" ]]; then
        shift
        docker_run "$@"
    else
        if [ -z "$(get_container_id)" ]; then
            docker_run_detached
        fi
        docker_exec "$@"
    fi

}

main "$@"