dr

#!/usr/bin/env bash

# Copyright (c) 2021 Microchip Technology Inc. and its subsidiaries.
# SPDX-License-Identifier: MIT

unset MCHP_DOCKER_DEBUG
unset MCHP_DOCKER_PULL
unset MCHP_DOCKER_VERBOSE
unset MCHP_DOCKER_INTERACTIVE
unset MCHP_DOCKER_NO_FILE
unset MCHP_DOCKER_TOP

script=$(basename $0)
denv=".docker.env"
top=$(pwd)
hostname=dr-$RANDOM-$(hostname)

usage() {
    echo "$script usage:"
    echo "  $script [options] [command]"
    echo ""
    echo "Options:"
    echo "  -d  Debug mode. Specify image by \"name:latest\" and ignore tag and digest"
    echo "      even if they are present in $denv. This way you don't have to update"
    echo "      tag and digest after each docker build in order to test the image."
    echo "  -h  Show this help."
    echo "  -p  Pull docker image unconditionally using name:tag (ignore digest)."
    echo "  -n  Ignore $denv file and use environment variables."
    echo "  -t  Overwrite the top folder, can be used only with -n option."
    echo "  -v  Verbose mode."
    echo ""
    echo "Command:"
    echo "  Optional command to run - default command depends on docker image."
    echo ""
    echo "File $denv:"
    echo "  This file must be present somewhere between the current directory and"
    echo "  the root of the filesystem (\"/\") when the $script script is used."
    echo "  It determines which docker image to run and will eventually pull it"
    echo "  if not found in the local cache."
    echo ""
    echo "  The following variables are supported:"
    echo "    MCHP_DOCKER_NAME    - The name of the repository (required)."
    echo "    MCHP_DOCKER_TAG     - The tag (optional). Default is \"latest\"."
    echo "    MCHP_DOCKER_DIGEST  - The digest (optional). If present, the image is"
    echo "                          identified as \"name@digest\". If missing or -d is "
    echo "                          given the docker image is identified as \"name:tag\"."
    echo "    MCHP_DOCKER_OPTIONS - Extra options to the docker run command (optional)."
    echo ""
    echo "  The $denv file is sourced in a bash envirinment and it is possible to do all"
    echo "  kind of processing/verfication and eventually call exit 1 on errors."
    echo ""
    echo "  It is possible to define one or more variables and transfer them into the"
    echo "  container by adding an -e option in MCHP_DOCKER_OPTIONS"
    echo ""
    echo "The Docker container is run interactively (-it) and is removed on exit (--rm)."
    echo "The directory containing the $denv file is mounted 1:1 inside the container"
    echo "and the current directory inside the container will be the same as outside."
    exit 1
}

# Only echo if verbose
vecho() { if [[ -v MCHP_DOCKER_VERBOSE ]]; then echo "$@"; fi }

while getopts ":dhpvnt:" opt; do
    case $opt in
	d)
	    MCHP_DOCKER_DEBUG=1
	    ;;
	h)
	    usage
	    ;;
	p)
	    MCHP_DOCKER_PULL=1
	    ;;
	v)
	    MCHP_DOCKER_VERBOSE=1
	    ;;
	n)
	    MCHP_DOCKER_NO_FILE=1
	    ;;
        t)
	    MCHP_DOCKER_TOP=$OPTARG
            ;;
	\?)
	    echo "Invalid option: -$OPTARG" 1>&2
	    usage
	    ;;
    esac
done

shift $((OPTIND - 1))

if [[ -v MCHP_DOCKER_NO_FILE ]]; then
    if [[ -v MCHP_DOCKER_TOP ]]; then
        top="$(readlink -f "$MCHP_DOCKER_TOP")"
    fi
else
    unset MCHP_DOCKER_NAME
    unset MCHP_DOCKER_TAG
    unset MCHP_DOCKER_DIGEST
    unset MCHP_DOCKER_OPTIONS

    # Search for .docker.env from current directory and back to root directory "/"
    while [[ "$top" != "/" && ! -e "$top/$denv" ]]; do
        top="$(readlink -f "$top"/..)"
    done

    if [[ ! -f "$top/$denv" ]]; then
        echo "No $denv file found in parent directories" 1>&2
        exit 1
    fi

    source $top/$denv
fi

if [[ ! -v MCHP_DOCKER_NAME ]]; then
    echo "Docker image name not defined, check $top/$denv" 1>&2
    exit 1
fi

if [[ -v MCHP_DOCKER_DEBUG || ! -v MCHP_DOCKER_TAG ]]; then
    MCHP_DOCKER_TAG="latest"
fi

pull="${MCHP_DOCKER_NAME}:${MCHP_DOCKER_TAG}"

if [[ -v MCHP_DOCKER_PULL ]]; then
    echo "Pull $pull"
    docker pull "$pull"
fi

if [[ -v MCHP_DOCKER_DEBUG || ! -v MCHP_DOCKER_DIGEST ]]; then
    unset MCHP_DOCKER_DIGEST
    image="$pull"
    match="${MCHP_DOCKER_NAME}_${MCHP_DOCKER_TAG}"
    format="{{.Repository}}_{{.Tag}}"
else
    image="${MCHP_DOCKER_NAME}@${MCHP_DOCKER_DIGEST}"
    match="${MCHP_DOCKER_NAME}_${MCHP_DOCKER_TAG}_${MCHP_DOCKER_DIGEST}"
    format="{{.Repository}}_{{.Tag}}_{{.Digest}}"
fi

vecho "Top     : $top"
vecho "Name    : $MCHP_DOCKER_NAME"
vecho "Tag     : $MCHP_DOCKER_TAG"
vecho "Digest  : $MCHP_DOCKER_DIGEST"
vecho "Options : $MCHP_DOCKER_OPTIONS"
vecho "Pull    : $pull"
vecho "Image   : $image"
vecho "Match   : $match"
vecho "Format  : $format"
vecho "Command : $@"

# Check if the image is present in local cache.
# If not then pull image from hub.
docker images --format $format | grep -F --quiet $match
if [ $? -ne 0 ]; then
    docker pull $pull
    if [ $? -ne 0 ]; then
        echo "Failed to pull docker image $pull" 1>&2
        exit 1
    fi
    if [[ -v MCHP_DOCKER_DIGEST ]]; then
	# Check that the image just pulled via name:tag has the expected digest
	docker images --format $format | grep -F --quiet $match
	if [ $? -ne 0 ]; then
	    echo "Mismatch between tag and digest, check $top/$denv" 1>&2
	    exit 1
	fi
    fi
fi

if [[ -t 0 && -t 1 ]]; then
    MCHP_DOCKER_INTERACTIVE='-it' # We have tty's
fi

# $MCHP_DOCKER_IT      : Set to '-it' if run interactively
# --rm                 : Remove the container at exit
# -v                   : Mount everything from the directory where .docker.env is located.
# -w                   : Working directory inside the container is the same as outside.
# $MCHP_DOCKER_OPTIONS : User supplied options in .docker.env
args=(run $MCHP_DOCKER_INTERACTIVE --hostname $hostname --rm -v $top:$top -w $(pwd) $MCHP_DOCKER_OPTIONS)
# parse all the other MCHP_DOCKER_OPTIONS$i options, these contains white spaces
for i in $(seq 0 1024)
do
    combined=MCHP_DOCKER_OPTIONS${i}
    if [ ! -z "${!combined}" ]
    then
	var1=$(eval echo ${!combined} | cut -d '=' -f 1)
	var2=$(eval echo ${!combined} | cut -d '=' -f 2)
	args+=(-e ${var1}="${var2}")
    fi
done

# $image               : Docker image to run
args+=($image "$@")

vecho "docker ${args[@]}"
docker "${args[@]}"