docker-pi-hole/build.sh

#!/bin/bash
set -e

# Usage function
usage() {
    echo "Usage: $0 [-l] [-f <ftl_branch>] [-c <core_branch>] [-w <web_branch>] [-t <tag>] [use_cache]"
    echo "Options:"
    echo "  -f,  --ftlbranch <branch>     Specify FTL branch (cannot be used in conjunction with -l)"
    echo "  -c,  --corebranch <branch>    Specify Core branch"
    echo "  -w,  --webbranch <branch>     Specify Web branch"
    echo "  -p,  --paddbranch <branch>    Specify PADD branch"
    echo "  -t,  --tag <tag>              Specify Docker image tag (default: pihole:local)"
    echo "  -l,  --local                  Use locally built FTL binary (requires src/pihole-FTL file)"
    echo "  use_cache                     Enable caching (by default --no-cache is used)"
    echo ""
    echo "If no options are specified, the following command will be executed:"
    echo "  docker buildx build src/. --tag pihole:local --load --no-cache"
    exit 1
}

# Set default values
TAG="pihole:local"
FTL_FLAG=false
USE_CACHE=false
CORE_FORK="pi-hole"
WEB_FORK="pi-hole"
PADD_FORK="pi-hole"

# Check if buildx is installed
docker buildx version >/dev/null 2>&1
if [ $? -ne 0 ]; then
    echo "Error: Docker buildx is required to build this image. For installation instructions, see:"
    echo "       https://github.com/docker/buildx#installing"
    exit 1
fi

# Function to check if a custom branch entered by the user is valid
check_branch_exists() {
    local repo=$1
    local branch=$2
    local fork=$3
    local url

    if [ "$repo" == "ftl" ]; then
        # Special case for FTL - we check for the binary instead of just the branch - in case it is not yet built.
        url="https://ftl.pi-hole.net/${branch}/pihole-FTL-amd64"
    else
        url="https://github.com/${fork}/${repo}/blob/${branch}/README.md"
    fi

    local http_code
    http_code=$(curl -sI --max-time 10 "$url" -o /dev/null -w "%{http_code}")
    if [ "${http_code}" -ne 200 ]; then
        echo "Error: $repo branch '$branch' not found. Exiting."
        exit 1
    fi
}

# Collect extra --build-arg values from flags
BUILD_ARGS=()

# Parse command line arguments
while [[ $# -gt 0 ]]; do
    key="$1"

    case $key in
    -l | --local)
        if [ ! -f "src/pihole-FTL" ]; then
            echo "File 'src/pihole-FTL' not found. Exiting."
            exit 1
        fi
        if [ "$FTL_FLAG" = true ]; then
            echo "Error: Both -l and -f cannot be used together."
            usage
        fi
        FTL_FLAG=true
        BUILD_ARGS+=(--build-arg "FTL_SOURCE=local")
        shift
        ;;
    -f | --ftlbranch)
        if [ "$FTL_FLAG" = true ]; then
            echo "Error: Both -l and -f cannot be used together."
            usage
        fi
        FTL_FLAG=true
        FTL_BRANCH="$2"
        check_branch_exists "ftl" "$FTL_BRANCH"
        BUILD_ARGS+=(--build-arg "FTL_BRANCH=$FTL_BRANCH")
        shift
        shift
        ;;
    -c | --corebranch)
        CORE_BRANCH="$2"
        check_branch_exists "pi-hole" "$CORE_BRANCH" "$CORE_FORK"
        BUILD_ARGS+=(--build-arg "CORE_BRANCH=$CORE_BRANCH")
        shift
        shift
        ;;
    -w | --webbranch)
        WEB_BRANCH="$2"
        check_branch_exists "web" "$WEB_BRANCH" "$WEB_FORK"
        BUILD_ARGS+=(--build-arg "WEB_BRANCH=$WEB_BRANCH")
        shift
        shift
        ;;
    -p | --paddbranch)
        PADD_BRANCH="$2"
        check_branch_exists "padd" "$PADD_BRANCH"
        BUILD_ARGS+=(--build-arg "PADD_BRANCH=$PADD_BRANCH")
        shift
        shift
        ;;
    -cf | --corefork)
        CORE_FORK="$2"
        BUILD_ARGS+=(--build-arg "CORE_FORK=$CORE_FORK")
        shift
        shift
        ;;
    -wf | --webfork)
        WEB_FORK="$2"
        BUILD_ARGS+=(--build-arg "WEB_FORK=$WEB_FORK")
        shift
        shift
        ;;
    -pf | --paddfork)
        PADD_FORK="$2"
        BUILD_ARGS+=(--build-arg "PADD_FORK=$PADD_FORK")
        shift
        shift
        ;;
    -t | --tag)
        TAG="$2"
        shift
        shift
        ;;
    use_cache)
        USE_CACHE=true
        shift
        ;;
    *)
        echo "Unknown option: $1"
        usage
        ;;
    esac
done

# Build the command as an array to avoid eval and shell injection
DOCKER_BUILD_CMD=(docker buildx build src/. --tag "${TAG}" --load)
[ "$USE_CACHE" = false ] && DOCKER_BUILD_CMD+=(--no-cache)
DOCKER_BUILD_CMD+=("${BUILD_ARGS[@]}")

# Execute the docker build command
echo "Executing command: ${DOCKER_BUILD_CMD[*]}"
"${DOCKER_BUILD_CMD[@]}"

# Check exit code of previous command
if [ $? -ne 0 ]; then
    echo ""
    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
    echo "!! ERROR: Docker build failed, please review logs above !!"
    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
    exit 1
else
    echo ""
    echo "Successfully built Docker image with tag '$TAG'"
    docker images "${TAG}"
fi