docker-build.sh

# Date: Mary 17, 2020
# Author: Ishaat Chowdhury
# Contents: bash script to build docker images for project
#
# Attributions:
# - https://pythonspeed.com/articles/faster-multi-stage-builds/ 
# - https://www.devdungeon.com/content/taking-command-line-arguments-bash

# Source common definitions
source common.sh

# Create and set buildkit builder instance
if ! docker buildx use mybuilder; then
    docker buildx create --name mybuilder
    docker buildx use mybuilder
    docker buildx inspect --bootstrap
fi

# Pull the latest version of the image, in order to populate the build cache
# Pipe || true to prevent failures when image doesn't exist in registry
docker pull $PRE_BUILD_STAGE_IMAGE || true
docker pull $BUILD_STAGE_IMAGE || true
docker pull $RPI_IMAGE || true

# Build the pre build stage image:
docker buildx build --platform linux/arm/v7 --load --target pre-build-image \
    --build-arg BUILDKIT_INLINE_CACHE=1 \
    --cache-from=$PRE_BUILD_STAGE_IMAGE \
    --tag $PRE_BUILD_STAGE_IMAGE .

# Build the build stage image:
docker buildx build --platform linux/arm/v7 --load --target build-image \
    --build-arg BUILDKIT_INLINE_CACHE=1 \
    --cache-from=$PRE_BUILD_STAGE_IMAGE \
    --cache-from=$BUILD_STAGE_IMAGE \
    --tag $BUILD_STAGE_IMAGE .

# Build the runtime stage image:
docker buildx build --platform linux/arm/v7 --load --target runtime-image \
    --build-arg BUILDKIT_INLINE_CACHE=1 \
    --cache-from=$PRE_BUILD_STAGE_IMAGE \
    --cache-from=$BUILD_STAGE_IMAGE \
    --cache-from=$RPI_IMAGE \
    --tag $RPI_IMAGE .