Merge pull request #1304 from jjlin/buildx

Use Docker Buildx for multi-arch builds

docker/Dockerfile.buildx

@@ -0,0 +1,33 @@
+# The cross-built images have the build arch (`amd64`) embedded in the image
+# manifest, rather than the target arch. For example:
+#
+#   $ docker inspect bitwardenrs/server:latest-armv7 | jq -r '.[]|.Architecture'
+#   amd64
+#
+# Recent versions of Docker have started printing a warning when the image's
+# claimed arch doesn't match the host arch. For example:
+#
+#   WARNING: The requested image's platform (linux/amd64) does not match the
+#   detected host platform (linux/arm/v7) and no specific platform was requested
+#
+# The image still works fine, but the spurious warning creates confusion.
+#
+# Docker doesn't seem to provide a way to directly set the arch of an image
+# at build time. To resolve the build vs. target arch discrepancy, we use
+# Docker Buildx to build a new set of images with the correct target arch.
+#
+# Docker Buildx uses this Dockerfile to build an image for each requested
+# platform. Since the Dockerfile basically consists of a single `FROM`
+# instruction, we're effectively telling Buildx to build a platform-specific
+# image by simply copying the existing cross-built image and setting the
+# correct target arch as a side effect.
+#
+# References:
+#
+# - https://docs.docker.com/buildx/working-with-buildx/#build-multi-platform-images
+# - https://docs.docker.com/engine/reference/builder/#automatic-platform-args-in-the-global-scope
+# - https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact
+#
+ARG LOCAL_REPO
+ARG DOCKER_TAG
+FROM ${LOCAL_REPO}:${DOCKER_TAG}-${TARGETARCH}${TARGETVARIANT}

docker/Dockerfile.j2

@@ -7,24 +7,24 @@
 {%     set build_stage_base_image = "clux/muslrust:nightly-2020-11-22" %}
 {%     set runtime_stage_base_image = "alpine:3.12" %}
 {%     set package_arch_target = "x86_64-unknown-linux-musl" %}
-{%   elif "arm32v7" in target_file %}
+{%   elif "armv7" in target_file %}
 {%     set build_stage_base_image = "messense/rust-musl-cross:armv7-musleabihf" %}
 {%     set runtime_stage_base_image = "balenalib/armv7hf-alpine:3.12" %}
 {%     set package_arch_target = "armv7-unknown-linux-musleabihf" %}
 {%   endif %}
 {% elif "amd64" in target_file %}
 {%   set runtime_stage_base_image = "debian:buster-slim" %}
-{% elif "arm64v8" in target_file %}
+{% elif "arm64" in target_file %}
 {%   set runtime_stage_base_image = "balenalib/aarch64-debian:buster" %}
 {%   set package_arch_name = "arm64" %}
 {%   set package_arch_target = "aarch64-unknown-linux-gnu" %}
 {%   set package_cross_compiler = "aarch64-linux-gnu" %}
-{% elif "arm32v6" in target_file %}
+{% elif "armv6" in target_file %}
 {%   set runtime_stage_base_image = "balenalib/rpi-debian:buster" %}
 {%   set package_arch_name = "armel" %}
 {%   set package_arch_target = "arm-unknown-linux-gnueabi" %}
 {%   set package_cross_compiler = "arm-linux-gnueabi" %}
-{% elif "arm32v7" in target_file %}
+{% elif "armv7" in target_file %}
 {%   set runtime_stage_base_image = "balenalib/armv7hf-debian:buster" %}
 {%   set package_arch_name = "armhf" %}
 {%   set package_arch_target = "armv7-unknown-linux-gnueabihf" %}
@@ -178,7 +178,7 @@ RUN touch src/main.rs
 # your actual source files being built
 RUN cargo build --features ${DB} --release{{ package_arch_target_param }}
 {% if "alpine" in target_file %}
-{%   if "arm32v7" in target_file %}
+{%   if "armv7" in target_file %}
 RUN musl-strip target/{{ package_arch_target }}/release/bitwarden_rs
 {%   endif %}
 {% endif %}
@@ -225,7 +225,7 @@ RUN apt-get update && apt-get install -y \
     libpq5 \
     && rm -rf /var/lib/apt/lists/*
 {% endif %}
-{% if "alpine" in target_file and "arm32v7" in target_file %}
+{% if "alpine" in target_file and "armv7" in target_file %}
 RUN apk add --no-cache -X http://dl-cdn.alpinelinux.org/alpine/edge/community catatonit
 {% endif %}
 
@@ -256,7 +256,7 @@ HEALTHCHECK --interval=60s --timeout=10s CMD ["/healthcheck.sh"]
 
 # Configures the startup!
 WORKDIR /
-{% if "alpine" in target_file and "arm32v7" in target_file %}
+{% if "alpine" in target_file and "armv7" in target_file %}
 CMD ["catatonit", "/start.sh"]
 {% else %}
 CMD ["/start.sh"]

hooks/README.md

@@ -10,7 +10,7 @@ Docker Hub hooks provide these predefined [environment variables](https://docs.d
 * `DOCKER_TAG`: the Docker repository tag being built.
 * `IMAGE_NAME`: the name and tag of the Docker repository being built. (This variable is a combination of `DOCKER_REPO:DOCKER_TAG`.)
 
-The current multi-arch image build relies on the original bitwarden_rs Dockerfiles, which use cross-compilation for architectures other than `amd64`, and don't yet support all arch/database/OS combinations. However, cross-compilation is much faster than QEMU-based builds (e.g., using `docker buildx`). This situation may need to be revisited at some point.
+The current multi-arch image build relies on the original bitwarden_rs Dockerfiles, which use cross-compilation for architectures other than `amd64`, and don't yet support all arch/distro combinations. However, cross-compilation is much faster than QEMU-based builds (e.g., using `docker buildx`). This situation may need to be revisited at some point.
 
 ## References
 

hooks/arches.sh

@@ -1,19 +1,16 @@
-# The default Debian-based images support these arches for all database connections
-#
-# Other images (Alpine-based) currently
-# support only a subset of these.
+# The default Debian-based images support these arches for all database backends.
 arches=(
     amd64
-    arm32v6
-    arm32v7
-    arm64v8
+    armv6
+    armv7
+    arm64
 )
 
 if [[ "${DOCKER_TAG}" == *alpine ]]; then
-    # The Alpine build currently only works for amd64.
-    os_suffix=.alpine
+    # The Alpine image build currently only works for certain arches.
+    distro_suffix=.alpine
     arches=(
         amd64
-        arm32v7
+        armv7
     )
 fi

hooks/build

@@ -9,6 +9,6 @@ set -ex
 for arch in "${arches[@]}"; do
     docker build \
            -t "${DOCKER_REPO}:${DOCKER_TAG}-${arch}" \
-           -f docker/${arch}/Dockerfile${os_suffix} \
+           -f docker/${arch}/Dockerfile${distro_suffix} \
            .
 done

hooks/pre_build

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -ex
+
+# Print some environment info in case it's useful for troubleshooting.
+id
+pwd
+df -h
+env
+docker info
+docker version
+
+# Install build dependencies.
+deps=(
+    jq
+)
+apt-get update
+apt-get install -y "${deps[@]}"

hooks/push

@@ -1,117 +1,138 @@
 #!/bin/bash
 
-echo ">>> Pushing images..."
-
-export DOCKER_CLI_EXPERIMENTAL=enabled
-
-declare -A annotations=(
-    [amd64]="--os linux --arch amd64"
-    [arm32v6]="--os linux --arch arm --variant v6"
-    [arm32v7]="--os linux --arch arm --variant v7"
-    [arm64v8]="--os linux --arch arm64 --variant v8"
-)
-
 source ./hooks/arches.sh
 
+export DOCKER_CLI_EXPERIMENTAL=enabled
+
+# Join a list of args with a single char.
+# Ref: https://stackoverflow.com/a/17841619
+join() { local IFS="$1"; shift; echo "$*"; }
+
 set -ex
 
-declare -A images
+echo ">>> Starting local Docker registry..."
+
+# Docker Buildx's `docker-container` driver is needed for multi-platform
+# builds, but it can't access existing images on the Docker host (like the
+# cross-compiled ones we just built). Those images first need to be pushed to
+# a registry -- Docker Hub could be used, but since it's not trivial to clean
+# up those intermediate images on Docker Hub, it's easier to just run a local
+# Docker registry, which gets cleaned up automatically once the build job ends.
+#
+# https://docs.docker.com/registry/deploying/
+# https://hub.docker.com/_/registry
+#
+# Use host networking so the buildx container can access the registry via
+# localhost.
+#
+docker run -d --name registry --network host registry:2 # defaults to port 5000
+
+# Docker Hub sets a `DOCKER_REPO` env var with the format `index.docker.io/user/repo`.
+# Strip the registry portion to construct a local repo path for use in `Dockerfile.buildx`.
+LOCAL_REGISTRY="localhost:5000"
+REPO="${DOCKER_REPO#*/}"
+LOCAL_REPO="${LOCAL_REGISTRY}/${REPO}"
+
+echo ">>> Pushing images to local registry..."
+
 for arch in ${arches[@]}; do
-    images[$arch]="${DOCKER_REPO}:${DOCKER_TAG}-${arch}"
+    docker_image="${DOCKER_REPO}:${DOCKER_TAG}-${arch}"
+    local_image="${LOCAL_REPO}:${DOCKER_TAG}-${arch}"
+    docker tag "${docker_image}" "${local_image}"
+    docker push "${local_image}"
 done
 
-# Push the images that were just built; manifest list creation fails if the
-# images (manifests) referenced don't already exist in the Docker registry.
-for image in "${images[@]}"; do
-    docker push "${image}"
-done
+echo ">>> Setting up Docker Buildx..."
 
-manifest_lists=("${DOCKER_REPO}:${DOCKER_TAG}")
+# Same as earlier, use host networking so the buildx container can access the
+# registry via localhost.
+#
+# Ref: https://github.com/docker/buildx/issues/94#issuecomment-534367714
+#
+docker buildx create --name builder --use --driver-opt network=host
 
-# If the Docker tag starts with a version number, assume the latest release is
-# being pushed. Add an extra manifest (`latest` or `alpine`, as appropriate)
+echo ">>> Running Docker Buildx..."
+
+tags=("${DOCKER_REPO}:${DOCKER_TAG}")
+
+# If the Docker tag starts with a version number, assume the latest release
+# is being pushed. Add an extra tag (`latest` or `alpine`, as appropriate)
 # to make it easier for users to track the latest release.
 if [[ "${DOCKER_TAG}" =~ ^[0-9]+\.[0-9]+\.[0-9]+ ]]; then
     if [[ "${DOCKER_TAG}" == *alpine ]]; then
-        manifest_lists+=(${DOCKER_REPO}:alpine)
+        tags+=(${DOCKER_REPO}:alpine)
     else
-        manifest_lists+=(${DOCKER_REPO}:latest)
-
-        # Add an extra `latest-arm32v6` tag; Docker can't seem to properly
-        # auto-select that image on Armv6 platforms like Raspberry Pi 1 and Zero
-        # (https://github.com/moby/moby/issues/41017).
-        #
-        # Add this tag only for the SQLite image, as the MySQL and PostgreSQL
-        # builds don't currently work on non-amd64 arches.
-        #
-        # TODO: Also add an `alpine-arm32v6` tag if multi-arch support for
-        # Alpine-based bitwarden_rs images is implemented before this Docker
-        # issue is fixed.
-        if [[ ${DOCKER_REPO} == *server ]]; then
-            docker tag "${DOCKER_REPO}:${DOCKER_TAG}-arm32v6" "${DOCKER_REPO}:latest-arm32v6"
-            docker push "${DOCKER_REPO}:latest-arm32v6"
-        fi
+        tags+=(${DOCKER_REPO}:latest)
     fi
 fi
 
-for manifest_list in "${manifest_lists[@]}"; do
-    # Create the (multi-arch) manifest list of arch-specific images.
-    docker manifest create ${manifest_list} ${images[@]}
-
-    # Make sure each image manifest is annotated with the correct arch info.
-    # Docker does not auto-detect the arch of each cross-compiled image, so
-    # everything would appear as `linux/amd64` otherwise.
-    for arch in "${arches[@]}"; do
-        docker manifest annotate ${annotations[$arch]} ${manifest_list} ${images[$arch]}
+tag_args=()
+for tag in "${tags[@]}"; do
+    tag_args+=(--tag "${tag}")
 done
 
-    # Push the manifest list.
-    docker manifest push --purge ${manifest_list}
-done
-
-# Avoid logging credentials and tokens.
-set +ex
-
-# Delete the arch-specific tags, if credentials for doing so are available.
-# Note that `DOCKER_PASSWORD` must be the actual user password. Passing a JWT
-# obtained using a personal access token results in a 403 error with
-# {"detail": "access to the resource is forbidden with personal access token"}
-if [[ -z "${DOCKER_USERNAME}" || -z "${DOCKER_PASSWORD}" ]]; then
-    exit 0
-fi
-
-# Given a JSON input on stdin, extract the string value associated with the
-# specified key. This avoids an extra dependency on a tool like `jq`.
-extract() {
-    local key="$1"
-    # Extract "<key>":"<val>" (assumes key/val won't contain double quotes).
-    # The colon may have whitespace on either side.
-    grep -o "\"${key}\"[[:space:]]*:[[:space:]]*\"[^\"]\+\"" |
-    # Extract just <val> by deleting the last '"', and then greedily deleting
-    # everything up to '"'.
-    sed -e 's/"$//' -e 's/.*"//'
-}
-
-echo ">>> Getting API token..."
-jwt=$(curl -sS -X POST \
-           -H "Content-Type: application/json" \
-           -d "{\"username\":\"${DOCKER_USERNAME}\",\"password\": \"${DOCKER_PASSWORD}\"}" \
-           "https://hub.docker.com/v2/users/login" |
-      extract 'token')
-
-# Strip the registry portion from `index.docker.io/user/repo`.
-repo="${DOCKER_REPO#*/}"
-
+# Docker Buildx takes a list of target platforms (OS/arch/variant), so map
+# the arch list to a platform list (assuming the OS is always `linux`).
+declare -A arch_to_platform=(
+    [amd64]="linux/amd64"
+    [armv6]="linux/arm/v6"
+    [armv7]="linux/arm/v7"
+    [arm64]="linux/arm64"
+)
+platforms=()
 for arch in ${arches[@]}; do
-    # Don't delete the `arm32v6` tag; Docker can't seem to properly
-    # auto-select that image on Armv6 platforms like Raspberry Pi 1 and Zero
-    # (https://github.com/moby/moby/issues/41017).
-    if [[ ${arch} == 'arm32v6' ]]; then
-        continue
-    fi
-    tag="${DOCKER_TAG}-${arch}"
-    echo ">>> Deleting '${repo}:${tag}'..."
-    curl -sS -X DELETE \
-         -H "Authorization: Bearer ${jwt}" \
-         "https://hub.docker.com/v2/repositories/${repo}/tags/${tag}/"
+    platforms+=("${arch_to_platform[$arch]}")
 done
+platforms="$(join "," "${platforms[@]}")"
+
+# Run the build, pushing the resulting images and multi-arch manifest list to
+# Docker Hub. The Dockerfile is read from stdin to avoid sending any build
+# context, which isn't needed here since the actual cross-compiled images
+# have already been built.
+docker buildx build \
+       --network host \
+       --build-arg LOCAL_REPO="${LOCAL_REPO}" \
+       --build-arg DOCKER_TAG="${DOCKER_TAG}" \
+       --platform "${platforms}" \
+       "${tag_args[@]}" \
+       --push \
+       - < ./docker/Dockerfile.buildx
+
+# Add an extra arch-specific tag for `arm32v6`; Docker can't seem to properly
+# auto-select that image on ARMv6 platforms like Raspberry Pi 1 and Zero
+# (https://github.com/moby/moby/issues/41017).
+#
+# Note that we use `arm32v6` instead of `armv6` to be consistent with the
+# existing bitwarden_rs tags, which adhere to the naming conventions of the
+# Docker per-architecture repos (e.g., https://hub.docker.com/u/arm32v6).
+# Unfortunately, these per-arch repo names aren't always consistent with the
+# corresponding platform (OS/arch/variant) IDs, particularly in the case of
+# 32-bit ARM arches (e.g., `linux/arm/v6` is used, not `linux/arm32/v6`).
+#
+# TODO: It looks like this issue should be fixed starting in Docker 20.10.0,
+# so this step can be removed once fixed versions are in wider distribution.
+#
+# Tags:
+#
+#   testing        => testing-arm32v6
+#   testing-alpine => <ignored>
+#   x.y.z          => x.y.z-arm32v6, latest-arm32v6
+#   x.y.z-alpine   => <ignored>
+#
+if [[ "${DOCKER_TAG}" != *alpine ]]; then
+    image="${DOCKER_REPO}":"${DOCKER_TAG}"
+
+    # Fetch the multi-arch manifest list and find the digest of the armv6 image.
+    filter='.manifests|.[]|select(.platform.architecture=="arm" and .platform.variant=="v6")|.digest'
+    digest="$(docker manifest inspect "${image}" | jq -r "${filter}")"
+
+    # Pull the armv6 image by digest, retag it, and repush it.
+    docker pull "${DOCKER_REPO}"@"${digest}"
+    docker tag "${DOCKER_REPO}"@"${digest}" "${image}"-arm32v6
+    docker push "${image}"-arm32v6
+
+    if [[ "${DOCKER_TAG}" =~ ^[0-9]+\.[0-9]+\.[0-9]+ ]]; then
+        docker tag "${image}"-arm32v6 "${DOCKER_REPO}:latest"-arm32v6
+        docker push "${DOCKER_REPO}:latest"-arm32v6
+    fi
+fi