Multi arch docker build

.github/workflows/scripts/load-oci-archives.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+# shellcheck shell=bash
+##
+## USAGE: __PROG__
+##
+## "__PROG__" loads oci tarballs created with xbuild into docker.
+##
+## Usage example(s):
+##   ./__PROG__
+##   PLATFORM=linux/arm64 ./__PROG__
+##
+## Commands
+## - ./__PROG__   loads the oci tarball into Docker.
+
+function usage {
+  grep '^##' "$0" | sed -e 's/^##//' -e "s/__PROG__/$me/" >&2
+}
+
+function normalize_path {
+    # Remove all /./ sequences.
+    local path=${1//\/.\//\/}
+    local npath
+    # Remove first dir/.. sequence.
+    npath="${path//[^\/][^\/]*\/\.\.\//}"
+    # Remove remaining dir/.. sequence.
+    while [[ $npath != "$path" ]] ; do
+        path=$npath
+        npath="${path//[^\/][^\/]*\/\.\.\//}"
+    done
+    echo "$path"
+}
+
+me=$(basename "$0")
+BASEDIR=$(dirname "$0")
+ROOTDIR="$(normalize_path "$BASEDIR/../../../")"
+
+command -v regctl >/dev/null 2>&1 || { usage; echo -e "\n * The regctl cli is required to run this script." >&2 ; exit 1; }
+command -v docker >/dev/null 2>&1 || { usage; echo -e "\n * The docker cli is required to run this script." >&2 ; exit 1; }
+
+# Takes the current platform architecture or plaftorm as defined externally in a platform variable.
+# e.g.:
+# linux/amd64
+# linux/arm64
+PLATFORM="${PLATFORM:-local}"
+OCI_IMAGES=(
+    spiffe-helper
+)
+
+org_name=$(echo "$GITHUB_REPOSITORY" | tr '/' "\n" | head -1 | tr -d "\n")
+org_name="${org_name:-spiffe}" # default to spiffe in case ran on local
+registry=ghcr.io/${org_name}
+
+echo "Importing ${OCI_IMAGES[*]} into docker".
+for img in "${OCI_IMAGES[@]}"; do
+    oci_dir="ocidir://${ROOTDIR}oci/${img}"
+    platform_tar="${img}-${PLATFORM}-image.tar"
+    image_to_load="${registry}/${img}:devel"
+
+    # regclient works with directories rather than tars, so import the OCI tar to a directory
+    regctl image import "$oci_dir" "${img}-image.tar"
+    dig="$(regctl image digest --platform "$PLATFORM" "$oci_dir")"
+    # export the single platform image using the digest
+    regctl image export "$oci_dir@${dig}" "${platform_tar}"
+
+    docker load < "${platform_tar}"
+    docker image tag "localhost/oci/${img}:latest" "${image_to_load}"
+    docker image rm "localhost/oci/${img}:latest"
+done

.gitignore

@@ -7,3 +7,7 @@ rpm/*.rpm
 *.swp
 *.swo
 bootstrap.crt
+
+# oci image builds
+oci/
+*-image.tar

Dockerfile

@@ -1,10 +1,40 @@
-FROM golang
+# Build the spiffe-helper binary
+ARG go_version
+FROM --platform=$BUILDPLATFORM golang:${go_version}-alpine as base
+WORKDIR /workspace
 
-WORKDIR /build
-COPY . /build
-RUN CGO_ENABLED=0 go build -o spiffe-helper ./cmd/spiffe-helper
+# Cache deps before building and copying source so that we don't need to re-download as much
+# and so that source changes don't invalidate our downloaded layer
+COPY go.* ./
+RUN --mount=type=cache,target=/go/pkg/mod go mod download
+
+# Copy the go source
+COPY cmd/spiffe-helper/main.go cmd/spiffe-helper/main.go
+COPY pkg/ pkg/
+
+# xx is a helper for cross-compilation
+# when bumping to a new version analyze the new version for security issues
+# then use crane to lookup the digest of that version so we are immutable
+# crane digest tonistiigi/xx:1.3.0
+FROM --platform=${BUILDPLATFORM} tonistiigi/xx@sha256:904fe94f236d36d65aeb5a2462f88f2c537b8360475f6342e7599194f291fb7e AS xx
+
+FROM --platform=${BUILDPLATFORM} base as builder
+ARG TARGETPLATFORM
+ARG TARGETARCH
+
+ENV CGO_ENABLED=0
+COPY --link --from=xx / /
+RUN xx-go --wrap
+RUN --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg/mod \
+    go build -o bin/spiffe-helper cmd/spiffe-helper/main.go
+
+# Use distroless as minimal base image to package the manager binary
+# Refer to https://github.com/GoogleContainerTools/distroless for more details
+#FROM gcr.io/distroless/static:nonroot
+FROM gcr.io/distroless/static AS spiffe-helper
+WORKDIR /
+COPY --link --from=builder /workspace/bin/spiffe-helper /spiffe-helper
 
-FROM scratch
-COPY --from=0 /build/spiffe-helper /spiffe-helper
 ENTRYPOINT ["/spiffe-helper"]
-CMD ["-config", "/etc/spiffe-helper.conf"]
+CMD []

Makefile

@@ -1,5 +1,6 @@
 export GO111MODULE=on
 DIR := ${CURDIR}
+PLATFORMS ?= linux/amd64,linux/arm64
 
 E:=@
 ifeq ($(V),1)
@@ -41,6 +42,15 @@ help:
 	@echo "For verbose output set V=1"
 	@echo "  for example: $(cyan)make V=1 build$(reset)"
 
+# Used to force some rules to run every time
+.PHONY: FORCE
+FORCE: ;
+
+# CONTAINER_TOOL defines the container tool to be used for building images.
+# Be aware that the target commands are only tested with Docker which is
+# scaffolded by default. However, you might want to replace it to use other
+# tools. (i.e. podman)
+CONTAINER_TOOL ?= docker
 
 ############################################################################
 # OS/ARCH detection
@@ -167,11 +177,27 @@ lint-code: $(golangci_lint_bin) | go-check
 # Build targets
 ############################################################################
 
-.PHONY: build test clean distclean artifact tarball rpm
+.PHONY: build test clean distclean artifact tarball rpm docker-build container-builder load-images
 
 build: | go-check
 	go build -o spiffe-helper${exe} ./cmd/spiffe-helper
 
+docker-build: $(addsuffix -image.tar, spiffe-helper) ## Build docker image with spiffe-helper.
+
+container-builder: ## Create a buildx node to create crossplatform images.
+	$(CONTAINER_TOOL) buildx create --platform $(PLATFORMS) --name container-builder --node container-builder0 --use
+
+spiffe-helper-image.tar: Dockerfile FORCE | container-builder
+	$(CONTAINER_TOOL) buildx build \
+		--platform $(PLATFORMS) \
+		--build-arg go_version=$(go_version) \
+		--target spiffe-helper \
+		-o type=oci,dest=$@ \
+	    .
+
+load-images: $(addsuffix -image.tar,$(BINARIES)) ## Load the image for your current PLATFORM into docker from the cross-platform oci tar.
+	./.github/workflows/scripts/load-oci-archives.sh
+
 artifact: tarball rpm
 
 tarball: build