Dockerfile

# syntax = docker/dockerfile:1.6.0@sha256:ac85f380a63b13dfcefa89046420e1781752bab202122f8f50032edf31be0021

# Build stage
ARG goversion
FROM --platform=${BUILDPLATFORM} golang:${goversion}-alpine3.20 as base
WORKDIR /spire
RUN apk --no-cache --update add file bash clang lld pkgconfig git make
COPY go.* ./
# https://go.dev/ref/mod#module-cache
RUN --mount=type=cache,target=/go/pkg/mod go mod download
COPY . .

# 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:1.5.0@sha256:0c6a569797744e45955f39d4f7538ac344bfb7ebf0a54006a0a4297b153ccf0f AS xx

FROM --platform=${BUILDPLATFORM} base as builder
ARG TAG
ARG TARGETPLATFORM
ARG TARGETARCH
COPY --link --from=xx / /

RUN xx-go --wrap
RUN set -e ; xx-apk --no-cache --update add build-base musl-dev libseccomp-dev
ENV CGO_ENABLED=1
RUN --mount=type=cache,target=/root/.cache/go-build \
    --mount=type=cache,target=/go/pkg/mod \
    if [ "$TARGETARCH" = "arm64" ]; then CC=aarch64-alpine-linux-musl; elif [ "$TARGETARCH" = "s390x" ]; then CC=s390x-alpine-linux-musl; fi && \
    make build-static git_tag=$TAG git_dirty="" && \
    for f in $(find bin -executable -type f); do xx-verify --static $f; done

FROM --platform=${BUILDPLATFORM} scratch AS spire-base
COPY --link --from=builder --chown=root:root --chmod=755 /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
WORKDIR /opt/spire

# Preparation environment for setting up directories
FROM alpine as prep-spire-server
RUN mkdir -p /spireroot/opt/spire/bin \
    /spireroot/etc/spire/server \
    /spireroot/run/spire/server/private \
    /spireroot/tmp/spire-server/private \
    /spireroot/var/lib/spire/server

FROM alpine as prep-spire-agent
RUN mkdir -p /spireroot/opt/spire/bin \
    /spireroot/etc/spire/agent \
    /spireroot/run/spire/agent/public \
    /spireroot/tmp/spire-agent/public \
    /spireroot/var/lib/spire/agent

# For users that wish to run SPIRE containers with a specific uid and gid, the
# spireuid and spiregid arguments are provided. The default paths that SPIRE
# will try to read from, write to, and create at runtime are given the
# corresponding file ownership/permissions at build time.
# A default non-root user is defined for SPIRE Server and the OIDC Discovery
# Provider. The SPIRE Agent image runs as root by default to facilitate the
# sharing of the agent socket in Kubernetes environments.

# SPIRE Server
FROM spire-base AS spire-server
ARG spireuid=1000
ARG spiregid=1000
USER ${spireuid}:${spiregid}
ENTRYPOINT ["/opt/spire/bin/spire-server", "run"]
COPY --link --from=prep-spire-server --chown=${spireuid}:${spiregid} --chmod=755 /spireroot /
COPY --link --from=builder --chown=${spireuid}:${spiregid} --chmod=755 /spire/bin/static/spire-server /opt/spire/bin/

# SPIRE Agent
FROM spire-base AS spire-agent
ARG spireuid=0
ARG spiregid=0
USER ${spireuid}:${spiregid}
ENTRYPOINT ["/opt/spire/bin/spire-agent", "run"]
COPY --link --from=prep-spire-agent --chown=${spireuid}:${spiregid} --chmod=755 /spireroot /
COPY --link --from=builder --chown=${spireuid}:${spiregid} --chmod=755 /spire/bin/static/spire-agent /opt/spire/bin/

# OIDC Discovery Provider
FROM spire-base AS oidc-discovery-provider
ARG spireuid=1000
ARG spiregid=1000
USER ${spireuid}:${spiregid}
ENTRYPOINT ["/opt/spire/bin/oidc-discovery-provider"]
COPY --link --from=builder --chown=${spireuid}:${spiregid} --chmod=755 /spire/bin/static/oidc-discovery-provider /opt/spire/bin/