dex/Dockerfile

ARG BASE_IMAGE=alpine

FROM --platform=$BUILDPLATFORM tonistiigi/xx:1.9.0@sha256:c64defb9ed5a91eacb37f96ccc3d4cd72521c4bd18d5442905b95e2226b0e707 AS xx

FROM --platform=$BUILDPLATFORM golang:1.26.2-alpine3.22@sha256:c259ff7ffa06f1fd161a6abfa026573cf00f64cfd959c6d2a9d43e3ff63e8729 AS builder

COPY --from=xx / /

RUN apk add --update alpine-sdk ca-certificates openssl clang lld

ARG TARGETPLATFORM

RUN xx-apk --update add musl-dev gcc

# lld has issues building static binaries for ppc so prefer ld for it
RUN [ "$(xx-info arch)" != "ppc64le" ] || XX_CC_PREFER_LINKER=ld xx-clang --setup-target-triple

RUN xx-go --wrap

WORKDIR /usr/local/src/dex

ARG GOPROXY

ENV CGO_ENABLED=1

COPY go.mod go.sum ./
COPY api/v2/go.mod api/v2/go.sum ./api/v2/
RUN go mod download

COPY . .

# Propagate Dex version from build args to the build environment
ARG VERSION
RUN make release-binary

RUN xx-verify /go/bin/dex && xx-verify /go/bin/docker-entrypoint

FROM alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 AS stager

RUN mkdir -p /var/dex
RUN mkdir -p /etc/dex
COPY config.docker.yaml /etc/dex/

FROM alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 AS gomplate

ARG TARGETOS
ARG TARGETARCH
ARG TARGETVARIANT

ENV GOMPLATE_VERSION=v5.0.0

RUN wget -O /usr/local/bin/gomplate \
    "https://github.com/hairyhenderson/gomplate/releases/download/${GOMPLATE_VERSION}/gomplate_${TARGETOS:-linux}-${TARGETARCH:-amd64}${TARGETVARIANT}" \
    && chmod +x /usr/local/bin/gomplate

# For Dependabot to detect base image versions
FROM alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 AS alpine

FROM alpine AS user-setup
RUN addgroup -g 1001 -S dex && adduser -u 1001 -S -G dex -D -H -s /sbin/nologin dex

FROM gcr.io/distroless/static-debian13:nonroot@sha256:e3f945647ffb95b5839c07038d64f9811adf17308b9121d8a2b87b6a22a80a39 AS distroless

FROM $BASE_IMAGE

# Dex connectors, such as GitHub and Google logins require root certificates.
# Proper installations should manage those certificates, but it's a bad user
# experience when this doesn't work out of the box.
#
# See https://go.dev/src/crypto/x509/root_linux.go for Go root CA bundle locations.
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt

# Ensure the dex user/group exist before setting ownership or switching to them.
COPY --from=user-setup /etc/passwd /etc/passwd
COPY --from=user-setup /etc/group /etc/group

COPY --from=stager --chown=1001:1001 /var/dex /var/dex
COPY --from=stager --chown=1001:1001 /etc/dex /etc/dex

# Copy module files for CVE scanning / dependency analysis.
COPY --from=builder /usr/local/src/dex/go.mod /usr/local/src/dex/go.sum /usr/local/src/dex/
COPY --from=builder /usr/local/src/dex/api/v2/go.mod /usr/local/src/dex/api/v2/go.sum /usr/local/src/dex/api/v2/

COPY --from=builder /go/bin/dex /usr/local/bin/dex
COPY --from=builder /go/bin/docker-entrypoint /usr/local/bin/docker-entrypoint
COPY --from=builder /usr/local/src/dex/web /srv/dex/web

COPY --from=gomplate /usr/local/bin/gomplate /usr/local/bin/gomplate

USER dex:dex

ENTRYPOINT ["/usr/local/bin/docker-entrypoint"]
CMD ["dex", "serve", "/etc/dex/config.docker.yaml"]