Dockerfile

FROM golang:1.23.1-alpine3.20 AS builder
ARG TARGETOS
ARG TARGETARCH
ARG LDFLAGS

WORKDIR /app

# Copy the Go Modules manifests and cache the dependencies
COPY go.mod go.mod
COPY go.sum go.sum
RUN go mod download

# Copy the go source
COPY . /app

# Build
# the GOARCH has not a default value to allow the binary be built according to the host where the command
# was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
# the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
# by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -ldflags="${LDFLAGS}" -a -o dex-http-server cmd/main.go

FROM gcr.io/distroless/static:nonroot
WORKDIR /
COPY --from=builder /app/dex-http-server .
USER 65532:65532

ENTRYPOINT ["/dex-http-server"]