Dockerfile

# Build the  binary
FROM --platform=$BUILDPLATFORM golang:1.19 as builder
ARG TARGETOS
ARG TARGETARCH

WORKDIR /workspace
# Copy the Go Modules manifests
COPY go.mod go.mod
COPY go.sum go.sum
# 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
RUN go mod download

# Copy the go source
COPY dns.go dns.go
COPY resolve.go resolve.go
COPY internal/ internal/

# Build
RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} GO111MODULE=on go build -a -o dns-zone-aware-resolver

# 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
WORKDIR /
COPY --from=builder /workspace/dns-zone-aware-resolver .
USER nonroot:nonroot

ENTRYPOINT ["/dns-zone-aware-resolver"]