Dockerfile

ARG GO_VERSION=1.11

# First stage: build the executable.
FROM golang:${GO_VERSION}-alpine AS builder

RUN mkdir /user && \
    echo 'nobody:x:65534:65534:nobody:/:' > /user/passwd && \
    echo 'nobody:x:65534:' > /user/group

RUN apk add --no-cache ca-certificates git

ENV CGO_ENABLED=0

# Set the working directory outside $GOPATH to enable the support for modules.
WORKDIR /src

# Import the code from the context.
COPY ./ ./

# Build the executable to `/app`. Mark the build as statically linked.
RUN go build \
    -installsuffix 'static' \
    -o /konfig-syncer .

# Final stage: the running container.
FROM alpine:3.9 AS final

# Import the user and group files from the first stage.
COPY --from=builder /user/group /user/passwd /etc/

# Import the Certificate-Authority certificates for enabling HTTPS.
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/

# Import the compiled executable from the second stage.
COPY --from=builder /konfig-syncer /konfig-syncer

# Run the compiled binary.
ENTRYPOINT ["/konfig-syncer"]