Dockerfile

############################
# STEP 1 build executable binary
############################
FROM golang:alpine as builder

# Install git + SSL ca certificates.
# Git is required for fetching the dependencies.
# Ca-certificates is required to call HTTPS endpoints.
RUN apk update && apk add --no-cache git ca-certificates && update-ca-certificates

# Create appuser
ENV USER=appuser
ENV UID=1000

# See https://stackoverflow.com/a/55757473/12429735RUN
RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "/nonexistent" \
    --shell "/sbin/nologin" \
    --no-create-home \
    --uid "${UID}" \
    "${USER}"
WORKDIR /src
COPY . .

# Fetch dependencies.# Using go mod with go 1.11
RUN go mod download
RUN go mod verify

# Build the binary
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64\
 go build\
  -ldflags='-w -s -extldflags "-static"'\
  -o /go/bin/helloneighbour cmd/helloneighbour.go

############################
# STEP 2 build a small image
############################
FROM scratch

# Import from builder.
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
COPY --from=builder /etc/passwd /etc/passwd
COPY --from=builder /etc/group /etc/group

# Copy our static executable
COPY --from=builder /go/bin/helloneighbour /go/bin/helloneighbour

# Use an unprivileged user.
USER appuser:appuser

# Run the hello binary.
ENTRYPOINT ["/go/bin/helloneighbour"]