Dockerfile

FROM golang:1.17 as builder
WORKDIR /workspace

# Run this with docker build --build_arg $(go env GOPROXY) to override the goproxy
ARG goproxy=https://proxy.golang.org
ENV GOPROXY=$goproxy

# 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 sources
COPY ./ ./

RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
    go build -a -ldflags '-extldflags "-static"' \
    -o tweeter .

# Copy the action into a thin image
FROM gcr.io/distroless/static:latest
WORKDIR /
COPY --from=builder /workspace/tweeter .
ENTRYPOINT ["/tweeter"]