Dockerfile

# Build the manager binary
FROM golang:1.19.6 as builder
WORKDIR /workspace

# Run this with docker build --build_arg goproxy=$(go env GOPROXY) to override the goproxy
ARG goproxy=https://proxy.golang.org
ENV GOPROXY=$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 --mount=type=cache,target=/go/pkg/mod \
    go mod download

# Copy the sources
COPY ./ ./

# Build
ARG package=.
ARG ARCH
ARG ldflags

# Do not force rebuild of up-to-date packages (do not use -a) and use the compiler cache folder
RUN --mount=type=cache,target=/root/.cache/go-build \
    --mount=type=cache,target=/go/pkg/mod \
    CGO_ENABLED=0 GOOS=linux GOARCH=${ARCH} \
    go build -ldflags "${ldflags} -extldflags '-static'" \
    -o manager ${package}

# Production image
FROM alpine:3.11
WORKDIR /
COPY --from=builder /workspace/manager .
# add new user
ARG USER=nonroot
ENV HOME /home/$USER
RUN adduser -D $USER \
        && mkdir -p /etc/sudoers.d \
        && echo "$USER ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/$USER \
        && chmod 0440 /etc/sudoers.d/$USER
USER $USER:$USER

ENTRYPOINT ["/manager"]