ContainerImage.Pinniped/Dockerfile
Matt Moyer 8a41419b94
Optimize image build using .dockerignore and BuildKit features.
This optimizes our image in a few different ways:

- It adds a bunch of files and directories to the `.dockerignore` file.
  This lets us have a single `COPY . .` but still be very aggressive about pruning what files end up in the build context.

- It adds build-time cache mounts to the `go build` commands using BuildKit's `--mount=type=cache` flag.
  This requires BuildKit-capable Docker, but means that our Go builds can all be incremental builds.
  This replaces the previous flow we had where we needed to split out `go mod download`.

- Instead of letting the full `apt-get install ca-certificates` layer end up in our final image, we copy just the single file we need.

Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-01-27 10:42:56 -06:00

48 lines
1.4 KiB
Docker

# syntax = docker/dockerfile:1.0-experimental
# Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
FROM golang:1.15.7 as build-env
WORKDIR /work
COPY . .
ARG GOPROXY
# Build the executable binary (CGO_ENABLED=0 means static linking)
# Pass in GOCACHE (build cache) and GOMODCACHE (module cache) so they
# can be re-used between image builds.
RUN \
--mount=type=cache,target=/cache/gocache \
--mount=type=cache,target=/cache/gomodcache \
mkdir out && \
GOCACHE=/cache/gocache \
GOMODCACHE=/cache/gomodcache \
CGO_ENABLED=0 \
GOOS=linux \
GOARCH=amd64 \
go build -v -ldflags "$(hack/get-ldflags.sh)" -o out \
./cmd/pinniped-concierge/... \
./cmd/pinniped-supervisor/... \
./cmd/local-user-authenticator/...
# Use a Debian slim image to grab a reasonable default CA bundle.
FROM debian:10.7-slim AS get-ca-bundle-env
RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates && rm -rf /var/lib/apt/lists/* /var/cache/debconf/*
# Use a runtime image based on Debian slim.
FROM debian:10.7-slim
COPY --from=get-ca-bundle-env /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
# Copy the binaries from the build-env stage.
COPY --from=build-env /work/out/ /usr/local/bin/
# Document the ports
EXPOSE 8080 8443
# Run as non-root for security posture
USER 1001:1001
# Set the entrypoint
ENTRYPOINT ["/usr/local/bin/pinniped-concierge"]