Dockerfile

# Copyright 2019 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Build the manager binary
FROM --platform=${BUILDPLATFORM} docker.io/library/golang:1.20.7 as build
ARG TARGETOS TARGETARCH
ARG package

WORKDIR /workspace

# Run this with docker build --build-arg goproxy=$(go env GOPROXY) to override the goproxy
ARG goproxy=https://proxy.golang.org
# Run this with docker build --build-arg package=./controlplane/kubeadm or --build-arg package=./bootstrap/kubeadm
ENV GOPROXY=$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 ./ ./

# Cache the go build into the Go’s compiler cache folder so we take benefits of compiler caching across docker build calls
RUN --mount=type=cache,target=/root/.cache/go-build \
    --mount=type=cache,target=/go/pkg/mod \
    go build ./bootstrap/main.go

RUN --mount=type=cache,target=/root/.cache \
    --mount=type=cache,target=/go/pkg \
    GOOS=${TARGETOS} GOARCH=${TARGETARCH} CGO_ENABLED=0 \
    go build -ldflags "${LDFLAGS} -extldflags '-static'" \
    -o manager ${package}

FROM --platform=${BUILDPLATFORM} gcr.io/distroless/static:nonroot
WORKDIR /
COPY --from=build /workspace/manager .
# Use uid of nonroot user (65532) because kubernetes expects numeric user when applying pod security policies
USER 65532
ENTRYPOINT ["/manager"]