use distroless base image

Signed-off-by: Matthias Bertschy <matthias.bertschy@gmail.com>

build/Dockerfile

@@ -1,11 +1,20 @@
-FROM golang:1.19 
+FROM --platform=$BUILDPLATFORM golang:1.20-bullseye as builder
 ARG BUILD_VERSION
-WORKDIR /app/
-COPY . ./
-ENV CGO_ENABLED=0
-RUN go get ./...
-RUN go build -o kube-host-sensor --ldflags "-w -s -X main.BuildVersion=$BUILD_VERSION"
-
-FROM alpine
-COPY --from=0 /app/kube-host-sensor /.
-ENTRYPOINT [ "./kube-host-sensor" ]
+ENV GO111MODULE=on CGO_ENABLED=0
+WORKDIR /work
+ARG TARGETOS TARGETARCH
+
+RUN --mount=target=. \
+    --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg \
+    GOOS=$TARGETOS GOARCH=$TARGETARCH go build -o /out/kube-host-sensor --ldflags "-w -s -X main.BuildVersion=$BUILD_VERSION" .
+
+FROM gcr.io/distroless/static-debian11:latest
+
+COPY --from=builder /out/kube-host-sensor /usr/bin/kube-host-sensor
+
+ARG image_version
+ENV RELEASE=$image_version
+
+WORKDIR /root
+ENTRYPOINT ["kube-host-sensor"]