build: Add new multi-platform operator image

This intial version includes all operator falavours, since
parametrisation needs some more work to be fully integrated,
and it's better to avoid duplication of Dockerfiles.

Signed-off-by: Ilya Dmitrichenko <errordeveloper@gmail.com>

images/operator/Dockerfile

@@ -0,0 +1,33 @@
+# syntax=docker/dockerfile:1.1-experimental
+
+# Copyright 2020 Authors of Cilium
+# SPDX-License-Identifier: Apache-2.0
+
+ARG CILIUM_BUILDER_IMAGE=docker.io/cilium/cilium-builder-dev:b030f1ed16c21608d78564124a870a18ca485444
+ARG CA_CERTIFICATES_IMAGE=docker.io/cilium/ca-certificates:69a9f5d66ff96bf97e8b9dc107e92aa9ddbdc9a8
+
+FROM --platform=linux/amd64 ${CILIUM_BUILDER_IMAGE} as builder
+
+ARG NOSTRIP
+ARG LOCKDEBUG
+
+RUN --mount=type=bind,readwrite,target=/go/src/github.com/cilium/cilium --mount=target=/root/.cache,type=cache --mount=target=/go/pkg/mod,type=cache \
+  make -C operator \
+    NOSTRIP=$NOSTRIP LOCKDEBUG=$LOCKDEBUG PKG_BUILD=1 \
+  && mkdir -p /out/linux/amd64/usr/bin && mv operator/cilium-operator* /out/linux/amd64/usr/bin
+
+RUN --mount=type=bind,readwrite,target=/go/src/github.com/cilium/cilium --mount=target=/root/.cache,type=cache --mount=target=/go/pkg/mod,type=cache \
+  env GOARCH=arm64 \
+    make -C operator \
+      NOSTRIP=$NOSTRIP LOCKDEBUG=$LOCKDEBUG PKG_BUILD=1 \
+  && mkdir -p /out/linux/arm64/usr/bin && mv operator/cilium-operator* /out/linux/arm64/usr/bin
+
+
+FROM ${CA_CERTIFICATES_IMAGE}
+ARG TARGETPLATFORM
+LABEL maintainer="maintainer@cilium.io"
+
+COPY --from=builder /out/${TARGETPLATFORM} /
+
+WORKDIR /
+CMD ["/usr/bin/cilium-operator-generic"]

images/operator/Dockerfile.dockerignore

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+# Copyright 2020 Authors of Cilium
+# SPDX-License-Identifier: Apache-2.0
+
+# since this is image is built with root context, most of the files
+# need to be excluded for faster builds and to avoid spoiling build
+# cache due to unchecked files (like configs or random binaries)
+*
+
+# must-have toplevel files
+!/Makefile*
+!/go.sum
+!/go.mod
+!/VERSION
+# TODO: this is currently a make dependency, but should be removed
+# in the future
+!/Dockerfile
+
+# directories
+!/api
+!/pkg
+!/vendor
+!/operator