[rel-v3.4.13] Build Multi-Arch Images 📦 (#19)

* Add support for ARM64

* Let pipeline build multi-arch images

* Bump etcd-custom-image version

.ci/pipeline_definitions

@@ -13,7 +13,10 @@ etcd-custom-image:
       traits:
         draft_release: ~
         publish:
-          oci-builder: 'docker'
+          oci-builder: docker-buildx
+          platforms:
+          - linux/amd64
+          - linux/arm64
           dockerimages:
             etcd:
               registry: 'gcr-readwrite'

Dockerfile

@@ -1,7 +1,11 @@
 # SPDX-FileCopyrightText: 2020 SAP SE or an SAP affiliate company and Gardener contributors
 # SPDX-License-Identifier: Apache-2.0
 
-FROM gcr.io/etcd-development/etcd:v3.4.13 as source
+FROM gcr.io/etcd-development/etcd:v3.4.13 as source-amd64
+FROM gcr.io/etcd-development/etcd:v3.4.13-arm64 as source-arm64
+
+FROM source-$TARGETARCH as source
+
 FROM alpine:3.15.4
 
 WORKDIR /

Dockerfile.template

@@ -1,7 +1,11 @@
 # SPDX-FileCopyrightText: 2020 SAP SE or an SAP affiliate company and Gardener contributors
 # SPDX-License-Identifier: Apache-2.0
 
-FROM gcr.io/etcd-development/etcd:ETCD_VERSION as source
+FROM gcr.io/etcd-development/etcd:ETCD_VERSION as source-amd64
+FROM gcr.io/etcd-development/etcd:ETCD_VERSION as source-arm64
+
+FROM source-$TARGETARCH as source
+
 FROM alpine:3.15.4
 
 WORKDIR /

VERSION

@@ -1 +1 @@
-v3.4.13-bootstrap-5
+v3.4.13-bootstrap-6

etcd_bootstrap_script.sh

@@ -22,6 +22,12 @@ trap_and_propagate() {
 }
 
 start_managed_etcd(){
+      arch=$(uname -m)
+      if [ $arch = "aarch64" ] || [ $arch = "arm64" ]; then
+          # Running etcd on ARM has experimental support for version 3.4.x
+          # https://etcd.io/docs/v3.4/op-guide/supported-platform/
+          export ETCD_UNSUPPORTED_ARCH=arm64
+      fi
       rm -rf $VALIDATION_MARKER
       CONFIG_FILE=/etc/etcd.conf.yaml
       curl "$BACKUP_ENDPOINT/config" -o $CONFIG_FILE