Standardize image artifact name

Standardize the arch in image artifact name to amd64 (instead of x86_64), and arm64 (instead of aarch64)

.buildkite/scripts/dra/build_docker.sh

@@ -29,6 +29,9 @@ rake artifact:dockerfiles || error "artifact:dockerfiles build failed."
 STACK_VERSION="$(./$(dirname "$0")/../common/qualified-version.sh)"
 info "Build complete, setting STACK_VERSION to $STACK_VERSION."
 
+# standardize $ARCH for image name
+normalize_arch
+
 info "Saving tar.gz for docker images"
 save_docker_tarballs "${ARCH}" "${STACK_VERSION}"
 
@@ -44,7 +47,7 @@ done
 
 # Upload 'docker-build-context.tar.gz' files only when build x86_64, otherwise they will be
 # overwritten when building aarch64 (or viceversa).
-if [ "$ARCH" != "aarch64" ]; then
+if [ "$ARCH" != "arm64" ]; then
     for image in logstash logstash-oss logstash-wolfi logstash-ironbank; do
         buildkite-agent artifact upload "build/${image}-${STACK_VERSION}-docker-build-context.tar.gz"
     done

.buildkite/scripts/dra/common.sh

@@ -22,6 +22,21 @@ function save_docker_tarballs {
     done
 }
 
+# normalized $ARCH should be either "amd64" or "arm64"
+function normalize_arch {
+    case "$ARCH" in
+        x86_64|amd64)
+            ARCH="amd64"
+            ;;
+        aarch64|arm64)
+            ARCH="arm64"
+            ;;
+        *)
+            error "Unsupported architecture: $ARCH"
+            ;;
+    esac
+}
+
 # Since we are using the system jruby, we need to make sure our jvm process
 # uses at least 1g of memory, If we don't do this we can get OOM issues when
 # installing gems. See https://github.com/elastic/logstash/issues/5179