Add missing resolve-dra-manifest.sh for DRA build jobs

.ci/scripts/resolve-dra-manifest.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+set -e
+
+strip_version() {
+  echo $1 | sed -E "s/(.+)-[0-9a-f]+/\1/g"
+}
+
+fetch_build() {
+  curl -sS https://artifacts-$1.elastic.co/$2/latest/$3.json \
+    | jq -r '.build_id'
+}
+
+ARTIFACT="${ARTIFACT:-$1}"
+BRANCH="${BRANCH:-$2}"
+ES_VERSION="${ES_VERSION:-$3}"
+WORKFLOW=${WORKFLOW:-$4}
+
+LATEST_BUILD=$(fetch_build $WORKFLOW $ARTIFACT $BRANCH)
+LATEST_VERSION=$(strip_version $LATEST_BUILD)
+
+# If the latest artifact version doesn't match what we expect, try the corresponding version branch.
+# This can happen when the version of artifact has been bumped on the master branch.
+if [ "$LATEST_VERSION" != "$ES_VERSION" ]; then
+  echo "Latest build for '$ARTIFACT' is version $LATEST_VERSION but expected version $ES_VERSION." 1>&2
+  NEW_BRANCH=$(echo $ES_VERSION | sed -E "s/([0-9]+\.[0-9]+)\.[0-9]/\1/g")
+  echo "Using branch $NEW_BRANCH instead of $BRANCH." 1>&2
+  LATEST_BUILD=$(fetch_build $WORKFLOW $ARTIFACT $NEW_BRANCH)
+fi
+
+echo $LATEST_BUILD