use custom image. simplify script

Author: rubenruizdegauna

.buildkite/pipeline.agentless-tests.yaml

@@ -18,7 +18,10 @@ steps:
   - label: ":docker: Validate docker image is built for all architectures"
     command: ".buildkite/scripts/steps/validate-agentless-docker-image.sh"
     agents:
-      provider: "gcp"
+      provider: "docker.elastic.co/ci-agent-images/observability/oci-image-tools-agent:latest@sha256:a4ababd1347111759babc05c9ad5a680f4af48892784951358488b7e7fc94af9"
+    plugins:
+      - elastic/vault-docker-login#v0.6.1:
+          secret_path: 'kv/ci-shared/platform-ingest/elastic_docker_registry'
 
   - wait
 

.buildkite/scripts/steps/validate-agentless-docker-image.sh

@@ -23,53 +23,21 @@ REQUIRED_ARCHITECTURES=("amd64" "arm64")
 _SELF=$(dirname "$0")
 source "${_SELF}/../common.sh"
 
-setup_extract_sha() {
-    # Ensure repo is available - redirect output to /dev/null
-    if [ ! -d "serverless-gitops" ]; then
-        git clone --depth 1 [email protected]:elastic/serverless-gitops.git
-    else
-        (cd serverless-gitops && git pull)
-    fi
-
-    # Install yq for YAML parsing
-    go install github.com/mikefarah/yq/[email protected]
-}
-
-extract_sha() {
-    local env=$1
-    
-    # Extract first matching SHA for the environment pattern
-    yq eval ".services.agentless.versions | with_entries(select(.key | test(\"^${env}.*\"))) | to_entries | .[0].value // \"\"" serverless-gitops/services/agentless/versions.yaml
-}
-
-echo "--- :docker: Validating Docker image architectures"
-
-# Check environment variable
-if [ -z "${ENVIRONMENT:-}" ]; then
-    echo "ENVIRONMENT variable is not set"
-    exit 1
-fi
-
-setup_extract_sha
-
-# Extract the SHA for the specified environment
-COMMIT_SHA=$(extract_sha "$ENVIRONMENT")
-
-if [ -z "$COMMIT_SHA" ]; then
+if [ -z "$SERVICE_VERSION" ]; then
     echo "No SHA found for environment: $ENVIRONMENT"
     exit 1
 fi
 
-DOCKER_TAG="git-${COMMIT_SHA}"
+DOCKER_TAG="git-${SERVICE_VERSION}"
 PRIVATE_IMAGE="${PRIVATE_REPO}:${DOCKER_TAG}"
 
 echo "Environment: ${ENVIRONMENT}"
-echo "Commit SHA: ${COMMIT_SHA}"
+echo "Commit SHA: ${SERVICE_VERSION}"
 echo "Validating image: ${PRIVATE_IMAGE}"
 
 # Inspect the manifest to get architecture information
 echo "--- :mag: Inspecting image manifest"
-MANIFEST_OUTPUT=$(docker manifest inspect "$PRIVATE_IMAGE" 2>&1) || {
+MANIFEST_OUTPUT=$(skopeo inspect docker://"${PRIVATE_IMAGE}" --raw 2>&1) || {
     echo "Failed to inspect manifest for image: ${PRIVATE_IMAGE}"
     echo "Error: ${MANIFEST_OUTPUT}"
     exit 1