fix(RELEASE-1004): fix various multi-arch issues (#474)

- revert to using single oras_arg
- properly obtain origin_digest with platform arg since we want manifest
  index image

Signed-off-by: Scott Hebert <[email protected]>

tasks/push-snapshot/push-snapshot.yaml

@@ -117,13 +117,11 @@ spec:
  oras_args=()
  if [[ "$media_type" == "application/vnd.docker.distribution.manifest.list.v2+json" ]]\
  || [[ "$media_type" == "application/vnd.oci.image.index.v1+json" ]]; then
- # need to add separately or else the args get treated as 1 argument
- # and oras complains about "Error: unknown flag: --platform linux/amd64"
- oras_args+=("--platform")
- oras_args+=("$os/$arch")
+ oras_args+=("--platform $os/$arch")
  fi
 
- origin_digest=$(oras resolve --registry-config "$AUTH_FILE" "${oras_args[@]}" "${containerImage}" 2>/dev/null)
+ # we do not use oras_args here since we want to get the manifest index image digest
+ origin_digest=$(oras resolve --registry-config "$AUTH_FILE" "${containerImage}" 2>/dev/null)
 
  RESULTS_JSON=$(jq --arg i "$i" --argjson arches "$arches" --argjson oses "$oses" --arg name "$name" \
  --arg sha "$origin_digest" \
@@ -142,8 +140,8 @@ spec:
  # Calculate the source container image based on the provided container image
  sourceContainer="${source_repo}:${source_tag}"
  # Check if the source container exists
- source_container_digest=$(oras resolve --registry-config "$AUTH_FILE" "${oras_args[@]}" \
- "${sourceContainer}" 2>/dev/null)
+ source_container_digest=$(oras resolve --registry-config "$AUTH_FILE" \
+ "${sourceContainer}" ${oras_args[@]} 2>/dev/null)
 
  if [ -z "$source_container_digest" ] ; then
  echo "Error: Source container ${sourceContainer} not found!"