}

function retry() {
  local n=1
  local max=5
  local delay=5
  while true; do
    "$@" && break
    if [[ $n -lt $max ]]; then
      ((n++))
      log "Command failed. Attempt $n/$max:"
      sleep $delay;
    else
      log "The command has failed after $n attempts."  >&2
      return 2
    fi
  done
}

# load_cluster_topology function reads cluster configuration topology file and

ISTIO_ENVOY_ARM_RELEASE_URL=${ISTIO_ENVOY_ARM_RELEASE_URL:-${ISTIO_ENVOY_BASE_URL}/envoy-alpha-${ISTIO_ENVOY_LINUX_VERSION}-arm64.tar.gz}
SLEEP_TIME=60

printf "Verifying %s is available\n" "$ISTIO_ENVOY_RELEASE_URL"
until curl --output /dev/null --silent --head --fail "$ISTIO_ENVOY_RELEASE_URL"; do
    printf '.'
    sleep $SLEEP_TIME
done
printf '\n'

printf "Verifying %s is available\n" "$ISTIO_ENVOY_ARM_RELEASE_URL"