ISTIO_ENVOY_DEBUG_URL="${ISTIO_ENVOY_DEBUG_URL:-${ISTIO_ENVOY_BASE_URL}/envoy-debug-${ISTIO_ENVOY_VERSION}${ISTIO_ENVOY_ARCH_SUFFIX}.tar.gz}"
ISTIO_ENVOY_RELEASE_URL="${ISTIO_ENVOY_RELEASE_URL:-${ISTIO_ENVOY_BASE_URL}/envoy-alpha-${ISTIO_ENVOY_VERSION}${ISTIO_ENVOY_ARCH_SUFFIX}.tar.gz}"

# Envoy Linux vars.
ISTIO_ENVOY_LINUX_VERSION="${ISTIO_ENVOY_LINUX_VERSION:-${ISTIO_ENVOY_VERSION}}"

ISTIO_ENVOY_BASE_URL=${ISTIO_ENVOY_BASE_URL:-https://storage.googleapis.com/istio-build/proxy}
ISTIO_ENVOY_RELEASE_URL=${ISTIO_ENVOY_RELEASE_URL:-${ISTIO_ENVOY_BASE_URL}/envoy-alpha-${ISTIO_ENVOY_LINUX_VERSION}.tar.gz}
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"

else
  SHA=$(grep "istio.io/api" go.mod | head -n1 | awk '{ print $2 }')
  if [[ ${SHA} == *"-"* && ! ${SHA} =~ -rc.[0-9]$ && ! ${SHA} =~ -beta.[0-9]$ && ! ${SHA} =~ -alpha.[0-9]$ ]]; then
    # not an official release or release candidate, so get the commit sha
    SHA=$(echo "${SHA}" | awk -F '-' '{ print $NF }')
  fi
fi

if [ -z "${SHA}" ]; then