echo "Environment variables not set. Make sure you run through the makefile (\`make init\`) rather than directly."
  exit 1
fi

# Setup arch suffix for envoy binary. For backwards compatibility, amd64 has no suffix.
if [[ "${TARGET_ARCH}" == "amd64" ]]; then
	ISTIO_ENVOY_ARCH_SUFFIX=""
else
	ISTIO_ENVOY_ARCH_SUFFIX="-${TARGET_ARCH}"
fi

# Populate the git version for istio/proxy (i.e. Envoy)

  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

    if ! grep -Eq "${failureRegex}" "${tmpFile}"; then
      fail "Unexpected failure"
    fi
    if [[ $n -lt $max ]]; then
      ((n++))
      echo "Command failed. Attempt $n/$max:"
    else
      fail "The command has failed after $n attempts."
    fi
  done
}