function Get-InstanceMetadataAttribute {
  param (
    [parameter(Mandatory=$true)] [string]$Key,
    [parameter(Mandatory=$false)] [string]$Default
  )

  $url = ("http://metadata.google.internal/computeMetadata/v1/instance/" +
          "attributes/$Key")
  try {
    $client = New-Object Net.WebClient
    $client.Headers.Add('Metadata-Flavor', 'Google')
    return ($client.DownloadString($url)).Trim()
  }

  local zone="${1}"
  local name="${2}"
  local key="${3}"
  gcloud compute ssh "${name}" \
    --project "${PROJECT}" \
    --zone "${zone}" \
    --command "curl \"http://metadata.google.internal/computeMetadata/v1/instance/attributes/${key}\" -H \"Metadata-Flavor: Google\"" 2>/dev/null

  gcloud compute --project "${PROJECT}" ssh --zone "${ZONE}" "${NODE_NAMES[0]}" --command \
    "curl --fail --silent -H 'Metadata-Flavor: Google' \
      'http://metadata/computeMetadata/v1/instance/attributes/kube-env'" 2>/dev/null
}

# Read os distro information from /os/release on node.
# $1: The name of node
#
# Assumed vars:
#   PROJECT
#   ZONE
function get-node-os() {

function Get-InstanceMetadata {
  param (
    [parameter(Mandatory=$true)] [string]$Key,
    [parameter(Mandatory=$false)] [string]$Default
  )

  $url = "http://metadata.google.internal/computeMetadata/v1/instance/$Key"
  try {
    $client = New-Object Net.WebClient
    $client.Headers.Add('Metadata-Flavor', 'Google')
    return ($client.DownloadString($url)).Trim()
  }
  catch [System.Net.WebException] {

		}
		svcs := apps.All
		for _, src := range svcs {
			src := src
			t.NewSubTestf("from %v", src.Config().Service).Run(func(t framework.TestContext) {
				// curl -H "Metadata-Flavor: Google" 169.254.169.254/computeMetadata/v1/instance/service-accounts/default/identity
				opts := echo.CallOptions{
					Address: "169.254.169.254",
					Port:    echo.Port{ServicePort: 80},
					Scheme:  scheme.HTTP,
					HTTP: echo.HTTP{

  curl_cmd+=("${EXTRA_ADDONS_URL}")

  "${curl_cmd[@]}"
}

# A function that fetches a GCE metadata value and echoes it out.
# Args:
#   $1 : URL path after /computeMetadata/v1/ (without heading slash).
#   $2 : An optional default value to echo out if the fetch fails.
#
# NOTE: this function is duplicated in configure.sh, any changes here should be
# duplicated there as well.

    "curl --fail --silent -H 'Metadata-Flavor: Google' \
      'http://metadata/computeMetadata/v1/instance/attributes/kube-env'" 2>/dev/null
  gcloud compute --project "${PROJECT}" ssh --zone "${ZONE}" "${KUBE_MASTER}" --command \
    "curl --fail --silent -H 'Metadata-Flavor: Google' \
      'http://metadata/computeMetadata/v1/instance/attributes/kube-master-certs'" 2>/dev/null
}

    -Token ${kube_env}['KUBE_PROXY_TOKEN']
}

# Returns the IP alias range configured for this GCE instance.
function Get_IpAliasRange {
  $url = ("http://${GCE_METADATA_SERVER}/computeMetadata/v1/instance/" +
          "network-interfaces/0/ip-aliases/0")
  $client = New-Object Net.WebClient
  $client.Headers.Add('Metadata-Flavor', 'Google')
  return ($client.DownloadString($url)).Trim()
}