github.com/jonaz/heapster@v1.3.0-beta.0.0.20170208112634-cd3c15ca3d29/common/gce/gce.go (about)

     1  // Copyright 2016 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package gce
    16  
    17  import (
    18  	"fmt"
    19  	"time"
    20  
    21  	"cloud.google.com/go/compute/metadata"
    22  	"github.com/golang/glog"
    23  )
    24  
    25  const (
    26  	waitForGCEInterval = 5 * time.Second
    27  	waitForGCETimeout  = 3 * time.Minute
    28  )
    29  
    30  func EnsureOnGCE() error {
    31  	for start := time.Now(); time.Since(start) < waitForGCETimeout; time.Sleep(waitForGCEInterval) {
    32  		glog.Infof("Waiting for GCE metadata to be available")
    33  		if metadata.OnGCE() {
    34  			return nil
    35  		}
    36  	}
    37  	return fmt.Errorf("not running on GCE")
    38  }