github.phpd.cn/cilium/cilium@v1.6.12/pkg/aws/metadata/metadata.go (about) 1 // Copyright 2019 Authors of Cilium 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 metadata 16 17 import ( 18 "fmt" 19 "io/ioutil" 20 "net/http" 21 ) 22 23 func getMetadata(name string) (string, error) { 24 resp, err := http.Get("http://169.254.169.254/latest/meta-data/" + name) 25 if err != nil { 26 return "", fmt.Errorf("unable to retrieve instance-id from metadata server: %s", err) 27 } 28 29 defer resp.Body.Close() 30 instanceID, err := ioutil.ReadAll(resp.Body) 31 if err != nil { 32 return "", fmt.Errorf("unable to read response body: %s", err) 33 } 34 35 return string(instanceID), nil 36 } 37 38 // GetInstanceMetadata returns the instance ID and type 39 func GetInstanceMetadata() (instanceID, instanceType, availabilityZone, vpcID string, err error) { 40 instanceID, err = getMetadata("instance-id") 41 if err != nil { 42 return 43 } 44 45 instanceType, err = getMetadata("instance-type") 46 if err != nil { 47 return 48 } 49 50 eth0MAC, err := getMetadata("mac") 51 if err != nil { 52 return 53 } 54 55 vpcIDPath := fmt.Sprintf("network/interfaces/macs/%s/vpc-id", eth0MAC) 56 vpcID, err = getMetadata(vpcIDPath) 57 if err != nil { 58 return 59 } 60 61 availabilityZone, err = getMetadata("placement/availability-zone") 62 return 63 }