/
metadata.go
63 lines (53 loc) · 1.63 KB
/
metadata.go
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// Copyright 2019 Authors of Cilium
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metadata
import (
"fmt"
"io/ioutil"
"net/http"
)
func getMetadata(name string) (string, error) {
resp, err := http.Get("http://169.254.169.254/latest/meta-data/" + name)
if err != nil {
return "", fmt.Errorf("unable to retrieve instance-id from metadata server: %s", err)
}
defer resp.Body.Close()
instanceID, err := ioutil.ReadAll(resp.Body)
if err != nil {
return "", fmt.Errorf("unable to read response body: %s", err)
}
return string(instanceID), nil
}
// GetInstanceMetadata returns the instance ID and type
func GetInstanceMetadata() (instanceID, instanceType, availabilityZone, vpcID string, err error) {
instanceID, err = getMetadata("instance-id")
if err != nil {
return
}
instanceType, err = getMetadata("instance-type")
if err != nil {
return
}
eth0MAC, err := getMetadata("mac")
if err != nil {
return
}
vpcIDPath := fmt.Sprintf("network/interfaces/macs/%s/vpc-id", eth0MAC)
vpcID, err = getMetadata(vpcIDPath)
if err != nil {
return
}
availabilityZone, err = getMetadata("placement/availability-zone")
return
}