61 lines
1.3 KiB
Go
61 lines
1.3 KiB
Go
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// Copyright 2014 Google Inc. All rights reserved.
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// Use of this source code is governed by the Apache 2.0
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// license that can be found in the LICENSE file.
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package internal
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// This file has code for accessing metadata.
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//
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// References:
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// https://cloud.google.com/compute/docs/metadata
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import (
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"fmt"
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"io/ioutil"
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"net/http"
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"net/url"
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)
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const (
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metadataHost = "metadata"
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metadataPath = "/computeMetadata/v1/"
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)
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var (
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metadataRequestHeaders = http.Header{
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"Metadata-Flavor": []string{"Google"},
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}
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)
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// TODO(dsymonds): Do we need to support default values, like Python?
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func mustGetMetadata(key string) []byte {
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b, err := getMetadata(key)
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if err != nil {
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panic(fmt.Sprintf("Metadata fetch failed for '%s': %v", key, err))
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}
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return b
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}
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func getMetadata(key string) ([]byte, error) {
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// TODO(dsymonds): May need to use url.Parse to support keys with query args.
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req := &http.Request{
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Method: "GET",
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URL: &url.URL{
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Scheme: "http",
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Host: metadataHost,
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Path: metadataPath + key,
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},
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Header: metadataRequestHeaders,
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Host: metadataHost,
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}
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resp, err := http.DefaultClient.Do(req)
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if err != nil {
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return nil, err
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}
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defer resp.Body.Close()
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if resp.StatusCode != 200 {
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return nil, fmt.Errorf("metadata server returned HTTP %d", resp.StatusCode)
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}
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return ioutil.ReadAll(resp.Body)
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}
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