// Copyright 2024 Google LLC // // 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 compute import ( "log" "runtime" "strings" "sync" ) var ( vmOnGCEOnce sync.Once vmOnGCE bool ) // OnComputeEngine returns whether the client is running on GCE. // // This is a copy of the gRPC internal googlecloud.OnGCE() func at: // https://github.com/grpc/grpc-go/blob/master/internal/googlecloud/googlecloud.go // The functionality is similar to the metadata.OnGCE() func at: // https://github.com/xmenxk/google-cloud-go/blob/main/compute/metadata/metadata.go // // The difference is that OnComputeEngine() does not perform HTTP or DNS check on the metadata server. // In particular, OnComputeEngine() will return false on Serverless. func OnComputeEngine() bool { vmOnGCEOnce.Do(func() { mf, err := manufacturer() if err != nil { log.Printf("Failed to read manufacturer, vmOnGCE=false: %v", err) return } vmOnGCE = isRunningOnGCE(mf, runtime.GOOS) }) return vmOnGCE } // isRunningOnGCE checks whether the local system, without doing a network request, is // running on GCP. func isRunningOnGCE(manufacturer []byte, goos string) bool { name := string(manufacturer) switch goos { case "linux": name = strings.TrimSpace(name) return name == "Google" || name == "Google Compute Engine" case "windows": name = strings.Replace(name, " ", "", -1) name = strings.Replace(name, "\n", "", -1) name = strings.Replace(name, "\r", "", -1) return name == "Google" default: return false } }