From 1ac1ed41e65ac3265ac932768c17bb986274f5fc Mon Sep 17 00:00:00 2001 From: Andrew Dunham Date: Thu, 2 Mar 2023 13:25:58 -0500 Subject: [PATCH] util/cloudenv: add ApproximateLocation to Cloud This function will return the approximate location if running in a cloud environment with a known region. Currently only AWS is supported. Change-Id: Ic4f14de4c76c7bd37d71b4eb7813e97f3878ff59 --- util/cloudenv/cloudenv.go | 110 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) diff --git a/util/cloudenv/cloudenv.go b/util/cloudenv/cloudenv.go index 3c86339e4..03443c9ec 100644 --- a/util/cloudenv/cloudenv.go +++ b/util/cloudenv/cloudenv.go @@ -5,8 +5,10 @@ package cloudenv import ( + "bytes" "context" "encoding/json" + "io" "log" "net" "net/http" @@ -181,3 +183,111 @@ func getCloud() Cloud { // TODO: more, as needed. return "" } + +// ApproximateLocation returns the approximate geographic location of the +// region that the current cloud host is running in. +// +// If the current host is not running in the cloud, if cloud provider is not +// supported, or if the current region could not be determined, then (0, 0) +// will be returned. +func (c Cloud) ApproximateLocation() (lat, lon float64) { + switch c { + case AWS: + loc := getApproximateLocationAWS() + return loc.lat, loc.lon + case GCP: + // TODO + case Azure: + // TODO + } + return 0, 0 +} + +type location struct{ lat, lon float64 } + +var noLocation location + +var approximateAWSRegionLocation = map[string]location{ + "af-south-1": {-33.928992, 18.417396}, // "CPT" / Cape Town, South Africa + "ap-east-1": {22.2793278, 114.1628131}, // "HKG" / Hong Kong + "ap-northeast-1": {35.6812665, 139.757653}, // "NRT" / Tokyo, Japan + "ap-northeast-2": {37.5666791, 126.9782914}, // "ICN" / Seoul, Korea + "ap-northeast-3": {34.661629, 135.4999268}, // "KIX" / Osaka, Japan + "ap-south-1": {19.0785451, 72.878176}, // "BOM" / Mumbai, India + "ap-south-2": {17.38878595, 78.46106473}, // "HYD" / Hyderabad, India + "ap-southeast-1": {1.357107, 103.8194992}, // "SIN" / Singapore + "ap-southeast-2": {-33.8698439, 151.2082848}, // "SYD" / Sydney, Australia + "ap-southeast-3": {-6.1753942, 106.827183}, // "CGK" / Jakarta, Indonesia + "ap-southeast-4": {-37.8142176, 144.9631608}, // "MEL" / Melbourne, Australia + "ca-central-1": {45.5031824, -73.5698065}, // "YUL" / Montreal, Canada + "cn-north-1": {39.906217, 116.3912757}, // "BJS" / Beijing + "cn-northwest-1": {37.4999947, 105.1928783}, // "ZHY" / Zhongwei + "eu-central-1": {50.1106444, 8.6820917}, // "FRA" / Frankfurt, Germany + "eu-central-2": {47.3744489, 8.5410422}, // "ZRH" / Zurich, Switzerland + "eu-north-1": {59.3251172, 18.0710935}, // "ARN" / Stockholm, Sweden + "eu-south-1": {45.4641943, 9.1896346}, // "MXP" / Milan, Italy + "eu-south-2": {41.6521342, -0.8809428}, // "ZAZ" / Zaragoza, Spain + "eu-west-1": {53.3498006, -6.2602964}, // "DUB" / Dublin, Ireland + "eu-west-2": {51.5073359, -0.12765}, // "LHR" / London, England + "eu-west-3": {48.8588897, 2.32004102}, // "CDG" / Paris, France + "me-south-1": {26.1551249, 50.5344606}, // "BAH" / Bahrain + "sa-east-1": {-23.5506507, -46.6333824}, // "GRU" / São Paulo, Brazil + "us-east-1": {38.8950368, -77.0365427}, // "IAD" / Washington D.C., USA + "us-east-2": {39.9622601, -83.0007065}, // "CMH" / Columbus, Ohio, USA + "us-gov-east-1": {39.9622601, -83.0007065}, // "CMH" / Columbus, Ohio, USA + "us-gov-west-1": {45.5202471, -122.674194}, // "PDX" / Portland, Oregon, USA + "us-west-1": {37.7790262, -122.419906}, // "SFO" / San Francisco, California, USA + "us-west-2": {45.5202471, -122.674194}, // "PDX" / Portland, Oregon, USA + + // NOTE: it's not public where in Dubai this is + "me-central-1": {25.07428234, 55.18853865}, // Dubai +} + +func getApproximateLocationAWS() location { + const maxWait = 2 * time.Second + tr := &http.Transport{ + DisableKeepAlives: true, + Dial: (&net.Dialer{ + Timeout: maxWait, + }).Dial, + } + ctx, cancel := context.WithTimeout(context.Background(), maxWait) + defer cancel() + + req, err := http.NewRequestWithContext(ctx, "PUT", "http://"+CommonNonRoutableMetadataIP+"/latest/api/token", nil) + if err != nil { + return noLocation + } + req.Header.Set("X-aws-ec2-metadata-token-ttl-seconds", "30") + + res, err := tr.RoundTrip(req) + if err != nil { + return noLocation + } + token, err := io.ReadAll(res.Body) + res.Body.Close() + if err != nil { + return noLocation + } + + req, err = http.NewRequestWithContext(ctx, "GET", "http://"+CommonNonRoutableMetadataIP+"/latest/dynamic/instance-identity/document", nil) + if err != nil { + return noLocation + } + req.Header.Set("X-aws-ec2-metadata-token", string(bytes.TrimSpace(token))) + + res, err = tr.RoundTrip(req) + if err != nil { + return noLocation + } + defer res.Body.Close() + + var identityDocument struct { + Region string `json:"region"` + } + if err := json.NewDecoder(res.Body).Decode(&identityDocument); err != nil { + return noLocation + } + + return approximateAWSRegionLocation[identityDocument.Region] +}