added fly.io regional metrics capture for poktscan. This can be impro…

…ved upon in the future

gateway/common/config.go

@@ -24,6 +24,8 @@ const (
 	INSTRUMENT_ENABLED        = "ENABLE_INSTRUMENT"
 	LOG_LEVEL                 = "LOG_LEVEL"
 	LOG_HTTP_RESPONSE         = "LOG_HTTP_RESPONSE"
+	FLY_API_KEY               = "FLY_API_KEY"
+	FLY_GATEWAY_URI           = "FLY_GATEWAY_URI"
 )
 
 // This may evolve to include config outside env, or use .env file for

gateway/proxy/kitMetricsKitRouter.go

@@ -1,16 +1,66 @@
 package proxy
 
 import (
+	"compress/gzip"
+	"encoding/json"
 	"fmt"
 	"io"
+	log "log/slog"
 	"net/http"
+	"strings"
+
+	"porters/common"
 )
 
-func kitMetricsHandler(w http.ResponseWriter, r *http.Request, proxyToUrl string) {
+type Machine struct {
+	ID         string `json:"id"`
+	InstanceID string `json:"instance_id"`
+	Region     string `json:"region"`
+}
+
+func kitMetricsHandler(w http.ResponseWriter, r *http.Request, proxyToUrl, region string) {
+	flyApiKey := common.GetConfig(common.FLY_API_KEY)
+	// Fetch the machines from Fly.io
+	machines, err := fetchMachines(flyApiKey)
+	if err != nil {
+		http.Error(w, "Unable to retrieve machines from Fly.io", http.StatusInternalServerError)
+		return
+	}
+
+	// Find the machine for the given region
+	machineID := ""
+	for _, machine := range machines {
+		if strings.EqualFold(machine.Region, region) {
+			machineID = machine.ID
+			break
+		}
+	}
+
+	if machineID == "" {
+		http.Error(w, "Machine not found for the given region", http.StatusNotFound)
+		return
+	}
+
+	log.Info("Retrieved Machine ID for gatewaykit", "Machine ID", machineID)
+
+	// Construct the metrics URL
 	kitMetricsUrl := fmt.Sprintf("%s/metrics", proxyToUrl)
 
+	log.Info("Calling metrics endpoint", "kitMetricsUrl", kitMetricsUrl)
+
+	// Create a new HTTP request
+	req, err := http.NewRequest("GET", kitMetricsUrl, nil)
+	if err != nil {
+		http.Error(w, "Unable to create request", http.StatusInternalServerError)
+		return
+	}
+
+	// Add the fly-force-instance-id header
+	req.Header.Set("fly-force-instance-id", machineID)
+
 	// Forward the request to the kit's /metrics endpoint
-	resp, err := http.Get(kitMetricsUrl)
+	client := &http.Client{}
+	resp, err := client.Do(req)
 	if err != nil {
 		http.Error(w, "Unable to retrieve kit metrics", http.StatusInternalServerError)
 		return
@@ -21,3 +71,44 @@ func kitMetricsHandler(w http.ResponseWriter, r *http.Request, proxyToUrl string
 	w.WriteHeader(resp.StatusCode)
 	io.Copy(w, resp.Body)
 }
+
+func fetchMachines(authToken string) ([]Machine, error) {
+	flyGatewayMachines := common.GetConfig(common.FLY_GATEWAY_URI)
+	// Create a new request to fetch the machines
+	req, err := http.NewRequest("GET", flyGatewayMachines, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Set the Authorization header with the Bearer token
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", authToken))
+
+	// Perform the request
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	// Check if the response is gzipped and handle accordingly
+	var reader io.ReadCloser
+	if resp.Header.Get("Content-Encoding") == "gzip" {
+		reader, err = gzip.NewReader(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		defer reader.Close()
+	} else {
+		reader = resp.Body
+	}
+
+	// Decode the JSON response into the machines slice
+	var machines []Machine
+	err = json.NewDecoder(reader).Decode(&machines)
+	if err != nil {
+		return nil, err
+	}
+
+	return machines, nil
+}

gateway/proxy/mux.go

@@ -11,9 +11,9 @@ import (
 )
 
 const (
-    APP_PATH string = "appId"
-    PRODUCT_NAME    = "product"
-    HEALTH          = "health"
+	APP_PATH     string = "appId"
+	PRODUCT_NAME        = "product"
+	HEALTH              = "health"
 )
 
 func PluckAppId(req *http.Request) string {
@@ -48,8 +48,9 @@ func addMetricsRoute(r *mux.Router) *mux.Router {
 // Since the Gateway Kit is on an internal private network, with only the Gateway having access to it, we proxy a gateway-kit/metrics endpoint to expose the data to POKTScan
 func addMetricsKitRoute(r *mux.Router, proxyToUrl string) *mux.Router {
 	subrouter := r.PathPrefix("/gateway-kit/metrics").Subrouter()
-	subrouter.HandleFunc("", func(w http.ResponseWriter, r *http.Request) {
-		kitMetricsHandler(w, r, proxyToUrl)
+	subrouter.HandleFunc("/{region}", func(w http.ResponseWriter, r *http.Request) {
+		region := mux.Vars(r)["region"]
+		kitMetricsHandler(w, r, proxyToUrl, region)
 	})
 	return subrouter
 }