added prometeus exporter

cmd/lambda/main.go

@@ -22,15 +22,11 @@ package main
 import (
 	"encoding/json"
 	"math/rand"
-	"strconv"
 	"strings"
 	"time"
 
 	"github.com/aws/aws-lambda-go/events"
 	"github.com/aws/aws-lambda-go/lambda"
-	"github.com/aws/aws-sdk-go/aws"
-	"github.com/aws/aws-sdk-go/aws/session"
-	"github.com/aws/aws-sdk-go/service/dynamodb"
 	"github.com/bitmaelum/bitmaelum-suite/pkg/hash"
 	"github.com/bitmaelum/key-resolver-go/internal"
 	"github.com/bitmaelum/key-resolver-go/internal/apigateway"
@@ -61,20 +57,25 @@ var handlerMapping = map[string]HandlerFunc{
 // HandleRequest checks the incoming route and calls the correct handler for it
 func HandleRequest(req events.APIGatewayV2HTTPRequest) (*events.APIGatewayV2HTTPResponse, error) {
 	if req.RouteKey == "GET /" {
-		logMetric(req.RouteKey, 200)
+		internal.LogMetric(req.RouteKey, 200)
 		return getIndex(req), nil
 	}
 
 	if req.RouteKey == "GET /config.json" {
-		logMetric(req.RouteKey, 200)
+		internal.LogMetric(req.RouteKey, 200)
+		return getConfig(req), nil
+	}
+
+	if req.RouteKey == "GET /prometheus-export" {
+		internal.LogMetric(req.RouteKey, 200)
 		return getConfig(req), nil
 	}
 
 	h, err := hash.NewFromHash(req.PathParameters["hash"])
 	if err != nil {
 		resp := http.CreateError("Incorrect hash address", 400)
 
-		logMetric(req.RouteKey, 400)
+		internal.LogMetric(req.RouteKey, 400)
 		return apigateway.HTTPToResp(resp), nil
 	}
 
@@ -91,38 +92,10 @@ func HandleRequest(req events.APIGatewayV2HTTPRequest) (*events.APIGatewayV2HTTP
 		httpResp = http.CreateError("Forbidden", 403)
 	}
 
-	logMetric(req.RouteKey, httpResp.StatusCode)
+	internal.LogMetric(req.RouteKey, httpResp.StatusCode)
 	return apigateway.HTTPToResp(httpResp), nil
 }
 
-/**
- * Increase metrics
- */
-func logMetric(path string, statusCode int) {
-	input := &dynamodb.UpdateItemInput{
-		ExpressionAttributeNames: map[string]*string{
-			"#hits": aws.String("hits"),
-		},
-		ExpressionAttributeValues: map[string]*dynamodb.AttributeValue{
-			":inc": {N: aws.String("1")},
-			":zero": {N: aws.String("0")},
-		},
-		TableName:        aws.String("prometheus"),
-		UpdateExpression: aws.String("SET #hits = if_not_exists(#hits, :zero) + :inc"),
-		Key: map[string]*dynamodb.AttributeValue{
-			"path_code": {S: aws.String(path + " " + strconv.Itoa(statusCode))},
-		},
-	}
-
-	sess := session.Must(session.NewSessionWithOptions(session.Options{
-		SharedConfigState: session.SharedConfigEnable,
-	}))
-	dyna := dynamodb.New(sess)
-
-	// Update logging
-	_, _ = dyna.UpdateItem(input)
-}
-
 func getIndex(_ events.APIGatewayV2HTTPRequest) *events.APIGatewayV2HTTPResponse {
 	headers := map[string]string{}
 	headers["Content-Type"] = "text/html"

internal/prometheus.go

@@ -0,0 +1,79 @@
+package internal
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/aws/aws-lambda-go/events"
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/dynamodb"
+)
+
+// LogMetric will log the given metric to the DynamoDB
+func LogMetric(path string, statusCode int) {
+	input := &dynamodb.UpdateItemInput{
+		ExpressionAttributeNames: map[string]*string{
+			"#hits": aws.String("hits"),
+		},
+		ExpressionAttributeValues: map[string]*dynamodb.AttributeValue{
+			":inc":  {N: aws.String("1")},
+			":zero": {N: aws.String("0")},
+		},
+		TableName:        aws.String("prometheus"),
+		UpdateExpression: aws.String("SET #hits = if_not_exists(#hits, :zero) + :inc"),
+		Key: map[string]*dynamodb.AttributeValue{
+			"path_code": {S: aws.String(path + " " + strconv.Itoa(statusCode))},
+		},
+	}
+
+	dyna := getDyna()
+
+	// Update logging
+	_, _ = dyna.UpdateItem(input)
+}
+
+// ExportMetric will return a JSON output with the exported JSON log
+func ExportMetric() *events.APIGatewayV2HTTPResponse {
+	headers := map[string]string{}
+
+	body := ""
+
+	input := &dynamodb.ScanInput{
+	    ExpressionAttributeNames: map[string]*string{
+	        "#path_code": aws.String("path_code"),
+	        "#hits": aws.String("hits"),
+	    },
+	    ProjectionExpression: aws.String("#path_code, #hits"),
+	    TableName:            aws.String("prometheus"),
+	}
+
+	dyna := getDyna()
+	result, err := dyna.Scan(input)
+	if err == nil {
+		for i := range result.Items {
+
+			s := result.Items[i]["path_code"].S
+			parts := strings.Split(*s, " ")
+
+			hits := result.Items[i]["hits"].N
+			body += fmt.Sprintf("keyresolver_request{method=\"%s\" path=\"%s\", code=%s} = %s\n", parts[0], parts[1], parts[2], *hits)
+		}
+	}
+
+	resp := &events.APIGatewayV2HTTPResponse{
+		StatusCode: 200,
+		Headers:    headers,
+		Body:       string(body),
+	}
+
+	return resp
+}
+
+func getDyna() *dynamodb.DynamoDB {
+	sess := session.Must(session.NewSessionWithOptions(session.Options{
+		SharedConfigState: session.SharedConfigEnable,
+	}))
+	return dynamodb.New(sess)
+}