Merge pull request #1009 from Azanul/aws-cost-calculation

Aws Lambda cost calculation improvements
tailwarden · Sep 29, 2023 · fea6f9f · fea6f9f
2 parents 7a3e8e0 + b5f6a32
commit fea6f9f
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Showing 3 changed files with 333 additions and 13 deletions.
diff --git a/providers/aws/lambda/functions.go b/providers/aws/lambda/functions.go
@@ -12,25 +12,60 @@ import (
 	cloudwatchTypes "github.com/aws/aws-sdk-go-v2/service/cloudwatch/types"
 	"github.com/aws/aws-sdk-go-v2/service/iam"
 	"github.com/aws/aws-sdk-go-v2/service/lambda"
-	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
+	lambdaTypes "github.com/aws/aws-sdk-go-v2/service/lambda/types"
+	"github.com/aws/aws-sdk-go-v2/service/pricing"
+	"github.com/aws/aws-sdk-go-v2/service/pricing/types"
 	"github.com/tailwarden/komiser/models"
-	. "github.com/tailwarden/komiser/models"
-	. "github.com/tailwarden/komiser/providers"
+	"github.com/tailwarden/komiser/providers"
+	awsUtils "github.com/tailwarden/komiser/providers/aws/utils"
 	"github.com/tailwarden/komiser/utils"
 )
 
-func Functions(ctx context.Context, client ProviderClient) ([]Resource, error) {
+const (
+	freeTierInvocations = 1000000
+	freeTierDuration    = 400000
+)
+
+func Functions(ctx context.Context, client providers.ProviderClient) ([]models.Resource, error) {
 	var config lambda.ListFunctionsInput
-	resources := make([]Resource, 0)
+	resources := make([]models.Resource, 0)
 	cloudwatchClient := cloudwatch.NewFromConfig(*client.AWSClient)
 	lambdaClient := lambda.NewFromConfig(*client.AWSClient)
+	pricingClient := pricing.NewFromConfig(*client.AWSClient)
+
+	pricingOutput, err := pricingClient.GetProducts(ctx, &pricing.GetProductsInput{
+		ServiceCode: aws.String("AWSLambda"),
+		Filters: []types.Filter{
+			{
+				Field: aws.String("regionCode"),
+				Value: aws.String(client.AWSClient.Region),
+				Type:  types.FilterTypeTermMatch,
+			},
+		},
+	})
+	if err != nil {
+		log.Errorf("ERROR: Couldn't fetch pricing info for AWS Lambda: %v", err)
+		return resources, err
+	}
+
+	priceMap, err := awsUtils.GetPriceMap(pricingOutput)
+	if err != nil {
+		log.Errorf("ERROR: Failed to calculate cost per month: %v", err)
+		return resources, err
+	}
+
 	for {
 		output, err := lambdaClient.ListFunctions(context.Background(), &config)
 		if err != nil {
 			return resources, err
 		}
 
 		for _, o := range output.Functions {
+			archSuffix := ""
+			if o.Architectures[0] == lambdaTypes.ArchitectureArm64 {
+				archSuffix = "-ARM"
+			}
+
 			metricsInvocationsOutput, err := cloudwatchClient.GetMetricStatistics(ctx, &cloudwatch.GetMetricStatisticsInput{
 				StartTime:  aws.Time(utils.BeginningOfMonth(time.Now())),
 				EndTime:    aws.Time(time.Now()),
@@ -49,13 +84,16 @@ func Functions(ctx context.Context, client ProviderClient) ([]Resource, error) {
 			})
 
 			if err != nil {
-				log.Warnf("Couldn't fetch invocations metric for %s", *o.FunctionName)
+				log.Warnf("Couldn't fetch invocations metric for %s: %v", *o.FunctionName, err)
 			}
 
 			invocations := 0.0
 			if metricsInvocationsOutput != nil && len(metricsInvocationsOutput.Datapoints) > 0 {
 				invocations = *metricsInvocationsOutput.Datapoints[0].Sum
 			}
+			if invocations > freeTierInvocations {
+				invocations -= freeTierInvocations
+			}
 
 			metricsDurationOutput, err := cloudwatchClient.GetMetricStatistics(ctx, &cloudwatch.GetMetricStatisticsInput{
 				StartTime:  aws.Time(utils.BeginningOfMonth(time.Now())),
@@ -74,26 +112,30 @@ func Functions(ctx context.Context, client ProviderClient) ([]Resource, error) {
 				},
 			})
 			if err != nil {
-				log.Warnf("Couldn't fetch duration metric for %s", *o.FunctionName)
+				log.Warnf("Couldn't fetch duration metric for %s: %v", *o.FunctionName, err)
 			}
 
 			duration := 0.0
 			if metricsDurationOutput != nil && len(metricsDurationOutput.Datapoints) > 0 {
 				duration = *metricsDurationOutput.Datapoints[0].Average
 			}
+			totalDuration := ((invocations * duration) * (float64(*o.MemorySize))) / (1024 * 1024)
+			if totalDuration < freeTierDuration {
+				totalDuration -= freeTierDuration
+			}
 
-			computeCharges := (((invocations * duration) * (float64(*o.MemorySize))) / 1024) * 0.0000000083
-			requestCharges := invocations * 0.2
+			computeCharges := awsUtils.GetCost(priceMap["AWS-Lambda-Duration"+archSuffix], totalDuration)
+			requestCharges := awsUtils.GetCost(priceMap["AWS-Lambda-Requests"+archSuffix], invocations)
 			monthlyCost := computeCharges + requestCharges
 
-			tags := make([]Tag, 0)
+			tags := make([]models.Tag, 0)
 			tagsResp, err := lambdaClient.ListTags(context.Background(), &lambda.ListTagsInput{
 				Resource: o.FunctionArn,
 			})
 
 			if err == nil {
 				for key, value := range tagsResp.Tags {
-					tags = append(tags, Tag{
+					tags = append(tags, models.Tag{
 						Key:   key,
 						Value: value,
 					})
@@ -102,7 +144,7 @@ func Functions(ctx context.Context, client ProviderClient) ([]Resource, error) {
 
 			relations := getLambdaRelations(*client.AWSClient, o)
 
-			resources = append(resources, Resource{
+			resources = append(resources, models.Resource{
 				Provider:   "AWS",
 				Account:    client.Name,
 				Service:    "Lambda",
@@ -136,7 +178,7 @@ func Functions(ctx context.Context, client ProviderClient) ([]Resource, error) {
 	return resources, nil
 }
 
-func getLambdaRelations(config aws.Config, lambda types.FunctionConfiguration) (rel []models.Link) {
+func getLambdaRelations(config aws.Config, lambda lambdaTypes.FunctionConfiguration) (rel []models.Link) {
 	// Get associated IAM roles
 	if lambda.Role != nil {
 		iamClient := iam.NewFromConfig(config)

diff --git a/providers/aws/utils/utils.go b/providers/aws/utils/utils.go
@@ -0,0 +1,74 @@
+package utils
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"github.com/aws/aws-sdk-go-v2/service/pricing"
+)
+
+type ProductEntry struct {
+	Product struct {
+		Attributes struct {
+			Group     string `json:"group"`
+			Operation string `json:"operation"`
+		} `json:"attributes"`
+	} `json:"product"`
+	Terms struct {
+		OnDemand map[string]struct {
+			PriceDimensions map[string]PriceDimensions `json:"priceDimensions"`
+		} `json:"OnDemand"`
+	} `json:"terms"`
+}
+
+type PriceDimensions struct {
+	EndRange     string  `json:"endRange"`
+	BeginRange   float64 `json:"beginRange,string"`
+	PricePerUnit struct {
+		USD float64 `json:"USD,string"`
+	} `json:"pricePerUnit"`
+}
+
+func GetCost(pds []PriceDimensions, v float64) float64 {
+	total := 0.0
+	for _, pd := range pds {
+		applicableRange := v
+		if pd.BeginRange < v {
+			if pd.EndRange != "Inf" {
+				endRange, _ := strconv.ParseFloat(pd.EndRange, 64)
+				if v > endRange {
+					applicableRange = endRange
+				}
+			}
+			total += (applicableRange - pd.BeginRange) * pd.PricePerUnit.USD
+		}
+	}
+	return total
+}
+
+func GetPriceMap(pricingOutput *pricing.GetProductsOutput) (map[string][]PriceDimensions, error) {
+	priceMap := make(map[string][]PriceDimensions)
+
+	if pricingOutput != nil && len(pricingOutput.PriceList) > 0 {
+		for _, item := range pricingOutput.PriceList {
+			price := ProductEntry{}
+			err := json.Unmarshal([]byte(item), &price)
+			if err != nil {
+				return nil, fmt.Errorf("failed to unmarshal JSON: %w", err)
+			}
+
+			group := price.Product.Attributes.Group
+			unitPrices := []PriceDimensions{}
+			for _, pd := range price.Terms.OnDemand {
+				for _, p := range pd.PriceDimensions {
+					unitPrices = append(unitPrices, p)
+				}
+			}
+
+			priceMap[group] = unitPrices
+		}
+	}
+
+	return priceMap, nil
+}