add s3 cache layer for seatmaps

cdk/lib/constructs/api-lambda-construct.ts

@@ -105,6 +105,7 @@ export class ApiLambdaConstruct extends Construct {
     props.dataBucket.grantRead(this.lambda, 'raw/ourairports_data/regions.csv');
     props.dataBucket.grantRead(this.lambda, 'raw/LH_Public_Data/airports.json');
     props.dataBucket.grantRead(this.lambda, 'raw/LH_Public_Data/aircraft.json');
+    props.dataBucket.grantReadWrite(this.lambda, 'tmp/seatmap/*');
 
     props.authBucket.grantReadWrite(this.lambda, 'authreq/*');
     props.authBucket.grantReadWrite(this.lambda, 'federation/*');

cdk/lib/stacks/data-stack.ts

@@ -29,6 +29,12 @@ export class DataStack extends cdk.Stack {
           noncurrentVersionExpiration: Duration.days(1),
           noncurrentVersionsToRetain: 2,
         },
+        {
+          enabled: true,
+          expiration: Duration.days(3),
+          noncurrentVersionExpiration: Duration.days(1),
+          prefix: 'tmp/',
+        },
       ],
     });
   }

go/api/data/handler.go

@@ -14,8 +14,10 @@ import (
 	"github.com/explore-flights/monorepo/go/common"
 	"github.com/explore-flights/monorepo/go/common/adapt"
 	"github.com/explore-flights/monorepo/go/common/lufthansa"
+	"github.com/explore-flights/monorepo/go/common/xtime"
 	"io"
 	"log/slog"
+	"net/http"
 	"slices"
 	"strconv"
 	"strings"
@@ -159,16 +161,19 @@ type Aircraft struct {
 type MinimalS3Client interface {
 	adapt.S3Getter
 	adapt.S3Lister
+	adapt.S3Putter
 }
 
 type Handler struct {
 	s3c    MinimalS3Client
+	lhc    *lufthansa.Client
 	bucket string
 }
 
-func NewHandler(s3c MinimalS3Client, bucket string) *Handler {
+func NewHandler(s3c MinimalS3Client, lhc *lufthansa.Client, bucket string) *Handler {
 	return &Handler{
 		s3c:    s3c,
+		lhc:    lhc,
 		bucket: bucket,
 	}
 }
@@ -415,6 +420,86 @@ func (h *Handler) Airlines(ctx context.Context, prefix string) ([]common.Airline
 	}), nil
 }
 
+func (h *Handler) SeatMap(ctx context.Context, fn common.FlightNumber, departureAirport, arrivalAirport string, departureDate xtime.LocalDate, cabinClass lufthansa.CabinClass) (*lufthansa.SeatAvailability, error) {
+	sm, found, err := h.loadSeatMapFromS3(ctx, fn, departureAirport, arrivalAirport, departureDate, cabinClass)
+	if err != nil {
+		return nil, err
+	}
+
+	if found {
+		slog.InfoContext(
+			ctx,
+			"loaded seatmap from s3 cache",
+			slog.String("fn", fn.String()),
+			slog.String("departureAirport", departureAirport),
+			slog.String("arrivalAirport", arrivalAirport),
+			slog.String("departureDate", departureDate.String()),
+			slog.String("cabinClass", string(cabinClass)),
+			slog.Bool("isNull", sm == nil),
+		)
+
+		return sm, nil
+	}
+
+	sm, err = h.loadSeatMapFromLH(ctx, fn, departureAirport, arrivalAirport, departureDate, cabinClass)
+	if err != nil {
+		return nil, err
+	}
+
+	s3Key := h.seatMapS3Key(fn, departureAirport, arrivalAirport, departureDate, cabinClass)
+	return sm, adapt.S3PutJson(ctx, h.s3c, h.bucket, s3Key, sm)
+}
+
+func (h *Handler) loadSeatMapFromLH(ctx context.Context, fn common.FlightNumber, departureAirport, arrivalAirport string, departureDate xtime.LocalDate, cabinClass lufthansa.CabinClass) (*lufthansa.SeatAvailability, error) {
+	sm, err := h.lhc.SeatMap(
+		ctx,
+		fn.String(),
+		departureAirport,
+		arrivalAirport,
+		departureDate,
+		cabinClass,
+	)
+
+	if err != nil {
+		var rse lufthansa.ResponseStatusErr
+		if errors.As(err, &rse) && rse.StatusCode == http.StatusNotFound {
+			return nil, nil
+		} else {
+			return nil, err
+		}
+	}
+
+	return &sm, nil
+}
+
+func (h *Handler) loadSeatMapFromS3(ctx context.Context, fn common.FlightNumber, departureAirport, arrivalAirport string, departureDate xtime.LocalDate, cabinClass lufthansa.CabinClass) (*lufthansa.SeatAvailability, bool, error) {
+	resp, err := h.s3c.GetObject(ctx, &s3.GetObjectInput{
+		Bucket: aws.String(h.bucket),
+		Key:    aws.String(h.seatMapS3Key(fn, departureAirport, arrivalAirport, departureDate, cabinClass)),
+	})
+
+	if err != nil {
+		if adapt.IsS3NotFound(err) {
+			return nil, false, nil
+		} else {
+			return nil, false, err
+		}
+	}
+
+	defer resp.Body.Close()
+
+	var sm *lufthansa.SeatAvailability
+	if err := json.NewDecoder(resp.Body).Decode(&sm); err != nil {
+		return nil, false, err
+	}
+
+	return sm, true, nil
+}
+
+func (h *Handler) seatMapS3Key(fn common.FlightNumber, departureAirport, arrivalAirport string, departureDate xtime.LocalDate, cabinClass lufthansa.CabinClass) string {
+	return fmt.Sprintf("tmp/seatmap/%s/%s/%s/%s/%s.json", fn.String(), departureAirport, arrivalAirport, departureDate.String(), cabinClass)
+}
+
 func (h *Handler) loadCsv(ctx context.Context, name string) (*csvReader, error) {
 	resp, err := h.s3c.GetObject(ctx, &s3.GetObjectInput{
 		Bucket: aws.String(h.bucket),

go/api/main.go

@@ -45,7 +45,7 @@ func main() {
 	}
 
 	connHandler := search.NewConnectionsHandler(fr)
-	dataHandler := data.NewHandler(s3c, bucket)
+	dataHandler := data.NewHandler(s3c, lhc, bucket)
 
 	e := echo.New()
 	e.Use(authHandler.Middleware)
@@ -71,7 +71,7 @@ func main() {
 	e.GET("/data/airports.json", web.NewAirportsEndpoint(dataHandler))
 	e.GET("/data/aircraft.json", web.NewAircraftEndpoint(dataHandler))
 	e.GET("/data/flight/:fn", web.NewFlightNumberEndpoint(dataHandler))
-	e.GET("/data/flight/:fn/seatmap/:departure/:arrival/:date/:aircraft", web.NewSeatMapEndpoint(dataHandler, lhc))
+	e.GET("/data/flight/:fn/seatmap/:departure/:arrival/:date/:aircraft", web.NewSeatMapEndpoint(dataHandler))
 
 	if err := run(ctx, e); err != nil {
 		panic(err)

go/api/web/data.go

@@ -44,7 +44,7 @@ func NewFlightNumberEndpoint(dh *data.Handler) echo.HandlerFunc {
 	}
 }
 
-func NewSeatMapEndpoint(dh *data.Handler, lhc *lufthansa.Client) echo.HandlerFunc {
+func NewSeatMapEndpoint(dh *data.Handler) echo.HandlerFunc {
 	return func(c echo.Context) error {
 		fnRaw := c.Param("fn")
 		departureAirport := strings.ToUpper(c.Param("departure"))
@@ -86,22 +86,21 @@ func NewSeatMapEndpoint(dh *data.Handler, lhc *lufthansa.Client) echo.HandlerFun
 		rawSeatMaps := make(map[lufthansa.CabinClass]lufthansa.SeatAvailability)
 
 		for _, cabinClass := range cabinClasses {
-			sm, err := lhc.SeatMap(
+			sm, err := dh.SeatMap(
 				c.Request().Context(),
-				fn.String(),
+				fn,
 				departureAirport,
 				arrivalAirport,
 				departureDate,
 				cabinClass,
 			)
 
 			if err != nil {
-				var rse lufthansa.ResponseStatusErr
-				if !errors.As(err, &rse) || rse.StatusCode != http.StatusNotFound {
-					return echo.NewHTTPError(http.StatusBadGateway, err)
-				}
-			} else {
-				rawSeatMaps[cabinClass] = sm
+				return echo.NewHTTPError(http.StatusInternalServerError)
+			}
+
+			if sm != nil {
+				rawSeatMaps[cabinClass] = *sm
 			}
 		}