feat: new Mapper example which serves as a slow container for testing purposes

pkg/mapper/examples/cat_sleep/Dockerfile

@@ -0,0 +1,20 @@
+####################################################################################################
+# base
+####################################################################################################
+FROM alpine:3.20 AS base
+ARG TARGETARCH
+RUN apk update && apk upgrade && \
+    apk add ca-certificates && \
+    apk --no-cache add tzdata
+
+COPY dist/cat-sleep-example-${TARGETARCH} /bin/cat-sleep-example
+RUN chmod +x /bin/cat-sleep-example
+
+####################################################################################################
+# cat-sleep
+####################################################################################################
+FROM scratch AS cat-sleep
+COPY --from=base /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=base /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+COPY --from=base /bin/cat-sleep-example /bin/cat-sleep-example
+ENTRYPOINT [ "/bin/cat-sleep-example" ]

pkg/mapper/examples/cat_sleep/Makefile

@@ -0,0 +1,22 @@
+TAG ?= stable
+PUSH ?= false
+IMAGE_REGISTRY = quay.io/numaio/numaflow-go/map-cat-sleep:${TAG}
+ARCHITECTURES = amd64 arm64
+
+.PHONY: build
+build:
+	for arch in $(ARCHITECTURES); do \
+		CGO_ENABLED=0 GOOS=linux GOARCH=$${arch} go build -v -o ./dist/cat-sleep-example-$${arch} main.go; \
+	done
+
+.PHONY: image-push
+image-push: build
+	docker buildx build -t ${IMAGE_REGISTRY} --platform linux/amd64,linux/arm64 --target cat-sleep . --push
+
+.PHONY: image
+image: build
+	docker build -t ${IMAGE_REGISTRY} --target cat-sleep .
+	@if [ "$(PUSH)" = "true" ]; then docker push ${IMAGE_REGISTRY}; fi
+
+clean:
+	-rm -rf ./dist

pkg/mapper/examples/cat_sleep/README.md

@@ -0,0 +1,3 @@
+# Cat with Sleep
+
+An example User Defined Function that outputs the same value as the input, but first does a sleep. This example is for the purpose of performing testing with a slow vertex. 

pkg/mapper/examples/cat_sleep/go.mod

@@ -0,0 +1,17 @@
+module even_odd
+
+go 1.21
+
+replace github.com/numaproj/numaflow-go => ../../../..
+
+require github.com/numaproj/numaflow-go v0.9.0
+
+require (
+	golang.org/x/net v0.29.0 // indirect
+	golang.org/x/sync v0.8.0 // indirect
+	golang.org/x/sys v0.25.0 // indirect
+	golang.org/x/text v0.18.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 // indirect
+	google.golang.org/grpc v1.66.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
+)

pkg/mapper/examples/cat_sleep/go.sum

@@ -0,0 +1,24 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/net v0.29.0 h1:5ORfpBpCs4HzDYoodCDBbwHzdR5UrLBZ3sOnUJmFoHo=
+golang.org/x/net v0.29.0/go.mod h1:gLkgy8jTGERgjzMic6DS9+SP0ajcu6Xu3Orq/SpETg0=
+golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
+golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
+golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 h1:pPJltXNxVzT4pK9yD8vR9X75DaWYYmLGMsEvBfFQZzQ=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
+google.golang.org/grpc v1.66.0 h1:DibZuoBznOxbDQxRINckZcUvnCEvrW9pcWIE2yF9r1c=
+google.golang.org/grpc v1.66.0/go.mod h1:s3/l6xSSCURdVfAnL+TqCNMyTDAGN6+lZeVxnZR128Y=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

pkg/mapper/examples/cat_sleep/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/numaproj/numaflow-go/pkg/mapper"
+)
+
+const DEFAULT_SLEEP_SECONDS = 10
+
+type CatSleep struct {
+}
+
+func (e *CatSleep) Map(ctx context.Context, keys []string, d mapper.Datum) mapper.Messages {
+
+	// sleep for as long as the environment variable indicates (or default if not configured)
+	sleepSeconds := DEFAULT_SLEEP_SECONDS
+	secondsString := os.Getenv("SLEEP_SECONDS")
+	if secondsString == "" {
+		log.Printf("SLEEP_SECONDS environment variable not set, using default %d seconds\n", DEFAULT_SLEEP_SECONDS)
+	} else {
+		val, err := strconv.Atoi(secondsString)
+		if err != nil {
+			log.Printf("SLEEP_SECONDS environment variable %q not an int, using default %d seconds\n", secondsString, DEFAULT_SLEEP_SECONDS)
+		} else {
+			sleepSeconds = val
+		}
+	}
+	time.Sleep(time.Duration(sleepSeconds) * time.Second)
+	return mapper.MessagesBuilder().Append(mapper.NewMessage(d.Value()).WithKeys(keys))
+}
+
+func main() {
+	err := mapper.NewServer(&CatSleep{}).Start(context.Background())
+	if err != nil {
+		log.Panic("Failed to start map function server: ", err)
+	}
+}