LangStream

Quick Start

Run in local Kubernetes (minikube)

Requirements

Minikube
Helm
Docker
Java 17

brew install minikube
minikube start

Deploy MinIO (S3 BlobStorage implementation for local testing)

kubectl apply -f helm/examples/minio-dev.yaml

Deploy Kafka:

kubectl create namespace kafka
kubectl create -f 'https://strimzi.io/install/latest?namespace=kafka' -n kafka
kubectl apply -f https://strimzi.io/examples/latest/kafka/kafka-persistent-single.yaml -n kafka

NOTE: If the kubectl apply times out then you should take a look at your cluster with k9s -A and probably wait.

Deploy the LangStream Control Plane and the operator:

helm install langstream helm/langstream --values helm/examples/simple.yaml --wait --timeout 60s

NOTE: If the helm install times out then you should take a look at your cluster with k9s -A and possibly try with a larger timeout value.

Port forward control plane and the gateway to localhost:

kubectl port-forward svc/langstream-control-plane 8090:8090 &
kubectl port-forward svc/langstream-api-gateway 8091:8091 &

Wait for Kafka to be up and running:

kubectl wait kafka/my-cluster --for=condition=Ready --timeout=300s -n kafka

Create a sample app using the CLI:


OPEN_AI_URL=xx
OPEN_AI_ACCESS_KEY=xx

echo """
secrets:
  - name: open-ai
    id: open-ai
    data:
      url: $OPEN_AI_URL
      access-key: $OPEN_AI_ACCESS_KEY
""" > /tmp/secrets.yaml

./bin/langstream apps deploy test -app examples/applications/compute-openai-embeddings -i examples/instances/kafka-kubernetes.yaml -s /tmp/secrets.yaml 
./bin/langstream apps get test

Check your k8s cluster with k9s -A or run ./bin/langstream apps get test until the app is deployed.

Start producing messages:

kubectl -n kafka run kafka-producer -ti --image=quay.io/strimzi/kafka:0.35.1-kafka-3.4.0 --rm=true --restart=Never -- bin/kafka-console-producer.sh --bootstrap-server my-cluster-kafka-bootstrap:9092 --topic input-topic

Insert a JSON with "name" and "description":

{"name": "test", "description": "test"}

In another terminal:

kubectl -n kafka run kafka-consumer -ti --image=quay.io/strimzi/kafka:0.35.1-kafka-3.4.0 --rm=true --restart=Never -- bin/kafka-console-consumer.sh --bootstrap-server my-cluster-kafka-bootstrap:9092 --topic output-topic --from-beginning

Building the docker images locally

Build docker images and push them into the minikube environment

./docker/build.sh
minikube image load datastax/langstream-cli:latest-dev
minikube image load datastax/langstream-deployer:latest-dev
minikube image load datastax/langstream-control-plane:latest-dev
minikube image load datastax/langstream-runtime:latest-dev
minikube image load datastax/langstream-api-gateway:latest-dev

If you want to use the docker images you just built, use helm/examples/local.yaml values file:

helm install langstream helm/langstream --values helm/examples/local.yaml --wait --timeout 60s

Deploying to GKE or similar K8s test cluster

Instead of minio-dev.yaml use the helm/examples/minio-gke.yaml file:

kubectl apply -f helm/examples/minio-gke.yaml

Deploying to a Persistent Cluster

TODO: instructions on configuring with S3.