Getting started with Gateway API Inference Extension¶

This quickstart guide is intended for engineers familiar with k8s and model servers (vLLM in this instance). The goal of this guide is to get a first, single InferencePool up and running!

Prerequisites¶

Envoy Gateway v1.2.1 or higher
A cluster with:
Support for Services of type LoadBalancer. (This can be validated by ensuring your Envoy Gateway is up and running). For example, with Kind, you can follow these steps.
3 GPUs to run the sample model server. Adjust the number of replicas in ./config/manifests/vllm/deployment.yaml as needed.

Steps¶

Deploy Sample Model Server¶

Create a Hugging Face secret to download the model meta-llama/Llama-2-7b-hf. Ensure that the token grants access to this model. Deploy a sample vLLM deployment with the proper protocol to work with the LLM Instance Gateway.

kubectl create secret generic hf-token --from-literal=token=$HF_TOKEN # Your Hugging Face Token with access to Llama2
kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/vllm/deployment.yaml

Install the Inference Extension CRDs¶

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/crd/bases/inference.networking.x-k8s.io_inferencepools.yaml
kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/crd/bases/inference.networking.x-k8s.io_inferencemodels.yaml

Deploy InferenceModel¶

Deploy the sample InferenceModel which is configured to load balance traffic between the tweet-summary-0 and tweet-summary-1 LoRA adapters of the sample model server.

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/inferencemodel.yaml

Update Envoy Gateway Config to enable Patch Policy**¶

Our custom LLM Gateway ext-proc is patched into the existing envoy gateway via EnvoyPatchPolicy. To enable this feature, we must extend the Envoy Gateway config map. To do this, simply run:

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/gateway/enable_patch_policy.yaml
kubectl rollout restart deployment envoy-gateway -n envoy-gateway-system

Additionally, if you would like to enable the admin interface, you can uncomment the admin lines and run this again.

Deploy Gateway¶

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/gateway/gateway.yaml

NOTE: This file couples together the gateway infra and the HTTPRoute infra for a convenient, quick startup. Creating additional/different InferencePools on the same gateway will require an additional set of: Backend, HTTPRoute, the resources included in the ./manifests/gateway/ext-proc.yaml file, and an additional ./manifests/gateway/patch_policy.yaml file. Should you choose to experiment, familiarity with xDS and Envoy are very useful.

Confirm that the Gateway was assigned an IP address and reports a Programmed=True status:

$ kubectl get gateway inference-gateway
NAME                CLASS               ADDRESS         PROGRAMMED   AGE
inference-gateway   inference-gateway   <MY_ADDRESS>    True         22s

Deploy the Inference Extension and InferencePool¶

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/ext_proc.yaml

Deploy Envoy Gateway Custom Policies¶

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/gateway/extension_policy.yaml
kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/gateway/patch_policy.yaml

NOTE: This is also per InferencePool, and will need to be configured to support the new pool should you wish to experiment further.

OPTIONALLY: Apply Traffic Policy¶

For high-traffic benchmarking you can apply this manifest to avoid any defaults that can cause timeouts/errors.

kubectl apply -f https://github.com/kubernetes-sigs/gateway-api-inference-extension/raw/main/config/manifests/gateway/traffic_policy.yaml

Try it out¶

Wait until the gateway is ready.

IP=$(kubectl get gateway/inference-gateway -o jsonpath='{.status.addresses[0].value}')
PORT=8081

curl -i ${IP}:${PORT}/v1/completions -H 'Content-Type: application/json' -d '{
"model": "tweet-summary",
"prompt": "Write as if you were a critic: San Francisco",
"max_tokens": 100,
"temperature": 0
}'