Getting Started with Nuclio on Google Kubernetes Engine (GKE)

On This Page

Follow this step-by-step guide to set up a Nuclio development environment that uses the Google Kubernetes Engine (GKE) and related Google Cloud Platform (GCP) tools.

Prerequisites

Before starting the set-up procedure, ensure that the following prerequisites are met:

  • You have a billable GKE project. For detailed information about GKE, see the GKE documentation.

    Note
    For simplicity, this guide uses the GKE project name nuclio-gke. Replace all reference to this name with the name of your GKE project.
  • The GCP CLI (gcloud) is installed and configured to work with your GKE project.

  • The GCR Docker credentials helper, (docker-credential-gcr) is installed. You can use this gcloud command to install it:

    gcloud components install docker-credential-gcr
    
  • The Google Container Registry (GCR) API is enabled on your project.

  • The Nuclio CLI (nuctl) is installed — if you wish to use the CLI to deploy Nuclio functions. To install the CLI, simply download the appropriate CLI version to your installation machine.

Set up a Kubernetes cluster and a local environment

Create a Kubernetes cluster by running the following gcloud command. Feel free to modify the options and parameters:

gcloud container clusters create nuclio --machine-type n1-standard-2 --image-type COS --disk-size 100 --num-nodes 2 --no-enable-legacy-authorization

Get the credentials of the cluster by running the following gcloud command. This command updates the kubeconfig file, which configures access to your cluster:

gcloud container clusters get-credentials nuclio

Assign cluster-admin permissions to your user to allow creation of role-based access control (RBAC) roles, in accordance with the GKE documentation:

Note
The first command, which sets GKE_USER, is just a method for retrieving your registered email address. This command requires jq. If you know your GCP registration email address, you can enter it manually; note that the email address is case sensitive.

GKE_USER=$(gcloud projects get-iam-policy "$(gcloud config list --format 'value(core.project)')" --format json \
           | jq -r '.bindings[] | select(.role == "roles/owner") | .members[]' \
           | awk -F':' '{print $2}')

kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin --user $GKE_USER

Verify your configuration by running the following kubectl command (see the Kubernetes documentation):

kubectl get pods --all-namespaces

Create a secret for GCR authentication: because Nuclio functions are images that need to be pushed and pulled to/from the registry, you need to create a secret that stores your registry credentials, and mount the secret to the Nuclio dashboard container so that it can be used to authenticate the Docker client with the GCR. Start by getting your service ID.

Note

You can use any private Docker registry:

Create a service-to-service key that allows GKE to access the GCR: this guide uses the key gcr.io. You can replace this with any of the supported sub domains, such as us.gcr.io if you want to force the US region:

gcloud iam service-accounts keys create credentials.json --iam-account $(gcloud iam service-accounts list --format "value(email)")

Install Nuclio

At this stage you should have a functioning Kubernetes cluster, credentials to a private Docker registry, and a working Kubernetes CLI (kubectl), and you can proceed to install the Nuclio services on the cluster (i.e., deploy Nuclio). For more information about kubectl, see the Kubernetes documentation.

Create a Nuclio namespace by running the following command:

Note
All Nuclio resources go into the "nuclio" namespace, and role-based access control (RBAC) is configured accordingly.
kubectl create namespace nuclio

Create a Kubernetes Docker-registry secret from service-key file that you created as part of the Kubernetes cluster setup, and delete this file:

kubectl create secret docker-registry registry-credentials \
    --namespace nuclio \
    --docker-username _json_key \
    --docker-password "$(cat credentials.json)" \
    --docker-server gcr.io \
    --docker-email ignored@nuclio.io

rm credentials.json

Create a registry configuration file: create a nuclio-registry ConfigMap file that will be used by the Nuclio dashboard to determine which repository should be used for pushing and pulling images:

kubectl create configmap --namespace nuclio nuclio-registry --from-literal=registry_url=gcr.io/$(gcloud config list --format 'value(core.project)')

Create the RBAC roles that are required for using Nuclio:

Note
You are encouraged to look at the nuclio-rbac.yaml file that's used in the following command before applying it, so that you don't get into the habit of blindly running things on your cluster (akin to running scripts off the internet as root).

kubectl apply -f https://raw.githubusercontent.com/nuclio/nuclio/master/hack/k8s/resources/nuclio-rbac.yaml

Deploy Nuclio to the cluster: The following command deploys the Nuclio controller and dashboard, among other resources:

kubectl apply -f https://raw.githubusercontent.com/nuclio/nuclio/master/hack/gke/resources/nuclio.yaml

Use the command kubectl get pods --namespace nuclio to verify both the controller and dashboard are running.

Forward the Nuclio dashboard port: the Nuclio dashboard publishes a service at port 8070. To use the dashboard, you first need to forward this port to your local IP address:

kubectl port-forward -n nuclio $(kubectl get pods -n nuclio -l nuclio.io/app=dashboard -o jsonpath='{.items[0].metadata.name}') 8070:8070

Deploy a function with the Nuclio dashboard

Browse to http://localhost:8070 (after having forwarded this port as part of the Nuclio installation) to see the Nuclio dashboard. Select the "default" project and then select New Function from the action toolbar to display the Create function page (http://localhost:8070/projects/default/create-function). Choose one of the predefined template functions, and select Deploy. The first build populates the local Docker cache with base images and other files, so it might take a while to complete, depending on your network. When the function deployment completes, you can select Test to invoke the function with a body.

Deploy a function with the Nuclio CLI (nuctl)

Run the following Nuclio CLI (nuctl) command from a command-line shell to deploy the example helloworld Go function. Replace the <URL> placeholder with the URL of your Docker registry. If you're using Docker Hub, the URL should include your username — docker.io/<username> — and you might also need to log into your Docker Hub account (docker login) on the installation machine before running the deployment command. You can add the --verbose flag if you want to peek under the hood.

nuctl deploy helloworld \
    --namespace nuclio \
    --path https://raw.githubusercontent.com/nuclio/nuclio/master/hack/examples/golang/helloworld/helloworld.go \
    --http-trigger-service-type nodePort \
    --registry <URL>
Note
The command in the previous code snippet exposes the function externally using a nodePort. This is done for demonstration purposes only. For more information about exposing your function, see Exposing a function.

When the function deployment completes, you can get the function information by running the following CLI command:

nuctl get function helloworld

Sample output -

  NAMESPACE | NAME        | PROJECT | STATE | NODE PORT | REPLICAS  
  nuclio    | helloworld  | default | ready |     42089 | 1/1   

You can see from the sample output that the deployed function helloworld is running and using port 42089.

Because the function is exposed using a nodePort, you can run the following CLI command to invoke it:

nuctl invoke helloworld --method POST --body '{"hello":"world"}' --content-type "application/json"

Sample output -

> Response headers:
Server = nuclio
Date = Thu, 18 Jun 2020 06:56:27 GMT
Content-Type = application/text
Content-Length = 21

> Response body:
Hello, from Nuclio :]

What's next?

See the following resources to make the best of your new Nuclio environment: