--- title: "OpenFaaS for Kubernetes | Hostman Docs" description: "Learn how to deploy OpenFaaS on Kubernetes and build a serverless environment for running functions at scale. Step-by-step guide covers installation, CLI setup, ingress configuration, deploying built-in and custom functions, and integrating with Docker Hub for production-ready FaaS workflows." --- > For the complete documentation index for AI agents, see [llms.txt](https://hostman.com/llms.txt). OpenFaaS is an open-source platform for running functions (FaaS) on top of Kubernetes. It simplifies the deployment of small code units that execute on demand or in response to events. At its core, OpenFaaS follows the Function as a Service (FaaS) model: you write a function, package it into a Docker image, and OpenFaaS handles scaling, networking, and lifecycle management. It offers a user-friendly web interface and a command-line tool called `faas-cli`. You can write functions in popular languages such as Python, Node.js, Go, and others using pre-built templates. The complete documentation for OpenFaaS on Kubernetes is available on the [official website](https://docs.openfaas.com/). ## Installing the Addon To install OpenFaaS: 1. Go to the **Kubernetes** section and click on your cluster. 2. In the **Addons** tab, click **OpenFaaS**. 3. In the **Configuration** window, find the `ingress` section and enable it by setting `enabled: true`. Also, specify your domain in the `host` parameter. This will simplify access to the dashboard and allow usage of `faas-cli`. If you enable `ingress`, you can disable `exposeServices`, which is used by default. 4. Once parameters are set, click **Install** and wait for the installation to finish. To verify everything is running, check the status of pods in the `openfaas-fn` namespace: ```shell kubectl get pods -n openfaas-fn ``` Example output: ```shell NAME READY STATUS RESTARTS AGE alertmanager-57767d864c-hdqdn 1/1 Running 0 19h gateway-5f9c4b5754-ksr6x 2/2 Running 1 (19h ago) 19h nats-6ddf479847-dxr2g 1/1 Running 0 19h prometheus-6cbd946f66-wqdf8 1/1 Running 0 19h queue-worker-57c7479989-bw282 1/1 Running 0 19h ``` If all pods are in `Running` status, the installation was successful. ## Installing the CLI To work with OpenFaaS from the terminal, you need the `faas-cli` tool. It allows you to create functions, build and push images, deploy them to the cluster, invoke functions, and check their status. It is available for Linux, macOS, and Windows. Use the following commands to install it: **Linux/macOS** ```shell curl -sSL https://cli.openfaas.com | sh ``` **macOS** ```shell curl -sSL https://cli.openfaas.com | sh ``` Or, via Homebrew: ```shell brew install faas-cli ``` **Windows (PowerShell)** ```shell $version = (Invoke-WebRequest "https://api.github.com/repos/openfaas/faas-cli/releases/latest" | ConvertFrom-Json)[0].tag_name (New-Object System.Net.WebClient).DownloadFile("https://github.com/openfaas/faas-cli/releases/download/$version/faas-cli.exe", "faas-cli.exe") ``` Verify the installation: ```shell faas-cli version ``` ## Example Usage In this example, we will: - Deploy the OpenFaaS addon. - Bind a domain for easy dashboard access and CLI use. - Deploy a function from the built-in store. - Create and deploy a custom function using Docker Hub. Requirements: - A domain or subdomain for OpenFaaS access. - Installed Nginx Ingress addon. - A Docker Hub account (for custom functions). - Installed `faas-cli` and Docker. #### Deploying the Addon Go to the dashboard and install the **OpenFaaS** addon. In the **Configuration** section, enable `ingress` by setting `enabled: true` and specifying your domain in the `host` field. Then start the installation. #### Creating a Load Balancer Create a `loadbalancer.yaml` manifest: ```yaml apiVersion: v1 kind: Service metadata: name: ingress-nginx-lb namespace: ingress-nginx spec: selector: app.kubernetes.io/name: ingress-nginx type: LoadBalancer ports: - name: http port: 80 targetPort: 80 appProtocol: k8s.hostman.com/proto-http - name: https port: 443 targetPort: 443 appProtocol: k8s.hostman.com/proto-https ``` Apply it: ```shell kubectl apply -f loadbalancer.yaml ``` Set the balancer’s IP as the A record of your domain. If you're using Hostman NS servers, just select the newly created load balancer. Otherwise, get its IP manually: ```shell kubectl get svc --all-namespaces --field-selector spec.type=LoadBalancer ``` The IP will be under the `EXTERNAL-IP` column. Visit the domain you configured—a basic auth prompt will appear. Use the login `admin` and retrieve the password using: ```shell kubectl -n openfaas-fn get secret basic-auth -o jsonpath="{.data.basic-auth-password}" | base64 --decode ``` After logging in, the dashboard will open. ![E036c968 493b 4791 Ab5a C7966782647e.png](https://content.hostman.com/assets/8dbdb2f7-c1d7-4088-96d2-97ec77ec8b08.png?width=2894&height=848) _[OpenFaaS](https://www.openfaas.com/) Dashboard_ #### Working with Functions Let’s move on to using functions. We’ll install a function from the built-in OpenFaaS store. First, log in via the CLI. This will allow you to run commands related to function management: ```shell faas-cli login \ --gateway http:// \ --username admin \ --password ``` Where: - `domain` — the address specified during OpenFaaS installation; - `admin` — the default username; - `password` — the password can be retrieved with the following command: ```shell kubectl -n openfaas-fn get secret basic-auth -o jsonpath="{.data.basic-auth-password}" | base64 --decode ``` Now install the `figlet` function, which converts text into ASCII art: ```shell faas-cli store deploy figlet \   --gateway http:// ``` Make sure the function has been installed: ```shell faas-cli list \   --gateway http:// ``` The list will now contain the `figlet` function with a status of `Ready`. Invoke the function and pass a string as input: ```shell echo "Hostman" | faas-cli invoke figlet \   --gateway http:// ``` You’ll receive ASCII art with the given text in response. Now let’s go over deploying a custom function. Choose a template: ```shell faas-cli template store list ``` Create a new function based on the desired template—for example, `python3-http`: ```shell faas-cli new hello-k8s --lang python3-http ``` The following will be created: - `hello-k8s/handler.py` — the function code; - `stack.yaml` — the function manifest. Before building, edit the `stack.yaml` file and specify the path to your Docker Hub image. For example: ```yaml functions: hello-k8s: lang: python3-http handler: ./hello-k8s image: dockerhubuser/hello-k8s:latest ``` In the image `field`, specify your Docker Hub username and the image name. Note that OpenFaaS Community Edition only supports public images. Build the image: ```shell faas-cli build -f stack.yaml ``` After the image is built, push it to Docker Hub: ```shell faas-cli push -f stack.yaml ``` Finally, deploy the function to your cluster: ```shell faas-cli deploy -f stack.yaml \   --gateway http:// ``` After running the command, you’ll get a link to access the function. ![67ed7fe8 9a22 4515 Aeb8 0e9f49c8a07e.png](https://content.hostman.com/assets/0854d11f-63bb-4a4f-b3c4-c848c42e4406.png?width=1550&height=282) Open the link. You should see the message "Hello from OpenFaaS!".