Container Service for Kubernetes:Deploy Knative Functions based on Knative

Step 1: Install the command-line tool

1. On the func release page, download the func binary file for your operating system.

   This topic uses Linux as an example to show how to install the func command-line tool.

2. After the download is complete, run the following command to rename the binary file to func.

   mv <path-to-binary-file> func # <path-to-binary-file> indicates the local path of the binary file, for example, func_darwin_amd64 or func_linux_amd64.

3. Run the following command to grant executable permissions on the binary file.

   chmod +x func

4. Run the following command to move the func command to a directory in the system PATH so that you can run the command from anywhere.

   mv func /usr/local/bin

5. Run the following command to verify that the func command-line tool is installed.

   func version

   If the version information of the installed func tool is displayed, the command-line tool is installed.

Step 2: Create a function

Knative Functions provides templates for multiple languages and invocation methods. The following templates are available for CloudEvent and HTTP invocations.

• Node.js

• Python

• Go

• Quarkus

• Rust

• Spring Boot

• TypeScript

The following example uses the Go template to show how to create a function.

1. Run the following command to create a function.

   func create -l <language> <function-name>

   For example, create a sample function in Go.

   func create -l go hello

   Expected output:

   Created go function in /usr/local/bin/hello

2. In the hello directory, run the ls command to view the created project directory.

   func.yaml  go.mod  handle.go  handle_test.go  README.md

3. In the hello directory, run the following command to view the automatically created func.yaml file.

   cat func.yaml

   Expected output:

   specVersion: 0.35.0
   name: hello
   runtime: go
   created: 2023-12-13T06:48:45.419587147Z

4. Edit the func.yaml file to customize the parameters for building and deployment for later use. The func.yaml file contains the configuration information of the function project. For details, see func_yaml.md.

   The following is a sample func.yaml file:

   specVersion: 0.35.0
   name: hello
   runtime: go
   created: 2023-11-29T14:47:34.101658+08:00
   registry: registry.cn-beijing.aliyuncs.com/knative-release-xxx
   image: registry.cn-beijing.aliyuncs.com/knative-release-xxx/hello:latest
   build:
     builderImages:
       pack: registry-cn-beijing.ack.aliyuncs.com/acs/knative-func-builder-jammy-tiny:latest
   deploy:
     namespace: default

   • registry: the target repository address to which the image is pushed after the build.

   • builderImages: the container used for image building, for example, registry-cn-beijing.ack.aliyuncs.com/acs/knative-func-builder-jammy-tiny:latest.

   • deploy: the deployment-related configurations, such as the namespace.

Step 3: Deploy Knative Functions

After you create a function, you can deploy Knative Functions directly.

1. Run the following command to deploy the function in the function project.

   deploy uses the function project name as the Knative Service name by default. When the function is built, the project name and the image repository name are used to construct the full image address of the function.

   func deploy

   Expected output

   Building function image
   Still building
   Still building
   Yes, still building
   Don't give up on me
   Still building
   This is taking a while
   Still building
   Still building
   Yes, still building
   Function built: registry.cn-beijing.aliyuncs.com/knative-release-xxx/hello:latest
   Pushing function image to the registry "registry.cn-beijing.aliyuncs.com" using the "xxx" user credentials
   Deploying function to the cluster
   Function deployed in namespace "default" and exposed at URL:
      http://hello.default.example.com

2. Run the following command to view function deployment information.

   func info

   Expected output:

   Function name:
     hello
   Function is built in image:
   
   Function is deployed in namespace:
     default
   Routes:
     http://hello.default.example.com

Step 4: Invoke Knative Functions

1. Map the Knative access gateway address to the domain name that you want to access by adding an entry to the hosts file.

   The following is a sample binding.

   121.xx.xxx.xx hello.default.example.com # 121.xx.xxx.xx: replace it with the gateway address of the Knative Service, and replace hello.default.example.com with your service domain name.

2. Run the following command to invoke the function.

   func invoke

   Expected output:

   POST / HTTP/1.1 hello.default.example.com
     Content-Type: application/json
     Forwarded: for=192.168.102.101;proto=http
     Knative-Serving-Default-Route: true
     X-Forwarded-Proto: http
     User-Agent: Go-http-client/1.1
     Content-Length: 25
     Accept-Encoding: gzip
     K-Proxy-Request: activator
     X-Forwarded-For: 192.168.102.101, 192.168.102.97
     X-Request-Id: 3d82cfc8-f9df-4935-84cd-c6561b4587f6
   Body:

   The expected output indicates that an HTTP request was sent to Knative Functions and the function invocation succeeded.

3. Run the following command to view the status of the pods in the cluster.

   kubectl get pod

   Expected output:

   NAME                                      READY   STATUS    RESTARTS   AGE
   hello-00001-deployment-7b65fcdc4c-gfcbp   2/2     Running   0          34

   The expected output indicates that the function invocation triggered the creation of a pod.