Container Compute Service:Deploy Knative Functions based on Knative

Prerequisites

Before you begin, ensure that you have Knative deployed in your ACS cluster. See Deploy Knative.

Step 1: Install the func CLI

Download the func binary from the func releases page for your operating system.

The following example installs func on Linux:

1. Rename the binary to func:

   mv <path-to-binary-file> func

   Replace <path-to-binary-file> with the path to the downloaded binary, for example, func_linux_amd64.

2. Make the binary executable:

   chmod +x func

3. Move func to a directory on your PATH so it can be run from anywhere:

   mv func /usr/local/bin

4. Verify the installation:

   func version

   If version information is returned, the installation is complete.

Step 2: Create a function

Knative Functions supports the following runtimes for both HTTP and CloudEvent invocations:

The following example creates a Go function named hello:

1. Scaffold the function project:

   func create -l go hello

   Expected output:

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

2. Review the generated project files in the hello directory:

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

3. View the auto-generated func.yaml:

   cat func.yaml

   Expected output:

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

4. Edit func.yaml to configure the image registry and deployment namespace. The following example shows a customized configuration:

   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

   Field	Description
   registry	The container registry where the built image is pushed
   builderImages	The builder image used to build the function. Example: registry-cn-beijing.ack.aliyuncs.com/acs/knative-func-builder-jammy-tiny:latest
   deploy	Deployment configuration, including the namespace where the function is deployed

   For all available fields, see func_yaml.md.

Step 3: Deploy the function

Run the following command from inside the hello directory:

func deploy

The deploy command builds the container image, pushes it to the registry specified in func.yaml, and deploys the function as a Knative Service. The service name matches the function project name, and the full image address is generated from the project name and registry.

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

To verify the deployment, run:

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 the function

1. Add an entry to your hosts file to route the Knative Service domain name to the Knative gateway IP address:

   121.xx.xxx.xx hello.default.example.com

   Replace 121.xx.xxx.xx with the actual Knative gateway IP address, and hello.default.example.com with the domain name shown in the deployment output.

2. 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 output confirms that the HTTP request reached Knative Functions and the function was invoked successfully.

3. Confirm that pods were created after invocation:

   kubectl get pod

   Expected output:

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

What's next

For common issues and solutions when using Knative, see Knative FAQ.