openfunction - Apisix

Description

The openfunction Plugin is used to integrate APISIX with CNCF OpenFunction serverless platform.

This Plugin can be configured on a Route and requests will be sent to the configured OpenFunction API endpoint as the upstream.

Attributes

Name	Type	Required	Default	Valid values	Description
function_uri	string	True			function uri. For example, `https://localhost:30858/default/function-sample`.
ssl_verify	boolean	False	true		When set to `true` verifies the SSL certificate.
authorization	object	False			Authorization credentials to access functions of OpenFunction.
authorization.service_token	string	False			The token format is 'xx:xx' which supports basic auth for function entry points.
timeout	integer	False	3000 ms	[100, ...] ms	OpenFunction action and HTTP call timeout in ms.
keepalive	boolean	False	true		When set to `true` keeps the connection alive for reuse.
keepalive_timeout	integer	False	60000 ms	[1000,...] ms	Time is ms for connection to remain idle without closing.
keepalive_pool	integer	False	5	[1,...]	Maximum number of requests that can be sent on this connection before closing it.

:::note

The timeout attribute sets the time taken by the OpenFunction to execute, and the timeout for the HTTP client in APISIX. OpenFunction calls may take time to pull the runtime image and start the container. So, if the value is set too small, it may cause a large number of requests to fail.

:::

Prerequisites

Before configuring the plugin, you need to have OpenFunction running. Installation of OpenFunction requires a certain version Kubernetes cluster. For details, please refer to Installation.

Create and Push a Function

You can then create a function following the sample

You'll need to push your function container image to a container registry like Docker Hub or Quay.io when building a function. To do that, you'll need to generate a secret for your container registry first.

shell

REGISTRY_SERVER=https://index.docker.io/v1/ REGISTRY_USER= ${your_registry_user} REGISTRY_PASSWORD= ${your_registry_password}
kubectl create secret docker-registry push-secret \
    --docker-server=$REGISTRY_SERVER \
    --docker-username=$REGISTRY_USER \
    --docker-password=$REGISTRY_PASSWORD

Enable the Plugin

You can now configure the Plugin on a specific Route and point to this running OpenFunction service:

:::note You can fetch the admin_key from config.yaml and save to an environment variable with the following command:

bash

admin_key=$(yq '.deployment.admin.admin_key[0].key' conf/config.yaml | sed 's/"//g')

:::

shell

curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri": "/hello",
    "plugins": {
        "openfunction": {
            "function_uri": "http://localhost:3233/default/function-sample/test",
            "authorization": {
                "service_token": "test:test"
            }
        }
    }
}'

Example usage

Once you have configured the plugin, you can send a request to the Route and it will invoke the configured function:

shell

curl -i http://127.0.0.1:9080/hello

This will give back the response from the function:

hello, test!

Configure Path Transforming

The OpenFunction Plugin also supports transforming the URL path while proxying requests to the OpenFunction API endpoints. Extensions to the base request path get appended to the function_uri specified in the Plugin configuration.

:::info IMPORTANT

The uri configured on a Route must end with * for this feature to work properly. APISIX Routes are matched strictly and the * implies that any subpath to this URI would be matched to the same Route.

:::

The example below configures this feature:

shell

curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri": "/hello/*",
    "plugins": {
        "openfunction": {
            "function_uri": "http://localhost:3233/default/function-sample",
            "authorization": {
                "service_token": "test:test"
            }
        }
    }
}'

Now, any requests to the path hello/123 will invoke the OpenFunction, and the added path is forwarded:

shell

curl  http://127.0.0.1:9080/hello/123

shell

Hello, 123!

Delete Plugin

To remove the openfunction Plugin, you can delete the corresponding JSON configuration from the Plugin configuration. APISIX will automatically reload and you do not have to restart for this to take effect.

shell

curl http://127.0.0.1:9180/apisix/admin/routes/1  -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "methods": ["GET"],
    "uri": "/index.html",
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:1980": 1
        }
    }
}'