knative-lambda-runtime: A Python repository from mparaz

Knative Lambda Runtimes (e.g KLR, pronounced clear) are Tekton Tasks that can be used to run an AWS Lambda function in a Kubernetes cluster installed with Knative.

The execution environment where the AWS Lambda function runs is a clone of the AWS Lambda cloud environment thanks to a custom AWS runtime interface and some inspiration from the LambCI project.

With these templates, you can run your AWS Lambda functions as is in a Knative powered Kubernetes cluster.

The examples below use the tm CLI to interact with Knative but one could also use kubectl.

Docker registry for builds

To combine the runtime with your source, the examples below produce a new Docker image each time. While these images can be considered temporary, builds must be pushed to a Docker registry in order for Kubernetes to be able to pull. By default tm uses Knative Local Registry, equivalent to adding --registry-host knative.registry.svc.cluster.local to the commands below, so that builds can run without registry authentication. To override, set --registry-secret according to tm docs.

Concurrency

Concurrency in KLR represented by two components: parallel running bootstrap processes per container and Knative container concurrency model. By default AWS runtime interface fires up 8 bootstrap processes (functions, in other words) and allows multiple concurrent requests (containerConcurrency: 0) to be handled by each container. Default concurrency configuration can be changed on function deployment or update using tm deploy service command parameters:

--concurrency <N> - sets Knative service containerConcurrency value to N

--build-argument INVOKER_COUNT=<N> - passes number of parallel running functions to AWS lambda runtime

Values for these two parameters should be calculated individually for each function and depends on operation characteristics. Knative autoscaling is another important factor that affects service performance, but right now KLR uses default autoscaling configuration.

Examples

NOTE: all examples below work with Local Registry. If you don't have local registry in knative cluster, you can use external registry as discribed in CLI documentation

Python

Install runtime

tm deploy task -f https://raw.githubusercontent.com/triggermesh/knative-lambda-runtime/master/python-3.7/runtime.yaml

Deploy function

tm deploy service python-test -f https://github.com/serverless/examples \
                              --build-template knative-python37-runtime \
                              --build-argument DIRECTORY=aws-python-simple-http-endpoint \
                              --build-argument HANDLER=handler.endpoint \
                              --wait

Execute function via public URL

curl python-test.default.dev.triggermesh.io

{"statusCode": 200, "body": "{\"message\": \"Hello, the current time is 06:45:49.174383\"}"}

To use Python 2.7 runtime simply replace version tag in step 1 and 2 with python-2.7 and knative-python27-runtime accordingly.

Nodejs

Install node 4.3 runtime

tm deploy task -f https://raw.githubusercontent.com/triggermesh/knative-lambda-runtime/master/node-4.x/runtime.yaml

Deploy example function

tm deploy service node4-test -f https://github.com/serverless/examples \
                             --build-template knative-node4-runtime \
                             --build-argument DIRECTORY=aws-node-serve-dynamic-html-via-http-endpoint \
                             --build-argument HANDLER=handler.landingPage \
                             --wait

Function is ready

curl http://node43-test.default.dev.triggermesh.io

{"statusCode":200,"headers":{"Content-Type":"text/html"},"body":"\n  <html>\n    <style>\n      h1 { color: #73757d; }\n    </style>\n    <body>\n      <h1>Landing Page</h1>\n      <p>Hey Unknown!</p>\n    </body>\n  </html>"}

Node 10 with `async` handler

Prepare function code

mkdir example-lambda-nodejs
cd example-lambda-nodejs
cat > handler.js <<EOF
async function justWait() {
  return new Promise((resolve, reject) => setTimeout(resolve, 100));
}

module.exports.sayHelloAsync = async (event) => {
  await justWait();
  return {hello: event && event.name || "Missing a name property in the event's JSON body"};
};
EOF

node -e "require('./handler').sayHelloAsync({}).then(h => console.log(h))"

Install node-10.x runtime

tm deploy task -f https://raw.githubusercontent.com/triggermesh/knative-lambda-runtime/master/node-10.x/runtime.yaml

Deploy function

tm deploy service node-lambda -f . --build-template knative-node10-runtime \
                                   --build-argument HANDLER=handler.sayHelloAsync \
                                   --wait

Done:

curl http://node-lambda.default.dev.triggermesh.io --data '{"name": "Foo"}'
# {"hello":"Foo"}

Go

Prepare function code

You will create a main.go file in the example-lambda-go directory.

Create the directory and get into it:

mkdir example-lambda-go
cd example-lambda-go

Copy and Paste the following into a main.go file:

package main

import (
        "fmt"
        "context"
        "github.com/aws/aws-lambda-go/lambda"
)

type MyEvent struct {
        Name string `json:"name"`
}

func HandleRequest(ctx context.Context, name MyEvent) (string, error) {
        return fmt.Sprintf("Hello %s!", name.Name ), nil
}

func main() {
        lambda.Start(HandleRequest)
}

Install Go runtime

tm deploy task -f https://raw.githubusercontent.com/triggermesh/knative-lambda-runtime/master/go-1.x/runtime.yaml

Deploy function

tm deploy service go-lambda -f . --build-template knative-go-runtime --wait

Done:

curl http://go-lambda.default.dev.triggermesh.io --data '{"Name": "Foo"}'
"Hello Foo!"

Dependecies

To have more control over the go project dependecies, KLR runtime will read and "ensure" Gopkg.toml file if it's available in the project's root. Without toml file, only go get will be executed before build. If the project has dependencies stored in a private repository, you can create k8s secret with SSH key that will be used for git clone operation:

cat ~/.ssh/id_rsa | tm set git-auth

where ~/.ssh/id_rsa is a path to SSH private key associated with your git account

Ruby

Install Ruby 2.5 runtime

tm deploy task -f https://raw.githubusercontent.com/triggermesh/knative-lambda-runtime/master/ruby-2.5/runtime.yaml

Deploy example function

tm deploy service ruby-lambda -f https://github.com/serverless/examples --build-argument DIRECTORY=aws-ruby-simple-http-endpoint --build-argument HANDLER=handler.endpoint --build-template knative-ruby25-runtime --wait

Function is ready

curl http://ruby-test-25.default.dev.triggermesh.io
{"statusCode":200,"body":"{\"date\":\"2019-01-14 19:10:29 +0000\"}"}

Support

We would love your feedback on this tool so don't hesitate to let us know what is wrong and how we could improve it, just file an issue

Code of Conduct

This plugin is by no means part of CNCF but we abide by its code of conduct

mparaz/knative-lambda-runtime