Thanks Michele for the clarification My knative remark was only about to scale to zero, meaning when there is times that no one is using my app no pod/container is running at all.
The main.go code can still be loaded via ConfigMap in Knative or without in Kubernetes. It still uses the same image - Carlos Santana @csantanapr > On Jan 21, 2019, at 1:34 PM, Michele Sciabarra <[email protected]> wrote: > > Actually YES this is exactly what I did. A websocket that accept a websocket > and writes in kafka. > > There is not yet a demo, but I am working on it. I am building a small > webchat doing it. > > So far the demo is only this one https://hellows.sciabarra.net/ that uses the > "hello.go" as an action turned in a websocket. > > If you use a websocket client you can see it is actually the action aswering > in a websocket. > >> ws wss://hellows.sciabarra.net/hello >> {"name":"Mike"} > < {"golang-main-single":"Hello, Mike!"} > >> {} > < {"golang-main-single":"Hello, world!"} > > You just need the action loop container modified and you can deploy an action > in Kubernetes > > Yes this can be hooked in knative, but I did it simpler with an "autoinit". > Code of the action is provided in a file through a configmap and then the > runtime initialize the action instead of waiting a /init and serves it in a > websocket. > > The deployment of the "https://hellows.sciabarra.net"; is entirely here: > > https://github.com/sciabarracom/incubator-openwhisk-runtime-go/blob/websocket-support/examples/websocket-hello/hellows.yml > > The client is just a static html page. > > I can talk of this work wednesday if we can consider merging this feature. > > -- > Michele Sciabarra > [email protected] > > ----- Original message ----- > From: Carlos Santana <[email protected]> > To: [email protected] > Subject: Re: [Long] I implemented websocket support for the Golang and > related runtimes: > Date: Mon, 21 Jan 2019 12:37:05 -0500 > > Hi Michele this looks very cool in deed > > Where you able to create a container in k8s with a main.go that took > websocket input and output to a persistent kafka connection > > I'm interested in this as I have a use case that I want IBM Cloud Function > to ingest into kafka, and I was going to build similar thing as you did > using http 1or 2 server, that then ingest into kafka as a service (Event > Streams). > I was going to deploy this container into kubernetes, but I wanted the > container to scale down to zero using Knative. > > You have such main.go for your runtime with websocket at one side and kafka > producer at the other? > > -- Carlos > > On Thu, Jan 17, 2019 at 1:07 PM Michele Sciabarra <[email protected]> > wrote: > >> Hello whiskers! >> >> Sorry it is a bit long, so I split it into parts with headlines. >> >> TL;DR >> >> I implemented support for Websocket so you can deploy an Action as a >> WebSocket server if you have a Kubernetes cluster (or just a Docker >> server). See at the end of this post for an example of a Kubernetes >> deployment descriptor. >> >> Here is a very simple demo using it: >> >> https://hellows.sciabarra.net/ >> >> It uses a websocket server implemented using the golang runtime and the >> code of an UNCHANGED OpenWhisk action. All the magic happens at deployment >> using the descriptor provided. >> >> I believe it is a good foundation for implementing websocket support in >> OpenWhisk. The next step would be to provide support at the API level. >> >> After reading the rest, the question is: does the community approve this >> feature? If yes, I can submit a PR for including it in the next release of >> the actionloop. >> >> 1. Motivation: why I did this >> >> A few days ago I asked what was the problem in having an action that >> creates a persistent connection to Kafka. I was answered that a Serverless >> environment can flood Kafka with requests because more actions are spawn >> when the load increase. >> >> The solution is to create a separate server to be deployed somewhere, for >> example, Kubernetes, maybe using WebSockets to communicate with Kafka. In >> short, I had the need to transform an action in a WebSocket server. >> >> Hence I had the idea of adding WebSocket support to Action as WebSocket >> server, adding support for WebSocket to ActionLoop, so I could create a >> WebSocket server in the same way as you write an action. >> >> 2. What I did >> >> I implemented WebSocket support in the action runtime. If you deploy the >> action now it answers not only to `/run` but also to `/ws` (it is >> configurable) as a WebSocket in continuous mode. >> >> You enable the WebSocket setting the environment variable OW_WEBSOCKET. >> Also, for the sake of easy deployment, there is also now an autoinit >> feature. If you set the environment variable to OW_AUTOINIT, it will >> initialize the runtime from the file you specified in the variable. >> >> Ok, fine you can say, but how can I use it? >> >> With a Kubernetes descriptor! You can launch the runtime in Kubernetes, >> provide the main action in it (you can also download it from a git repo or >> store in a volume), and now your action is a web socket server answering to >> your requests. >> >> Look to the following descriptor for an example: >> >> It is a bit long, this is what it does >> >> - it creates a configmap containing the action code >> - it launches the image mounting the action code >> - the image initialize the action and then listen to the WebSocket >> - the image also exposes the web socket using an ingress >> >> >> apiVersion: v1 >> kind: Namespace >> metadata: >> name: hellows >> --- >> apiVersion: v1 >> kind: ConfigMap >> metadata: >> name: hellows >> namespace: hellows >> data: >> main.go: | >> package main >> import "fmt" >> func Main(obj map[string]interface{}) map[string]interface{} { >> name, ok := obj["name"].(string) >> if !ok { >> name = "world" >> } >> fmt.Printf("name=%s\n", name) >> msg := make(map[string]interface{}) >> msg["golang-main-single"] = "Hello, " + name + "!" >> return msg >> } >> --- >> apiVersion: v1 >> kind: Pod >> metadata: >> name: hellows >> namespace: hellows >> labels: >> app: hellows >> spec: >> volumes: >> - name: mnt >> configMap: >> name: hellows >> containers: >> - name: hellows >> image: actionloop/golang-v1.11:ws3 >> ports: >> - containerPort: 8080 >> protocol: TCP >> volumeMounts: >> - name: mnt >> mountPath: "/mnt" >> env: >> - name: OW_WEBSOCKET >> value: /hello >> - name: OW_AUTOINIT >> value: /mnt/main.go >> --- >> apiVersion: v1 >> kind: Service >> metadata: >> name: hellows >> namespace: hellows >> spec: >> ports: >> - port: 8080 >> protocol: TCP >> targetPort: 8080 >> selector: >> app: hellows >> --- >> apiVersion: extensions/v1beta1 >> kind: Ingress >> metadata: >> name: hellows >> namespace: hellows >> spec: >> rules: >> - host: hellows.sciabarra.net >> http: >> paths: >> - path: /hello >> backend: >> serviceName: hellows >> servicePort: 8080 >> >> >> -- >> Michele Sciabarra >> [email protected] >> > > > -- > Carlos Santana > <[email protected]>
