Apache OpenServerless Streamer Examples

What is this

Sample repository on how to use Apache OpenServerless Streamer. The purpose is to show how stream from an OpenServerless action, avoiding the timeouts.

Small introduction

Apache OpenServerless Streamer is a unique solution: it can invoke an OpenServerless action or web action, returning a stream to the client.

How to use examples

Make a login on your OpenServerless account:

ops ide login <username> <host>

Then deploy as usual:

ops ide deploy

Three action are deployed:

Action	Web	Details
hello/call	True	This action will return 202 and call the hello/stream behind the scenes
hello/stream	False	Called by the hello/call action
hello/thread	True	This action will start the stream in a separate thread

With these three actions, a simple web page is deployed.

You can call the actions using the three buttons.

Examples

Action hello/call

This web action will call the hello/stream. We need to authenticate sending our wsk authorization token: this because hello/call needs to invoke a protected resource.

To test this action and see the streamed response, you can use this cURL:

curl -N -X POST "<streamer_url>/web/<user_namespace>/stream/call" \
  -H "Authorization: <auth_token>" \
  -H "Content-Type: application/json" \
  -d '{"input":"0123456789A0123456789B0123456789C0123456789D"}'

Note: you can retrieve auth_token from your ~/.wskprops file

Behind the scenes, the web action hello/call is called by the streamer, passing to it informations about the stream socket. The hello/call will then call the action hello/stream in non-blocking mode and returning http status 202 to the streamer.

Action hello/thread

This webaction is instead using a different technique. When called by the streamer, this action will create a thread to handle the socket and continue the stream. After creating the thread, the action is returning immediately sending a 202 http status.

To test this action and see the streamed response, you can use this cURL:

curl -N -X POST "<streamer_url>/web/<user_namespace>/stream/thread" \
  -H "Content-Type: application/json" \
  -d '{"input":"0123456789A0123456789B0123456789C0123456789D"}'

Final notes

Both action stream/thread and stream/stream actions need an higher timeout. OpenWhisk actions will last, by default, 60 seconds. To increase this timeout, we used this annotation: #--timeout 300000