@startuml HTTP Binding

box Function Process in Local Environment or Container

control ENTRYPOINT

participant "~__main__" as Main

participant HTTPServer

participant Server [

Web Server

----

""Flask/Gunicorn""

]

participant Middleware

participant "User Function" as UserFunction

participant DaprClient

end box

entity "Dapr Sidecar " as DaprSidecar

== OpenFunction Serving ==

ENTRYPOINT -> Main ** : execute

note over ENTRYPOINT, Main: Pass through __CLI arguments__ and \ncontainer __environment variables__

Main -> Main : load user fnction file

note left: ""function (request) {}""

Main -> HTTPServer ** : create

note over Main, HTTPServer: Hand over __user function__, __function type__ \nand __context__ parsed from env variables

HTTPServer -> Server ** : new

note over Server: Depend on debug mode

HTTPServer -> Middleware ** : new

HTTPServer -> Server : use Middleware

note over HTTPServer, Server: Pass context to middleware

|||

HTTPServer -> Server : use others middlewares

|||

HTTPServer -> UserFunction ** : wrap user function

note over HTTPServer, UserFunction: Register as HTTP or CloudEvent Function

HTTPServer -> Server : bind wrapper to "/*" route

...

== OpenFunction Invocation ==

[-> Server ++ : HTTP request to "/"

Server -> UserFunction ++ : execute user function

UserFunction --> Server -- : return execution result "data"

alt ""runtime"" = ""knative"" and ""outputs"" is not empty

Server -> Middleware ++ : invoke Middleware

Middleware -> DaprClient ** : new

loop each OpenFunction Output

Middleware -> DaprClient ++ : send "data"

DaprClient -> DaprSidecar ++ : invoke binding or publication with "data"

DaprSidecar --> DaprClient -- : return result

DaprClient --> Middleware -- : forward result

end

Middleware --> Server -- : return "data" as response

end

[<- Server -- : send response

...

@enduml