Awesome
F#chat
Sample chat application built with netcore, F#, Akka.net and Fable.
Requirements
- dotnet SDK 2.0.0 or higher
- node.js 4.8.2 or higher
- yarn (
npm i yarn -g) - npm5: JS package manager
Building and running the app
- Install JS dependencies:
yarn - Move to
src/Clientfolder:cd src\Client - Install F# dependencies:
dotnet restore - Build client bundle:
dotnet fable webpack -p - Move to
src/Serverfolder:cd ..\Server - Install F# dependencies:
dotnet restore - Run the server:
dotnet run - Head your browser to
http://localhost:8083/
Developing the app
- Start the server (see instruction above)
- Move to
src/Clientfolder:cd src\Client - Start Fable daemon and Webpack dev server:
dotnet fable webpack-dev-server - In your browser, open: http://localhost:8080/
- Enjoy HMR (hotload module reload) experience
Running integration (e2e) tests
- Start the server
- Move to
test/e2efolder:cd test\e2e - run the tests:
dotnet run
Implementation overview
Authentication
FsChat supports both permanent users, authorized via goodle or github account, and anonymous ones, those who provide only nickname.
In order to support the google/fb authentication scenario, fill in the client/secret in the CHAT_DATA/suave.oauth.config file. In case you do not see this file, run the server once and the file will be created automatically.
Akka streams
FsChat backend is based on Akka.Streams. The entry point is a ChannelFlow module which implements the channel actor, the flow for user participating in particular channel, and the flow for all channels the user is participating in.
UserSessionFlow brings everything together and implements the flow for the user browser session.
ChatServer is an actor which purpose is to keep the channel list. It's responsible for creating/dropping the channels.
UserStore is an actor which purpose is to know all users logged in. It supposed to be made persistent but it does not work for some reason (I created issue).
SocketFlow implements a flow decorating the server-side web socket.
Akkling
Akkling is a great tool for F# developers. It does not support netcore yet so I hacked it in my own clone and I store hacked packages in the chat repository.
Fable, Elmish
Client is written on F# with the help of Fable and Elmish (library?, framework?). Fable is great, Elmish is great.
Communication protocol
After client is authenticated all communication between client and server is carried via WebSockets. The protocol is defined in src/Shared/ChatProtocol.fs file which is shared between client and server projects.