Haskell Webserver

haskell-webserver.hs

{-# LANGUAGE OverloadedStrings #-}
{- | Sample Haskell Web Application 
 -   Based on WAI, implemented with the WARP web server.
 -   See https://www.yesodweb.com/book/web-application-interface
 -   See https://www.stackage.org/package/wai
 -} 
import Network.Wai
import Network.Wai.Handler.Warp (run)
import Network.Wai.Middleware.RequestLogger
import Network.Wai.Application.Static

{- | Entry point of the application. Defines and logs on which 
 -   port to listen, and starts the web server. 
 -}
main :: IO ()
main = do
    -- Probably a good idea later on to read the port from input.
    let port = 8181 
    -- Determine the root folder of the website:
    -- if relative, starts at the webserver executable.
    let webroot = "public"
    putStrLn $ "Listening on port " ++ show port
    -- Choice 1: run over http, no encryption.
    run port $ logStdout $ staticApp $ defaultFileServerSettings webroot

Haskell WAI and WARP modules make creating static webservers very easy, as the above is all but a one-liner. That's it: that's the whole server. Useful for local development and testing.

Cabal file contents to get cabal to load program dependenciesL

cabal-version: >=1.10
-- Package description generated by 'cabal init'. For further documentation,
-- see http://haskell.org/cabal/users-guide/

name: webserver
version: 0.1.0.1
-- synopsis:
-- description:
-- bug-reports:
-- license:
license-file: LICENSE
author: A.E.Veltstra
maintainer: aev@sdf.org
copyright: CopyLeft
category: Web Applications
build-type: Simple
extra-source-files: README.md
, CHANGELOG.md

executable webserver
main-is: Main.hs
other-extensions: OverloadedStrings
build-depends: base >=4.16 && <4.17
, wai
, wai-app-static
, wai-extra
, wai-log
, warp
, warp-tls

-- hs-source-dirs:
default-language: Haskell2010