I am working on Suave 1.0 + Angular 2.0 sample app and very interesting to start Suave server in watch mode, so the server watch file changes (js,css,html) in root folder and sub-folders and automatically send refresh command to all open browser tabs with my application when any file is changed.
lite-server from Angular 2 5min Quckstark can do this and it is very handy.
I think that most of watch pieces can be found in latest Steffen Forkmann's post but it is not very clean how to send refresh to the open browser tabs.
Please provide complete code of similar implementation with Suave.
The code of Suave server should looks similar to this
#r "packages/Suave/lib/net40/suave.dll"
#r "packages/FAKE/tools/FakeLib.dll"
open Fake
open Suave
open Suave.Operators
open Suave.Sockets.Control
open Suave.WebSocket
open Suave.Utils
open Suave.Files
open Suave.RequestErrors
open Suave.Filters
open System
open System.Net
let port =
let rec findPort port =
let portIsTaken =
System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().GetActiveTcpListeners()
|> Seq.exists (fun x -> x.Port = int(port))
if portIsTaken then findPort (port + 1us) else port
findPort 8083us
let logger = Logging.Loggers.ConsoleWindowLogger Logging.LogLevel.Verbose
let refreshEvent = new Event<_>()
let handleWatcherEvents (events:FileChange seq) =
for e in events do
let fi = fileInfo e.FullPath
traceImportant <| sprintf "%s was changed." fi.Name
refreshEvent.Trigger()
let socketHandler (webSocket : WebSocket) =
fun cx -> socket {
while true do
let! refreshed =
Control.Async.AwaitEvent(refreshEvent.Publish)
|> Suave.Sockets.SocketOp.ofAsync
do! webSocket.send Text (ASCII.bytes "refreshed") true
}
let cfg =
{ defaultConfig with
homeFolder = Some (__SOURCE_DIRECTORY__)
bindings =
[ HttpBinding.mk HTTP IPAddress.Loopback port ]
listenTimeout = TimeSpan.FromMilliseconds 3000. }
let app : WebPart =
choose [
Filters.log logger logFormat >=> never
Filters.path "/websocket" >=> handShake socketHandler
Filters.GET >=> Filters.path "/" >=> file "index.html"
Writers.setHeader "Cache-Control" "no-cache, no-store, must-revalidate"
>=> Writers.setHeader "Pragma" "no-cache"
>=> Writers.setHeader "Expires" "0"
>=> browseHome
NOT_FOUND "Found no handlers."
]
let watcher =
!! ("app/*.js")
++ ("*.html")
|> WatchChanges handleWatcherEvents
try
System.Diagnostics.Process.Start(sprintf "http://localhost:%d/index.html" port) |> ignore
startWebServer cfg app
finally
watcher.Dispose()
So we setup watcher that handle changes in js(generated by TypeScript) and html files and send refresh command to the client, but in the same time we need to add following code to the head section of index.html to handle refresh on the client side
<!-- 3. Listen on refresh events from the server -->
<script language="javascript" type="text/javascript">
function init()
{
websocket = new WebSocket("ws://"+window.location.host+"/websocket");
websocket.onmessage = function(evt) { location.reload(); };
}
window.addEventListener("load", init, false);
</script>
The full demo app you can find here
Related
I would like to upload files using Suave. I understand that small files will automatically get written to a /tmp folder, but my files are too large for that. What I would like to do is process them as a stream and send them to long term storage, via the Suave server.
Here is my server:
#r "nuget: Suave"
open System.IO
open Suave
open Suave.Sockets
open Suave.Sockets.Control
let config = defaultConfig
let socketTask (conn : Connection, httpResult : HttpResult) =
socket {
printfn "Started socket task"
use stream = new TransportStream (conn.transport)
use reader = new StreamReader (stream)
while not reader.EndOfStream do
printfn "Reading... "
let! line = SocketOp.ofAsync (async {
let! line = reader.ReadLineAsync ()
return line
})
printfn "%s" line
printfn "Finished socket task"
return conn
}
let app : WebPart =
(fun ctx -> async {
printfn "Received request"
return
Some
{
ctx with
response =
{
ctx.response with
content = SocketTask socketTask
}
}
})
startWebServer config app
But when I run this curl command, it just hangs:
$ curl -X POST --data-binary #big-file.csv localhost:8080
$ dotnet fsi ./Suave.fsx
[17:32:05 INF] Smooth! Suave listener started in 14.279ms with binding 127.0.0.1:8080
Received request
Started socket task
I would expect the uploaded file to be printed line-by-line.
What am I missing here?
I would like to create a WebPart that forwards all requests to another web server that I specify.
Usage might look like this:
let app =
choose
[
path "/" >=> OK "Hello, world. "
path "/graphql" >=> createProxy "localhost:5000"
RequestErrors.NOT_FOUND "Not found"
]
startWebServer defaultConfig app
How should I implement this in Suave?
I found this snippet, but it seems to be for an old version of Suave:
let build_proxy_resolver (fwd_to_host : String) fwd_to_port =
let heserver = System.Net.Dns.GetHostEntry(fwd_to_host)
let ipaddr = heserver.AddressList.[0]
fun (request : HttpRequest) ->
Some (ipaddr, fwd_to_port)
let build_headers ctx =
//add and remove headers from the ctx, return the header list
ctx.request.headers
let proxy_app (ctx:HttpContext) =
let new_headers = build_headers ctx
let fwd_ctx = {ctx with request={ctx.request with headers=new_headers}}
let pxy = proxy (build_proxy_resolver "PROXY_TO.com" 80us) fwd_ctx
{ctx with response = { ctx.response with status=Suave.Types.Codes.HTTP_200; content=SocketTask pxy }} |> Some
This has now been added to Suave:
open System
open Suave
open Suave.Proxy
let app =
choose
[
path "/" >=> OK "Hello, world. "
path "/graphql" >=> proxy (Uri "http://localhost:5000")
RequestErrors.NOT_FOUND "Not found"
]
startWebServer defaultConfig app
module Main
open System
open System.Threading
open System.Threading.Tasks
open NetMQ
open NetMQ.Sockets
let uri = "ipc://hello-world"
let f (token : CancellationToken) =
use server = new ResponseSocket()
use poller = new NetMQPoller()
poller.Add(server)
printfn "Server is binding to: %s" uri
server.Bind(uri)
printfn <| "Done binding."
use __ = server.ReceiveReady.Subscribe(fun x ->
if token.CanBeCanceled then poller.Stop()
)
use __ = server.SendReady.Subscribe(fun x ->
if token.CanBeCanceled then poller.Stop()
)
poller.Run()
printfn "Server closing."
server.Unbind(uri)
let src = new CancellationTokenSource()
let token = src.Token
let task = Task.Run((fun () -> f token), token)
src.CancelAfter(100)
task.Wait() // Does not trigger.
My failed attempt looks something like this. The problem is that the poller will only check the cancellation token if it gets or sends a message. I guess one way to do it would be to send a special cancel message from the client rather than these tokens, but that would not work if the server gets into a send state.
What would be a reliable way of closing the server in NetMQ?
I have an existing owin application written in C# and would like to mount a suave application as a middleware but since I am relatively new to F# I am finding it quite difficult to navigate how this should be done. I think I'm looking for something like:
// in F# land
module MySuaveApp.ApiModule
let app =
choose
[ GET >=> choose
[ path "/hello" >=> OK "Hello GET"
path "/goodbye" >=> OK "Good bye GET" ]
POST >=> choose
[ path "/hello" >=> OK "Hello POST"
path "/goodbye" >=> OK "Good bye POST" ] ]
let getSuaveAsMiddleware() =
... magic goes here ...
// in Startup.cs
app.Use(MySuaveApp.ApiModule.getSuaveAsMiddleware())
As for what that magic should be I think it's a combination of OwinApp.ofAppFunc or OwinApp.ofMidFunc, but I can't for the life of me figure out what it should be.
There is no easy magic.1 ofAppFunc and ofMidFunc are here for creating WebParts out of OWIN components, i.e. OWIN -> Suave, whereas you want Suave -> OWIN.
The following works for your 'application' and serves as an example what would be needed to get it working:
open System.Runtime.CompilerServices
[<Extension>]
module Api =
open Suave
open Successful
open Filters
open Operators
open Microsoft.Owin
open System.Threading.Tasks
let app =
choose [ GET >=> choose [ path "/hello" >=> OK "Hello GET"
path "/goodbye" >=> OK "Good bye GET" ]
POST >=> choose [ path "/hello" >=> OK "Hello POST"
path "/goodbye" >=> OK "Good bye POST" ] ]
let withCtx (ctx : IOwinContext) webpart =
async {
let request =
{ HttpRequest.empty with
headers = ctx.Request.Headers |> List.ofSeq |> List.map (fun kvp -> kvp.Key, kvp.Value |> String.concat ",")
host = ctx.Request.Host.Value
``method`` = HttpMethod.parse ctx.Request.Method
url = ctx.Request.Uri }
let! res = webpart { HttpContext.empty with request = request }
res |> Option.iter (fun r ->
ctx.Response.StatusCode <- r.response.status.code
match r.response.content with
| Bytes bs -> ctx.Response.Write bs
| _ -> failwith "Not supported")
return res
}
type SuaveMiddleware(n) =
inherit OwinMiddleware(n)
override __.Invoke(context : IOwinContext) =
let res = withCtx context app |> Async.RunSynchronously
match res with
| Some _ -> Task.CompletedTask
| None -> base.Next.Invoke context
[<Extension>]
let UseSuave(app : Owin.IAppBuilder) =
app.Use(typeof<SuaveMiddleware>)
The main works is delegated to withCtx that tries to fulfill a request given a IOwinContext and a WebPart. It does so mainly by converting back and forth between Suave and OWIN context and related entities.
Note that this code is a PoC (Proof-of-Concept) and not fit for production.
The SuaveMiddleware forwards request to the next middleware if Suave cannot fulfill the request.
Using from C# is easy then:
using MySuave;
using Owin;
namespace Main
{
using System.Web.Http;
public class Startup
{
public static void Configuration(IAppBuilder appBuilder)
{
appBuilder.UseSuave();
var config = new HttpConfiguration();
config.MapHttpAttributeRoutes();
appBuilder.UseWebApi(config);
}
}
}
given
namespace Main.Example
{
using System.Web.Http;
[RoutePrefix("api")]
public class ExampleController : ApiController
{
[HttpGet, Route("")]
public string Index()
{
return "Hello World";
}
}
}
And both URLs work:
http://localhost:9000/hello
Hello GET
http://localhost:9000/api
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/">Hello World</string>
1 At least none I know of. I'm happy to be proven wrong.
EDIT for moderators
I had this issue this morning, but the problem has been somehow solved on its own. If it were to come back and I could exactly tell what is happening I would reopen another question with more details.
Thx
I have the following code to start a http listener (I have so far copied and pasted a lot from this series of article )
httpAgent.fs :
namespace Server.Core
open System.Net
open System.Threading
type Agent<'T> = MailboxProcessor<'T>
/// HttpAgent that listens for HTTP requests and handles
/// them using the function provided to the Start method
type HttpAgent private (url, f) as this =
let tokenSource = new CancellationTokenSource()
let agent = Agent.Start((fun _ -> f this), tokenSource.Token)
let server = async {
use listener = new HttpListener()
listener.Prefixes.Add(url)
listener.Start()
while true do
let! context = listener.AsyncGetContext()
agent.Post(context) }
do Async.Start(server, cancellationToken = tokenSource.Token)
/// Asynchronously waits for the next incomming HTTP request
/// The method should only be used from the body of the agent
member x.Receive(?timeout) = agent.Receive(?timeout = timeout)
/// Stops the HTTP server and releases the TCP connection
member x.Stop() = tokenSource.Cancel()
/// Starts new HTTP server on the specified URL. The specified
/// function represents computation running inside the agent.
static member Start(url, f) =
new HttpAgent(url, f)
httpServer.fs :
module httpServer
open Server.Core
let execute = fun ( server : HttpAgent) -> async {
while true do
let! ctx = server.Receive()
ctx.Response.Reply(ctx.Request.InputString) }
This code runs well in a console project (ie: I can access it with a browser, it does find it) :
[<EntryPoint>]
let main argv =
let siteRoot = #"D:\Projects\flaming-octo-spice\src\Site"
let url = "http://localhost:8082/"
let server = HttpAgent.Start(url, httpServer.execute)
printfn "%A" argv
let s = Console.ReadLine()
// Stop the HTTP server and release the port 8082
server.Stop()
0 // return an integer exit code
whereas in my test, I cannot access the server. I have even put some breakpoint in order to check with my browser if the server was up and running , but chrome tells me no host exists with ths url.
namespace UnitTestProject1
open System
open Microsoft.VisualStudio.TestTools.UnitTesting
open Server.Core
open System.Net.Http
[<TestClass>]
type HttpServerTests() =
[<TestMethod>]
member x.Should_start_a_web_site_with_host_address () =
let host = "http://localhost:8082/"
let server = HttpAgent.Start(host, httpServer.execute)
let url = "http://localhost:8082/test/url"
let client = new HttpClient()
let response = client.GetAsync(url)
Assert.IsTrue(response.Result.IsSuccessStatusCode )
Thanks for any enlightment...
You're starting server at port 8092, but client tries to access it at 8082.