EventsGateway

EventsGateway.fs

namespace Dodo.EventStream

open System
open System.IO
open System.Threading.Tasks
open Microsoft.Azure.WebJobs
open Microsoft.Azure.WebJobs.Extensions.Http
open Microsoft.AspNetCore.Http
open Microsoft.Extensions.Logging
open System.Text.Json
open System.Text

module EventsGateway =
    [<FunctionName("events")>]
    let run ([<HttpTrigger(AuthorizationLevel.Function, "post", Route = null)>] req: HttpRequest, log: ILogger):
        [<EventHub("outputEventHubMessage", Connection = "EventHubConnectionAppSetting")>] Task<string> =
        async {
            let! document = JsonDocument.ParseAsync req.Body |> Async.AwaitTask
            if log.IsEnabled LogLevel.Trace then log.LogTrace("Request body: {0}", document)
            let output = new MemoryStream()
            let writer = new Utf8JsonWriter(output)
            writer.WriteStartObject()
            writer.WriteString("Timestamp", DateTime.UtcNow.ToString("O"))
            writer.WriteStartObject("Event")
            for property in document.RootElement.EnumerateObject() do
                property.WriteTo(writer)
            writer.WriteEndObject()
            writer.WriteEndObject()
            writer.Flush()
            if log.IsEnabled LogLevel.Trace then
                log.LogTrace("Response body: {0}", Encoding.UTF8.GetString(output.ToArray()))
            return Encoding.UTF8.GetString(output.ToArray())
        }
        |> Async.StartAsTask