fsharp-azure-function.fsx

#r "System.Net.Http"
#r "Newtonsoft.Json"
#r "FSharp.Data"

open System
open FSharp.Data
open FSharp.Data.JsonExtensions
open System.Net
open System.Net.Http
open Newtonsoft.Json 

let Run(req: HttpRequestMessage, log: TraceWriter) =
    async {
        log.Info(sprintf 
            "Hello from F# function on Azure!")
        
        let storageAccountName = "<name-of-your-storage-account>"
        let pathToFileInStorage = "test/text.txt"
        let resourceUrl = "https://storage.azure.com/"
        
        // Set name to query string
        let name =
            req.GetQueryNameValuePairs()
            |> Seq.tryFind (fun q -> q.Key = "name")

        let accessTokenRequest = 
           Http.RequestString(
               Environment.GetEnvironmentVariable("MSI_ENDPOINT"), 
               headers = [ "secret", Environment.GetEnvironmentVariable("MSI_SECRET") ], 
               httpMethod="GET", 
               query = ["api-version", "2017-09-01"; "resource", resourceUrl ])
          |> JsonValue.Parse

        let accessToken = accessTokenRequest?access_token.AsString()
        log.Info(sprintf "Access Token: " + accessToken)

        let fileContent = 
           Http.RequestString(
               ("https://" + storageAccountName + ".blob.core.windows.net/" + pathToFileInStorage), 
               headers = [ "Authorization", ("Bearer " +  accessToken); "x-ms-version", "2017-11-09" ], 
               httpMethod="GET")

        log.Info(sprintf "File Content: " + fileContent)
                
        match name with
        | Some x ->
            return req.CreateResponse(HttpStatusCode.OK, "Hello " + x.Value + "! File Content: '" + fileContent + "'")
        | None ->
            return req.CreateResponse(HttpStatusCode.OK, "File content: '" + fileContent + "'")
    } |> Async.RunSynchronously