"Access to the path 'C:\\home\\site\\wwwroot\\dataModel.csv' is denied." in a .NET Core app, deployed in Azure - azure

Question

I have an ASP.NET Core API app which runs some background processes via HangFire. One of the process includes
writing a csv file onto the wwwroot folder as following:
public async Task Work(PerformContext context)
{
var latestLikes = await this.likeRepository
.All()
.Select(l => new LatestLikesServiceModel
{
UserId = l.UserId,
BeatId = l.BeatId,
})
.ToListAsync();
var modelPath = this.webHostEnvironment.ContentRootPath + "\\dataModel.csv";
using (var writer = new StreamWriter(modelPath))
using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csv.WriteRecords(latestLikes);
}
}
In localhost it works perfectly, but when I deploy it in azure the HangFire log returns:
"System.UnauthorizedAccessException","ExceptionMessage":"Access to the path 'C:\home\site\wwwroot\dataModel.csv' is denied."
How can I resolve this issue?

Answer 1

After one week of researching I finally found out the solution
I should have mentioned that I use Azure DevOps for CI & CD.
By default the azure app service is deployed as a zip (which cuts the direct access to the file system) What I had to do was to change the Deployment method to a Web Deploy (Additional Deployment Options) and I finally have access to the file system.
For more descriptive information, please refer:
https://tomasherceg.com/blog/post/azure-app-service-cannot-create-directories-and-write-to-filesystem-when-deployed-using-azure-devops#comments

Answer 2

Below code works fine on my side:
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
namespace FunctionApp97
{
public static class Function1
{
[FunctionName("Function1")]
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
ExecutionContext ec,
ILogger log)
{
string str = ec.FunctionAppDirectory;
log.LogInformation(str);
using (var reader = new StreamReader(str+ #"\filename.txt"))
{
string line;
while ((line = reader.ReadLine()) != null)
{
log.LogInformation(line);
}
}
return new OkObjectResult(str);
}
}
}