Permission denied when writing to a folder after deploying to linux server

Question

User-1820491116 posted

Hi,

i have been getting Permission denied IOexception after deploying a .net core 5 project to a linux ubuntu 20.04, this happens when i try to write to any folder inside my application like for an example changing profile picture .

i've tried the following command to change the permissions of the folder "ProfilePictures" but it is not working 

chmod -R 0755 /var/www/elseforty.com/publish/wwwroot/Uploads/ProfilePictures/

here is the full exception message

IOException: Permission denied

Show raw exception details
UnauthorizedAccessException: Access to the path '/var/www/elseforty.com/publish/wwwroot/Uploads/ProfilePictures/_de55.jpg' is denied.
Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, string path, bool isDirectory, Func<ErrorInfo, ErrorInfo> errorRewriter)
Microsoft.Win32.SafeHandles.SafeFileHandle.Open(string path, OpenFlags flags, int mode)
System.IO.FileStream.OpenHandle(FileMode mode, FileShare share, FileOptions options)
System.IO.FileStream..ctor(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, FileOptions options)
System.IO.FileStream..ctor(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize)
System.IO.File.Create(string path)
ElseForty.FileServices.Files+Server.UploadFileAsync(IFormFile file, string fullFolderPath) in Files.cs
ElseForty.Controllers.AccountController.EditProfile(User_EditProfileViewModel model) in AccountController.cs
Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor+TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, object controller, object[] arguments)
System.Threading.Tasks.ValueTask<TResult>.get_Result()
System.Runtime.CompilerServices.ValueTaskAwaiter<TResult>.GetResult()
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask<IActionResult> actionResultValueTask)
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

any help is appreciated

Answer 1

User-474980206 posted

Only the folder owner has write access to files or folder. Use ls -l to get the owners name of the files and folder. Then use ps -u to what user your asp.net process is running under.

Answer 2

User-1820491116 posted

Hi bruce, 

the folders are owner by the 'root' user, the ps -u is returning this, i don't know what can i do with this

root@localhost:~# ps -u 
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root        1342  0.0  0.0   7352  1932 ttyS0    Ss+  May06   0:00 /sbin/agetty 
root        1344  0.0  0.0   5828  1524 tty1     Ss+  May06   0:00 /sbin/agetty 
root      138589  0.0  0.2   8308  4960 pts/0    Ss   01:29   0:00 -bash
root      142620  0.0  0.1   8892  3196 pts/0    R+   02:12   0:00 ps -u

i've managed to set the folder permission manually from filezila, it works as expected

folder=>(right click)File Attributes

but i want to do it automatically since i'm creating and deleting folders on my server from my admin pannel

i tried also this solution but it is not working as well

            public static bool Exec(string filePath, string permissions = "700", bool recursive = false)
            {
                string cmd;
                if (recursive)
                    cmd = $"chmod -R {permissions} {filePath}";
                else
                    cmd = $"chmod {permissions} {filePath}";

                try
                {
                    using (Process proc = Process.Start("/bin/bash", $"-c \"{cmd}\""))
                    {
                        proc.WaitForExit();
                        return proc.ExitCode == 0;
                    }
                }
                catch
                {
                    return false;
                }
            }

 Files.Server.Exec("/var/www/elseforty.com/wwwroot/Uploads/ProfilePictures", "757", true); 

any help is welcome

Answer 3

User-1820491116 posted

i've managed to find a solution for this, 

you don't need to break your head with code that will change folders permissions , all you have to do is to set the parent folder permissions manually with recursive being set to true, this will automatically grant the parent folder permissions to the children folders 

for an example i have a structure like this /MyProject/wwwroot/Uploads/{my dynamically created folders here}

all i did is set Read, Write, Execute permissions on the folder {Uploads} using the command bellow

chmod -R 757 /var/www/elseforty.com/wwwroot/Uploads