ASPNETCORE_CONTENTROOT being ignored in .NET 7

[bfren]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

ASP.NET 7 is using the current working directory as content root - even if an override environment variable is set.

This is a problem using the S6 supervisor, where the current working directory is an S6 directory, not the directory containing the published files.

In ASP.NET 6, setting ASPNETCORE_CONTENTROOT forced the framework to look in the correct place - this appears to have stopped working with the release of .NET 7.

So, e.g. in printenv:

# printenv
DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false
HOSTNAME=eb3218af2e48
SHLVL=1
HOME=/root
DOTNET_RUNNING_IN_CONTAINER=true
S6_CMD_WAIT_FOR_SERVICES_MAXTIME=0
ASPNET_VERSION_MINOR=7.0
TERM=xterm
ASPNET_ASSEMBLY=xxxxxx.dll
ASPNETCORE_CONTENTROOT=/app/live      <-- correct value
ASPNETCORE_URLS=http://+:5000
PWD=/

But in startup logs:

[16:14:51 INF] Content root path: /run/s6-rc:s6-rc-init:amgdpf/servicedirs/aspnet

And then requesting https://xxxxxx/css/bundles/1.0/licence.min.css gives this in the log:

[17:42:55 INF] Request finished HTTP/1.0 GET /css/bundles/1.0/licence.min.css - - - 404 0 - 0.2135ms

Despite:

# ls /app/live/wwwroot/css/bundles/1.0
licence.css      licence.min.css

Expected Behavior

Setting ASPNETCORE_CONTENTROOT should override the current working directory.

Steps To Reproduce

Execute:

docker run --rm -it
  -p 8000:80 \
  -v /path/to/app:/app \
  -e ASPNETCORE_CONTENTROOT=/tmp \
  mcr.microsoft.com/dotnet/aspnet:7.0 \
  sh

Inside the container execute dotnet /path/to/app/dll.

Content root is set to /app instead of /tmp (incorrectly).

Exceptions (if any)

No response

.NET Version

7.0.0

Anything else?

dotnet --list-runtimes
Microsoft.AspNetCore.App 7.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 7.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

[Tratcher]

Try DOTNET_CONTENTROOT

What does your Program.Main code look like?

[bfren]

That's done it! Thanks @Tratcher - so either the docs / breaking change stuff needs updating, e.g. here, or previous behaviour restored.

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.Run()

My understanding is that WebApplication.CreateBuilder() adds environment variables etc.

[bfren]

Also, in trying to work out what was going on, I tried setting it via the command line (--contentRoot), and it was still being set to the current working directory.

[halter73]

Thanks for the bug report. This does appear to be a regression which should be fixed in servicing. I think the fix belongs in HostApplicationBuilder which is in the dotnet/runtime repo.

Internally, the CWD overrides the content root set via ASPNETCORE_CONTENTROOT which WebApplicationBuilder passes to its HostApplicationBuilder via HostApplicationBuilderSettings.Configuration. HostApplicationBuilder is designed to override this configuration with higher priority configuration sources it configures by default (namely DOTNET_ prefixed environment variables and command-line arguments), but it shouldn't be overriding explicit content root configuration with the CWD default.

Also, in trying to work out what was going on, I tried setting it via the command line (--contentRoot), and it was still being set to the current working directory.

I'm not able to reproduce this part:

# ASPNETCORE_ENVIRONMENT=fun ASPNETCORE_CONTENTROOT=/tmp bin/Debug/net7.0/empty-web
/app
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://[::]:80
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: fun
info: Microsoft.Hosting.Lifetime[0]
      Content root path: /app
^Cinfo: Microsoft.Hosting.Lifetime[0]
      Application is shutting down...
# ASPNETCORE_ENVIRONMENT=fun bin/Debug/net7.0/empty-web --contentRoot /tmp
/tmp
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://[::]:80
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: fun
info: Microsoft.Hosting.Lifetime[0]
      Content root path: /tmp

ASPNET_-prefixed environment variables still work in general. There was a subtle intentional breaking change in .NET 7 to the priority these environment variables are given (see aspnet/Announcements#498), but this isn't the issue you're running into here.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

Tagging subscribers to this area: @dotnet/area-extensions-hosting
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

ASP.NET 7 is using the current working directory as content root - even if an override environment variable is set.

This is a problem using the S6 supervisor, where the current working directory is an S6 directory, not the directory containing the published files.

In ASP.NET 6, setting ASPNETCORE_CONTENTROOT forced the framework to look in the correct place - this appears to have stopped working with the release of .NET 7.

So, e.g. in printenv:

# printenv
DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false
HOSTNAME=eb3218af2e48
SHLVL=1
HOME=/root
DOTNET_RUNNING_IN_CONTAINER=true
S6_CMD_WAIT_FOR_SERVICES_MAXTIME=0
ASPNET_VERSION_MINOR=7.0
TERM=xterm
ASPNET_ASSEMBLY=xxxxxx.dll
ASPNETCORE_CONTENTROOT=/app/live      <-- correct value
ASPNETCORE_URLS=http://+:5000
PWD=/

But in startup logs:

[16:14:51 INF] Content root path: /run/s6-rc:s6-rc-init:amgdpf/servicedirs/aspnet

And then requesting https://xxxxxx/css/bundles/1.0/licence.min.css gives this in the log:

[17:42:55 INF] Request finished HTTP/1.0 GET /css/bundles/1.0/licence.min.css - - - 404 0 - 0.2135ms

Despite:

# ls /app/live/wwwroot/css/bundles/1.0
licence.css      licence.min.css

Expected Behavior

Setting ASPNETCORE_CONTENTROOT should override the current working directory.

Steps To Reproduce

Execute:

docker run --rm -it
  -p 8000:80 \
  -v /path/to/app:/app \
  -e ASPNETCORE_CONTENTROOT=/tmp \
  mcr.microsoft.com/dotnet/aspnet:7.0 \
  sh

Inside the container execute dotnet /path/to/app/dll.

Content root is set to /app instead of /tmp (incorrectly).

Exceptions (if any)

No response

.NET Version

7.0.0

Anything else?

dotnet --list-runtimes
Microsoft.AspNetCore.App 7.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 7.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Author:	bfren
Assignees:	halter73
Labels:	untriaged, area-Extensions-Hosting
Milestone:	-