The workshop instructions are written for .NET SDK 8.0.200+. 8.0.1xx users must use a slightly different pattern. The key differences are described in this document with the goal of making the workshop equally useful and straightforward to use.
dotnetapp is used as as the sample.
With 8.0.1xx, the Microsoft.NET.Build.Containers package must be added to publish an app,
$ dotnet --version
8.0.102
$ dotnet add package Microsoft.NET.Build.Containers
$ dotnet publish -t:PublishContainer
/home/rich/.nuget/packages/microsoft.net.build.containers/8.0.202/build/Microsoft.NET.Build.Containers.targets(194,5): warning : Microsoft.NET.Build.Containers NuGet package is explicitly referenced. Consider removing the package reference to Microsoft.NET.Build.Containers as it is now part of .NET SDK. [/home/rich/git/dotnet-docker/samples/dotnetapp/dotnetapp.csproj]
dotnetapp -> /home/rich/git/dotnet-docker/samples/dotnetapp/bin/Release/net8.0/publish/
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.
$ docker run --rm dotnetapp
42
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42 42 42
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a8" `Y42 a8" "8a 42 42P' `"8a a8P_____42 42
8b 42 8b d8 42 42 42 8PP!!!!!!! 42
"8a, ,d42 "8a, ,a8" 42, 42 42 "8b, ,aa 42,
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OSArchitecture: X64
OSDescription: Debian GNU/Linux 12 (bookworm)
FrameworkDescription: .NET 8.0.3
UserName: app
HostName : ce494dc0a437
ProcessorCount: 8
TotalAvailableMemoryBytes: 67382329344 (62.75 GiB)Tracking issue on warning: dotnet/sdk #39931.
With 8.0.2xx, the package does not need to be installed, but does require that EnableSdkContainerSupport is set.
$ dotnet --version
8.0.203
$ dotnet publish -t:PublishContainer -p:EnableSdkContainerSupport=true
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.
$ docker run --rm dotnetapp
42
42 ,d ,d
42 42 42
,adPPYb,42 ,adPPYba, MM42MMM 8b,dPPYba, ,adPPYba, MM42MMM
a8" `Y42 a8" "8a 42 42P' `"8a a8P_____42 42
8b 42 8b d8 42 42 42 8PP!!!!!!! 42
"8a, ,d42 "8a, ,a8" 42, 42 42 "8b, ,aa 42,
`"8bbdP"Y8 `"YbbdP"' "Y428 42 42 `"Ybbd8"' "Y428
OSArchitecture: X64
OSDescription: Debian GNU/Linux 12 (bookworm)
FrameworkDescription: .NET 8.0.3
UserName: app
HostName : 0b7e69a77d97
ProcessorCount: 8
TotalAvailableMemoryBytes: 67382329344 (62.75 GiB)There is no difference for ASP.NET Core apps. This pattern works for both SDK versions and produces the same results.
$ dotnet --version
8.0.102
$ dotnet publish -t:PublishContainer
MSBuild version 17.8.5+b5265ef37 for .NET
Determining projects to restore...
Restored /home/rich/git/dotnet-docker/samples/aspnetapp/aspnetapp/aspnetapp.csproj (in 125 ms).
aspnetapp -> /home/rich/git/dotnet-docker/samples/aspnetapp/aspnetapp/bin/Release/net8.0/aspnetapp.dll
aspnetapp -> /home/rich/git/dotnet-docker/samples/aspnetapp/aspnetapp/bin/Release/net8.0/publish/
Building image 'aspnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/aspnet:8.0'.
Pushed image 'aspnetapp:latest' to local registry via 'docker'..NET SDK 8.0.200 and the Microsoft.NET.Build.Containers versions 8.0.200+ includes some additional inferencing logic, for example to target Alpine. Earlier SDKs require more manual operations.
With the 8.0.1xx using the 8.0.1xx package, ContainerFamily must be used to target Alpine.
$ dotnet --version
8.0.102
$ cat dotnetapp.csproj | grep Package
<PackageReference Include="Microsoft.NET.Build.Containers" Version="8.0.103" />
$ dotnet publish --os linux-musl -t:PublishContainer
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.
$ dotnet publish --os linux-musl -t:PublishContainer -p:ContainerFamily=alpine
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0-alpine'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.
$ docker run --rm dotnetapp
42
42 ,d ,d
42 42 42
,adPPYb,42 ,adPPYba, MM42MMM 8b,dPPYba, ,adPPYba, MM42MMM
a8" `Y42 a8" "8a 42 42P' `"8a a8P_____42 42
8b 42 8b d8 42 42 42 8PP!!!!!!! 42
"8a, ,d42 "8a, ,a8" 42, 42 42 "8b, ,aa 42,
`"8bbdP"Y8 `"YbbdP"' "Y428 42 42 `"Ybbd8"' "Y428
OSArchitecture: X64
OSDescription: Alpine Linux v3.19
FrameworkDescription: .NET 8.0.3
UserName: app
HostName : 8d19c0223a1b
ProcessorCount: 8
TotalAvailableMemoryBytes: 67382329344 (62.75 GiB)With the 8.0.1xx using the 8.0.2xx package, automatic inferencing selects the correct base image.
rich@mazama:~/git/dotnet-docker/samples/dotnetapp$ dotnet --version
8.0.102
rich@mazama:~/git/dotnet-docker/samples/dotnetapp$ cat dotnetapp.csproj | grep Package
<PackageReference Include="Microsoft.NET.Build.Containers" Version="8.0.202" />
rich@mazama:~/git/dotnet-docker/samples/dotnetapp$ dotnet publish --os linux-musl -t:PublishContainer
/home/rich/.nuget/packages/microsoft.net.build.containers/8.0.202/build/Microsoft.NET.Build.Containers.targets(194,5): warning : Microsoft.NET.Build.Containers NuGet package is explicitly referenced. Consider removing the package reference to Microsoft.NET.Build.Containers as it is now part of .NET SDK. [/home/rich/git/dotnet-docker/samples/dotnetapp/dotnetapp.csproj]
dotnetapp -> /home/rich/git/dotnet-docker/samples/dotnetapp/bin/Release/net8.0/linux-musl-x64/publish/
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0-alpine'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.The same is true with 8.0.2xx SDK is used with no package.
$ dotnet --version
8.0.203
$ cat dotnetapp.csproj | grep Package
$ dotnet publish --os linux-musl -t:PublishContainer -p:EnableSdkContainerSupport=true
Building image 'dotnetapp' with tags 'latest' on top of base image 'mcr.microsoft.com/dotnet/runtime:8.0-alpine'.
Pushed image 'dotnetapp:latest' to local registry via 'docker'.