Multiple .NET SDK versions?

[justinyoo]

Hi, Team.

I was wondering if it's possible to install multiple .NET SDKs in one devcontainer settings. For example, I'd like to install both .NET 7 and .NET 6 in one devcontainer environment.

What I tried was:

1. In Dockerfile, select the base container image from mcr.microsoft.com/dotnet/sdk:7.0
2. In devcontainer.json, run a shell script, say post-create.sh, through postCreateCommand.
3. In post-create.sh, run the dotnet-install.sh script by following this document to install .NET 6.

However, it didn't go well as intended. Would you be able to provide some guidance to install multiple .NET SDK versions - STS and LTS?

Cheers,

[samruddhikhandale]

Option 1 - The mcr.microsoft.com/devcontainers/universal:2 consists of .NET 7 & 6. Maybe you could use that as the base container image?

Option 2 - We have an experimental additionalVersions option for some of the Features to install more than one SDKs. The value specified for version option is set as default.

Can you try adding the following to .devcontainer.json?

"features": {
        "ghcr.io/devcontainers/features/dotnet:1": {
            "version": "7",
            "additionalVersions": "6"
        }
    }

[justinyoo]

Oh, I might try the Option 2, then. Thanks!

[justinyoo]

By the way, devcontainer-feature.json doesn't define the additionalVersions option, but install.sh defines it. Have you noticed that?

[samruddhikhandale]

Option 2 - We have an experimental additionalVersions option for some of the Features to install more than one SDKs. The value specified for version option is set as default.

@justinyoo Yep, we had added it as an experimental option and hence, didn't document it. As we can see a request for it, we'd think of either formalizing that option or finding another better approach for this scenario.

[kosperera]

Option 2 - We have an experimental additionalVersions option for some of the Features to install more than one SDKs. The value specified for version option is set as default.

Can you try adding the following to .devcontainer.json?

"features": {
        "ghcr.io/devcontainers/features/dotnet:1": {
            "version": "7",
            "additionalVersions": "6"
        }
    }

Hi @justinyoo were you able to make it work? I tried this Option 2 but the install script is not installing the additional versions.

[iMicknl]

Adding additionalVersions does not work for me as well. With "image": "mcr.microsoft.com/devcontainers/universal:2" it fails on dotnet 6 already exists. While if I remove the dotnet feature, only dotnet 7 is present (runtime and SDK).

#0 80.55 Found .NET binary version 6.0.408
#0 80.83 (!) Dotnet version 6.0.408 already exists.
#0 80.83 ERROR: Feature "Dotnet CLI" (ghcr.io/devcontainers/features/dotnet) failed to install! Look at the documentation at https://github.com/devcontainers/features/tree/main/src/dotnet for help troubleshooting this error.

{
	"image": "mcr.microsoft.com/devcontainers/universal:2",
	"features": {
		"ghcr.io/devcontainers/features/node:latest": {},
		"ghcr.io/devcontainers/features/dotnet:latest": {
			"version": "7",
            "additionalVersions": "6"
		},
		"ghcr.io/jlaundry/devcontainer-features/azure-functions-core-tools:latest": {}
	},