Duplicated IntelliSense with YAML + Docker extension

As our team has added the Docker Compose Language service to yaml files that are given the Docker Compose language designation in VS Code, users are getting dual suggestions in IntelliSense if they have the Docker extension installed.

Original Issue: https://github.com/microsoft/vscode-docker/issues/3480

Our suggestion would be, could there be a setting or an experience to suppress these suggestions if

Options:

1. Docker extension is detected and the user gives a Docker Compose file designation in VS Code
2. User has a file named docker-compose.yml

I like the first option. Althrough the majority of users name their Docker Compose file docker-compose.yml, this provides the greatest flexibility.

Adding @bwateratmsft

[bwateratmsft]

It would partway fix it, but if YAML got activated anyway for another reason, this would still occur. I talked to @isidorn and there’s not an existing way in VSCode to choose one language server or another. I think the “best” solution would be a shared setting between Docker and YAML; an easier solution would be a setting in YAML to turn off for dockercompose language entirely (including the language client document selector), but would require the user to manage two separate settings.

I don’t think it’s particularly urgent; as a workaround the Docker extension has a setting to disable its language server for compose, leaving only the YAML one.

[fbricon]

Other vscode extensions, like Kubernetes simply contribute new functionalities (validation/completion) to the yaml language server by injecting a custom schema, that can be computed on-the-fly. See https://github.com/vscode-kubernetes-tools/vscode-kubernetes-tools/blob/92582a57ce722e166d25482b443c37a58d16305a/src/yaml-support/yaml-schema.ts.