Docker view keeps loading without any notification if there is no Docker Desktop installed

[v-ruizh]

OS: Win 10
Build Version: 20210809.1
Regression: Previous Release

Repro Steps:

1. Make sure there is no Docker Desktop on the machine.
2. Install the Docker extension in VS Code.
3. Open the Docker view.
4. Check whether a notification pops up to remind user to install Docker Desktop.

Expect:
A notification pops up to remind user to install Docker Desktop.

Actual:
Docker view keeps loading without any notification.

More Info:

1. This notification pops up after expanding the Networks/Volumes/Contexts view.
2. This issue does not reproduce on the previous released Docker extension 1.15.0.

[karolz-ms]

Side-effect of #3109 ?

[bwateratmsft]

Yeah, that was my thought too. Interesting that expanding other nodes seems to make it work. I'm less concerned about this and more concerned that the context lookup is swallowing errors with nothing being reported-- that's something I want to look into.

[bwateratmsft]

I'm able to reproduce. I think what is happening is the containers and images views start their first refresh call which awaits on ContextLoadingClient--which will not forward the call until it observes the onContextChanged event from the context manager. However, the event is only fired if no exception is thrown.

@karolz-ms I think maybe we should have two separate events in DockerContextManager, leave onContextChanged as it is now, but add one for onLoadingFinished specifically for ContextLoadingClient. This one would fire regardless of success/failure of context loading, i.e. by being in the finally. What do you think?

[karolz-ms]

@bwateratmsft yes, that makes sense to me.

[bwateratmsft]

Discussed offline and we'll fix this in 1.17.0.

[bwateratmsft]

The fix for this has been released in Docker extension 1.17.0.