Missing app-engine-java components

[elharo]

We do not recognize or handle the case where gcloud is installed but the app-engine-java components are not:

If not previously installed, install the app-engine-java components into the gcloud SDK: $ gcloud components install app-engine-java

They are not installed by default with the gcloud SDK, and need to be installed as an extra step.

[akerekes]

Should not installing components be part of the common-lib?

[elharo]

Possibly. If they aren't, though, we at least need to give a better error message on our end.

[elharo]

Yes

[YnR]

Should also check that the right SDK folder was passed. I gave it the bin, and it failed silently.

[briandealwis]

@YnR how did you "give it the bin"? Via the GOOGLE_CLOUD_SDK_HOME env var, or via the Google Cloud Platform preference page? If the latter, there should have been a warning if the directory didn't validate.

[elharo]

Initial check is committed. We should still add a better message telling the user what to do when they hit this. Possibly with a hidden label saying to run

gcloud components install app-engine-java

at command line

[branflake2267]

The link to installing the sdk in the preferences dialog is opaque because it doesn't mention App Engine.

[elharo]

We only validate the app engine java components when the cloud SDK location is explicitly changed. We don't do this when a project is created.