Automatic merge from submit-queue (batch tested with PRs 51574, 51534, 49257, 44680, 48836)
update scheduler to return structured errors instead of process exit
The scheduler Run method returns an error that is properly handled at higher levels. Instead of existing the process, we should return the error and handle it at higher level logic to allow testing of error conditions and composition of commands. The changes are relatively minor.
@sjenning @aveshagarwal
Previously, the scheduler created two separate list watchers. This
changes the scheduler to be able to leverage a shared informer, whether
passed in externally or spawned using the new in place method. This
removes the last use of a "special" informer in the codebase.
Allows someone wrapping the scheduler to use a shared informer if they
have more information avaliable.
Where possible, switch the scheduler to use generated listers and
informers. There are still some places where it probably makes more
sense to use one-off reflectors/informers (listing/watching just a
single node, listing/watching scheduled & unscheduled pods using a field
selector).
Automatic merge from submit-queue (batch tested with PRs 39538, 40188, 40357, 38214, 40195)
Decoupling scheduler creation from creation of scheduler.Config struc…
**What this PR does / why we need it**:
Adds functionality to the scheduler to initialize from an Configurator interface, rather then via a Config struct.
**Which issue this PR fixes**
Reduces coupling to `scheduler.Config` data structure format so that we can proliferate more interface driven composition of scheduler components.
Automatic merge from submit-queue (batch tested with PRs 36263, 36755, 37357, 37222, 37524)
Add flag to enable contention profiling in scheduler.
```release-note
Add flag to enable contention profiling in scheduler.
```
Automatic merge from submit-queue
Add error log for Run function in server.go
When clientcmd.BuildConfigFromFlags and os.Hostname return error, there are no log information in Run function, neither did the upper function(main of scheduler), add it, I suggest.
