Simple trigger of rollback via status phase

[fblgit]

Describe the feature

A simple mechanism to trigger a rollback on a canary by merely patching status phase

Proposed solution

Similarly to #1252

• Introduce CanaryPhase pkg/apis/flagger/v1beta1/status.go and pkg/canary/status.go
• Update artifacts/flagger/crd.yaml kustomize/base/flagger/crd.yaml and charts/flagger/crds/crd.yaml
• Add a new condition to trigger runRollbackHooks or rollback across pkg/controller/scheduler.go
• Add a test case on pkg/controller/webhook_test.go to validate the rollback

Any alternatives you've considered?

There may be other ways to implement it, open to suggestions and i'll be happy to push a PR for it.

[fblgit]

@stefanprodan will a PR like this be merged ? Or you have any other implementation idea that u'd like me to take a look?

[aryan9600]

this should be possible to achieve by patching .status.failedChecks to be >= .spec.threshold.