feat: add ability to verify canary weights before advancing steps

[jessesuen]

Resolves #701

This introduces an optional flag to the controller --alb-verify-weight=true. When enabled, for ALB ingresses, the controller will block a setWeight step until it is verified applied in the ALB target group listener rules. This requires that the controller has sufficient AWS privileges.

Changes the TrafficRoutingReconciler interface from:

type TrafficRoutingReconciler interface {
	Reconcile(desiredWeight int32) error
}

to

type TrafficRoutingReconciler interface {
	// SetWeight sets the canary weight to the desired weight
	SetWeight(desiredWeight int32) error
	// VerifyWeight returns true if the canary is at the desired weight
	VerifyWeight(desiredWeight int32) (bool, error)
	// Type returns the type of the traffic routing reconciler
	Type() string		Type() string
}

to support this.

Signed-off-by: Jesse Suen jesse_suen@intuit.com

[codecov-io]

Codecov Report

Merging #957 (cfc0f8d) into master (1beffd4) will decrease coverage by 0.27%.
The diff coverage is 68.75%.

@@            Coverage Diff             @@
##           master     #957      +/-   ##
==========================================
- Coverage   81.60%   81.33%   -0.28%     
==========================================
  Files          99      100       +1     
  Lines        8732     8839     +107     
==========================================
+ Hits         7126     7189      +63     
- Misses       1151     1181      +30     
- Partials      455      469      +14     

Impacted Files	Coverage Δ
rollout/context.go	90.19% <ø> (ø)
rollout/trafficrouting/istio/istio.go	90.22% <0.00%> (-0.69%)	⬇️
rollout/trafficrouting/nginx/nginx.go	87.00% <0.00%> (-0.88%)	⬇️
rollout/trafficrouting/smi/smi.go	94.50% <0.00%> (-0.53%)	⬇️
rollout/trafficrouting/alb/alb.go	82.88% <57.50%> (-14.34%)	⬇️
utils/aws/aws.go	62.00% <62.00%> (ø)
rollout/canary.go	79.40% <81.81%> (-1.66%)	⬇️
ingress/alb.go	96.29% <100.00%> (ø)
rollout/trafficrouting.go	93.93% <100.00%> (+1.34%)	⬆️
pkg/kubectl-argo-rollouts/cmd/create/create.go	66.01% <0.00%> (ø)
... and 1 more

---

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[khhirani]

LGTM

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
25 Code Smells

No Coverage information
3.6% Duplication