Merge pull request #310 from weaveworks/canary-promotion

Canary promotion improvements

artifacts/flagger/crd.yaml

@@ -254,6 +254,7 @@ spec:
                 - Initialized
                 - Waiting
                 - Progressing
+                - Promoting
                 - Finalising
                 - Succeeded
                 - Failed

charts/flagger/templates/crd.yaml

@@ -255,6 +255,7 @@ spec:
                 - Initialized
                 - Waiting
                 - Progressing
+                - Promoting
                 - Finalising
                 - Succeeded
                 - Failed

docs/gitbook/how-it-works.md

@@ -143,7 +143,7 @@ status:
 ```
 
 The `Promoted` status condition can have one of the following reasons:
-Initialized, Waiting, Progressing, Finalising, Succeeded or Failed.
+Initialized, Waiting, Progressing, Promoting, Finalising, Succeeded or Failed.
 A failed canary will have the promoted status set to `false`,
 the reason to `failed` and the last applied spec will be different to the last promoted one.
 
@@ -153,6 +153,26 @@ Wait for a successful rollout:
 kubectl wait canary/podinfo --for=condition=promoted
 ```
 
+CI example:
+
+```bash
+# update the container image
+kubectl set image deployment/podinfo podinfod=stefanprodan/podinfo:3.0.1
+
+# wait for Flagger to detect the change
+ok=false
+until ${ok}; do
+    kubectl get canary/podinfo | grep 'Progressing' && ok=true || ok=false
+    sleep 5
+done
+
+# wait for the canary analysis to finish
+kubectl wait canary/podinfo --for=condition=promoted --timeout=5m
+
+# check if the deployment was successful 
+kubectl get canary/podinfo | grep Succeeded
+```
+
 ### Istio routing
 
 Flagger creates an Istio Virtual Service and Destination Rules based on the Canary service spec. 
@@ -344,12 +364,13 @@ A canary deployment is triggered by changes in any of the following objects:
 Gated canary promotion stages:
 
 * scan for canary deployments
-* check Istio virtual service routes are mapped to primary and canary ClusterIP services
-* check primary and canary deployments status
+* check primary and canary deployment status
     * halt advancement if a rolling update is underway
     * halt advancement if pods are unhealthy
-* call pre-rollout webhooks are check results
-    * halt advancement if any hook returned a non HTTP 2xx result
+* call confirm-rollout webhooks and check results
+    * halt advancement if any hook returns a non HTTP 2xx result
+* call pre-rollout webhooks and check results
+    * halt advancement if any hook returns a non HTTP 2xx result
     * increment the failed checks counter
 * increase canary traffic weight percentage from 0% to 5% (step weight)
 * call rollout webhooks and check results
@@ -366,8 +387,11 @@ Gated canary promotion stages:
     * halt advancement if any webhook call fails
     * halt advancement while canary request success rate is under the threshold
     * halt advancement while canary request duration P99 is over the threshold
+    * halt advancement while any custom metric check fails
     * halt advancement if the primary or canary deployment becomes unhealthy 
     * halt advancement while canary deployment is being scaled up/down by HPA
+* call confirm-promotion webhooks and check results
+    * halt advancement if any hook returns a non HTTP 2xx result
 * promote canary to primary
     * copy ConfigMaps and Secrets from canary to primary
     * copy canary deployment spec template over primary
@@ -377,7 +401,7 @@ Gated canary promotion stages:
 * scale to zero the canary deployment
 * mark rollout as finished
 * call post-rollout webhooks
-* post the analysis result to Slack
+* post the analysis result to Slack or MS Teams
 * wait for the canary deployment to be updated and start over
 
 ### Canary Analysis

kustomize/base/flagger/crd.yaml

@@ -254,6 +254,7 @@ spec:
                 - Initialized
                 - Waiting
                 - Progressing
+                - Promoting
                 - Finalising
                 - Succeeded
                 - Failed

pkg/apis/flagger/v1alpha3/status.go

@@ -47,7 +47,9 @@ const (
 	CanaryPhaseWaiting CanaryPhase = "Waiting"
 	// CanaryPhaseProgressing means the canary analysis is underway
 	CanaryPhaseProgressing CanaryPhase = "Progressing"
-	// CanaryPhaseProgressing means the canary analysis is finished and traffic has been routed back to primary
+	// CanaryPhasePromoting means the canary analysis is finished and the primary spec has been updated
+	CanaryPhasePromoting CanaryPhase = "Promoting"
+	// CanaryPhaseProgressing means the canary promotion is finished and traffic has been routed back to primary
 	CanaryPhaseFinalising CanaryPhase = "Finalising"
 	// CanaryPhaseSucceeded means the canary analysis has been successful
 	// and the canary deployment has been promoted

pkg/canary/status.go

@@ -211,6 +211,9 @@ func (c *Deployer) MakeStatusConditions(canaryStatus flaggerv1.CanaryStatus,
 	case flaggerv1.CanaryPhaseProgressing:
 		status = corev1.ConditionUnknown
 		message = "New revision detected, starting canary analysis."
+	case flaggerv1.CanaryPhasePromoting:
+		status = corev1.ConditionUnknown
+		message = "Canary analysis completed, starting primary rolling update."
 	case flaggerv1.CanaryPhaseFinalising:
 		status = corev1.ConditionUnknown
 		message = "Canary analysis completed, routing all traffic to primary."

pkg/controller/scheduler.go

@@ -214,7 +214,27 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		return
 	}
 
-	// scale canary to zero if analysis has succeeded
+	// route all traffic to primary if analysis has succeeded
+	if cd.Status.Phase == flaggerv1.CanaryPhasePromoting {
+		if provider != "kubernetes" {
+			c.recordEventInfof(cd, "Routing all traffic to primary")
+			if err := meshRouter.SetRoutes(cd, 100, 0); err != nil {
+				c.recordEventWarningf(cd, "%v", err)
+				return
+			}
+			c.recorder.SetWeight(cd, 100, 0)
+		}
+
+		// update status phase
+		if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhaseFinalising); err != nil {
+			c.recordEventWarningf(cd, "%v", err)
+			return
+		}
+
+		return
+	}
+
+	// scale canary to zero if promotion has finished
 	if cd.Status.Phase == flaggerv1.CanaryPhaseFinalising {
 		if err := c.deployer.Scale(cd, 0); err != nil {
 			c.recordEventWarningf(cd, "%v", err)
@@ -304,7 +324,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		}
 	}
 
-	// canary fix routing: A/B testing
+	// strategy: A/B testing
 	if len(cd.Spec.CanaryAnalysis.Match) > 0 && cd.Spec.CanaryAnalysis.Iterations > 0 {
 		// route traffic to canary and increment iterations
 		if cd.Spec.CanaryAnalysis.Iterations > cd.Status.Iterations {
@@ -336,38 +356,19 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
-			// increment iterations
-			if err := c.deployer.SetStatusIterations(cd, cd.Status.Iterations+1); err != nil {
-				c.recordEventWarningf(cd, "%v", err)
-				return
-			}
-			return
-		}
-
-		// route all traffic to primary
-		if cd.Spec.CanaryAnalysis.Iterations < cd.Status.Iterations {
-			primaryWeight = 100
-			canaryWeight = 0
-			if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
-				c.recordEventWarningf(cd, "%v", err)
-				return
-			}
-			c.recorder.SetWeight(cd, primaryWeight, canaryWeight)
 
 			// update status phase
-			if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhaseFinalising); err != nil {
+			if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhasePromoting); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
-
-			c.recordEventInfof(cd, "Routing all traffic to primary")
 			return
 		}
 
 		return
 	}
 
-	// canary fix routing: B/G
+	// strategy: Blue/Green
 	if cd.Spec.CanaryAnalysis.Iterations > 0 {
 		// increment iterations
 		if cd.Spec.CanaryAnalysis.Iterations > cd.Status.Iterations {
@@ -405,105 +406,79 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		}
 
 		// promote canary - max iterations reached
-		if cd.Spec.CanaryAnalysis.Iterations+1 == cd.Status.Iterations {
+		if cd.Spec.CanaryAnalysis.Iterations < cd.Status.Iterations {
 			c.recordEventInfof(cd, "Copying %s.%s template spec to %s.%s",
 				cd.Spec.TargetRef.Name, cd.Namespace, primaryName, cd.Namespace)
 			if err := c.deployer.Promote(cd); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
 
-			// increment iterations
-			if err := c.deployer.SetStatusIterations(cd, cd.Status.Iterations+1); err != nil {
+			// update status phase
+			if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhasePromoting); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
 			return
 		}
 
-		// route all traffic to primary
-		if cd.Spec.CanaryAnalysis.Iterations < cd.Status.Iterations {
-			if provider != "kubernetes" {
-				c.recordEventInfof(cd, "Routing all traffic to primary")
-				if err := meshRouter.SetRoutes(cd, 100, 0); err != nil {
-					c.recordEventWarningf(cd, "%v", err)
-					return
-				}
-				c.recorder.SetWeight(cd, 100, 0)
+		return
+	}
+
+	// strategy: Canary progressive traffic increase
+	if cd.Spec.CanaryAnalysis.StepWeight > 0 {
+		// increase traffic weight
+		if canaryWeight < maxWeight {
+			primaryWeight -= cd.Spec.CanaryAnalysis.StepWeight
+			if primaryWeight < 0 {
+				primaryWeight = 0
+			}
+			canaryWeight += cd.Spec.CanaryAnalysis.StepWeight
+			if canaryWeight > 100 {
+				canaryWeight = 100
 			}
 
-			// update status phase
-			if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhaseFinalising); err != nil {
+			if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
 
-			return
-		}
-
-		return
-	}
+			if err := c.deployer.SetStatusWeight(cd, canaryWeight); err != nil {
+				c.recordEventWarningf(cd, "%v", err)
+				return
+			}
 
-	// canary incremental traffic weight
-	if canaryWeight < maxWeight {
-		primaryWeight -= cd.Spec.CanaryAnalysis.StepWeight
-		if primaryWeight < 0 {
-			primaryWeight = 0
-		}
-		canaryWeight += cd.Spec.CanaryAnalysis.StepWeight
-		if primaryWeight > 100 {
-			primaryWeight = 100
+			c.recorder.SetWeight(cd, primaryWeight, canaryWeight)
+			c.recordEventInfof(cd, "Advance %s.%s canary weight %v", cd.Name, cd.Namespace, canaryWeight)
+			return
 		}
 
-		// check promotion gate
+		// promote canary - max weight reached
 		if canaryWeight >= maxWeight {
+			// check promotion gate
 			if promote := c.runConfirmPromotionHooks(cd); !promote {
 				return
 			}
-		}
-
-		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
-			c.recordEventWarningf(cd, "%v", err)
-			return
-		}
-
-		// update weight status
-		if err := c.deployer.SetStatusWeight(cd, canaryWeight); err != nil {
-			c.recordEventWarningf(cd, "%v", err)
-			return
-		}
 
-		c.recorder.SetWeight(cd, primaryWeight, canaryWeight)
-		c.recordEventInfof(cd, "Advance %s.%s canary weight %v", cd.Name, cd.Namespace, canaryWeight)
-
-		// promote canary
-		if canaryWeight >= maxWeight {
+			// update primary spec
 			c.recordEventInfof(cd, "Copying %s.%s template spec to %s.%s",
 				cd.Spec.TargetRef.Name, cd.Namespace, primaryName, cd.Namespace)
 			if err := c.deployer.Promote(cd); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
-		}
-	} else {
-		// route all traffic to primary
-		primaryWeight = 100
-		canaryWeight = 0
-		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
-			c.recordEventWarningf(cd, "%v", err)
-			return
-		}
-		c.recorder.SetWeight(cd, primaryWeight, canaryWeight)
 
-		// update status phase
-		if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhaseFinalising); err != nil {
-			c.recordEventWarningf(cd, "%v", err)
+			// update status phase
+			if err := c.deployer.SetStatusPhase(cd, flaggerv1.CanaryPhasePromoting); err != nil {
+				c.recordEventWarningf(cd, "%v", err)
+				return
+			}
+
 			return
 		}
 
-		c.recordEventInfof(cd, "Routing all traffic to primary")
-		return
 	}
+
 }
 
 func (c *Controller) shouldSkipAnalysis(cd *flaggerv1.Canary, meshRouter router.Interface, primaryWeight int, canaryWeight int) bool {
@@ -555,6 +530,7 @@ func (c *Controller) shouldAdvance(cd *flaggerv1.Canary) (bool, error) {
 		cd.Status.Phase == flaggerv1.CanaryPhaseInitializing ||
 		cd.Status.Phase == flaggerv1.CanaryPhaseProgressing ||
 		cd.Status.Phase == flaggerv1.CanaryPhaseWaiting ||
+		cd.Status.Phase == flaggerv1.CanaryPhasePromoting ||
 		cd.Status.Phase == flaggerv1.CanaryPhaseFinalising {
 		return true, nil
 	}
@@ -579,6 +555,7 @@ func (c *Controller) shouldAdvance(cd *flaggerv1.Canary) (bool, error) {
 func (c *Controller) checkCanaryStatus(cd *flaggerv1.Canary, shouldAdvance bool) bool {
 	c.recorder.SetStatus(cd, cd.Status.Phase)
 	if cd.Status.Phase == flaggerv1.CanaryPhaseProgressing ||
+		cd.Status.Phase == flaggerv1.CanaryPhasePromoting ||
 		cd.Status.Phase == flaggerv1.CanaryPhaseFinalising {
 		return true
 	}