diff --git a/docs/README.md b/docs/README.md index 1fde984a0..97aeb17c4 100644 --- a/docs/README.md +++ b/docs/README.md @@ -2,6 +2,7 @@ [![build](https://travis-ci.org/stefanprodan/flagger.svg?branch=master)](https://travis-ci.org/stefanprodan/flagger) [![report](https://goreportcard.com/badge/github.com/stefanprodan/flagger)](https://goreportcard.com/report/github.com/stefanprodan/flagger) +[![codecov](https://codecov.io/gh/stefanprodan/flagger/branch/master/graph/badge.svg)](https://codecov.io/gh/stefanprodan/flagger) [![license](https://img.shields.io/github/license/stefanprodan/flagger.svg)](https://github.com/stefanprodan/flagger/blob/master/LICENSE) [![release](https://img.shields.io/github/release/stefanprodan/flagger/all.svg)](https://github.com/stefanprodan/flagger/releases) @@ -19,7 +20,7 @@ Deploy Flagger in the `istio-system` namespace using Helm: ```bash # add the Helm repository -helm repo add flagger https://stefanprodan.github.io/flagger +helm repo add flagger https://flagger.app # install or upgrade helm upgrade -i flagger flagger/flagger \ @@ -32,10 +33,11 @@ Flagger is compatible with Kubernetes >1.10.0 and Istio >1.0.0. ### Usage -Flagger requires two Kubernetes [deployments](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/): -one for the version you want to upgrade called _primary_ and one for the _canary_. -Each deployment must have a corresponding ClusterIP [service](https://kubernetes.io/docs/concepts/services-networking/service/) -that exposes a port named http or https. These services are used as destinations in a Istio [virtual service](https://istio.io/docs/reference/config/istio.networking.v1alpha3/#VirtualService). +Flagger takes a Kubernetes deployment and creates a series of objects +(Kubernetes [deployments](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/), +ClusterIP [services](https://kubernetes.io/docs/concepts/services-networking/service/) and +Istio [virtual services](https://istio.io/docs/reference/config/istio.networking.v1alpha3/#VirtualService)) +to drive the canary analysis and promotion. ![flagger-overview](https://github.com/raw/stefanprodan/flagger/master/docs/diagrams/flagger-overview.png) @@ -44,25 +46,25 @@ 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 - * halt rollout if a rolling update is underway - * halt rollout if pods are unhealthy + * halt advancement if a rolling update is underway + * halt advancement if pods are unhealthy * increase canary traffic weight percentage from 0% to 5% (step weight) * check canary HTTP request success rate and latency - * halt rollout if any metric is under the specified threshold + * halt advancement if any metric is under the specified threshold * increment the failed checks counter * check if the number of failed checks reached the threshold * route all traffic to primary * scale to zero the canary deployment and mark it as failed * wait for the canary deployment to be updated (revision bump) and start over * increase canary traffic weight by 5% (step weight) till it reaches 50% (max weight) - * halt rollout while canary request success rate is under the threshold - * halt rollout while canary request duration P99 is over the threshold - * halt rollout if the primary or canary deployment becomes unhealthy - * halt rollout while canary deployment is being scaled up/down by HPA + * halt advancement while canary request success rate is under the threshold + * halt advancement while canary request duration P99 is over the threshold + * halt advancement if the primary or canary deployment becomes unhealthy + * halt advancement while canary deployment is being scaled up/down by HPA * promote canary to primary * copy canary deployment spec template over primary * wait for primary rolling update to finish - * halt rollout if pods are unhealthy + * halt advancement if pods are unhealthy * route all traffic to primary * scale to zero the canary deployment * mark rollout as finished @@ -70,76 +72,43 @@ Gated canary promotion stages: You can change the canary analysis _max weight_ and the _step weight_ percentage in the Flagger's custom resource. -Assuming the primary deployment is named _podinfo_ and the canary one _podinfo-canary_, Flagger will require -a virtual service configured with weight-based routing: +For a deployment named _podinfo_, a canary promotion can be defined using Flagger's custom resource: ```yaml -apiVersion: networking.istio.io/v1alpha3 -kind: VirtualService -metadata: - name: podinfo -spec: - hosts: - - podinfo - http: - - route: - - destination: - host: podinfo - port: - number: 9898 - weight: 100 - - destination: - host: podinfo-canary - port: - number: 9898 - weight: 0 -``` - -Primary and canary services should expose a port named http: - -```yaml -apiVersion: v1 -kind: Service -metadata: - name: podinfo-canary -spec: - type: ClusterIP - selector: - app: podinfo-canary - ports: - - name: http - port: 9898 - targetPort: 9898 -``` - -Based on the two deployments, services and virtual service, a canary promotion can be defined using Flagger's custom resource: - -```yaml -apiVersion: flagger.app/v1beta1 +apiVersion: flagger.app/v1alpha1 kind: Canary metadata: name: podinfo namespace: test spec: - targetKind: Deployment - virtualService: + # deployment reference + targetRef: + apiVersion: apps/v1 + kind: Deployment name: podinfo - primary: + # hpa reference (optional) + autoscalerRef: + apiVersion: autoscaling/v2beta1 + kind: HorizontalPodAutoscaler name: podinfo - host: podinfo - canary: - name: podinfo-canary - host: podinfo-canary + service: + # container port + port: 9898 + # Istio gateways (optional) + gateways: + - public-gateway.istio-system.svc.cluster.local + # Istio virtual service host names (optional) + hosts: + - app.istio.weavedx.com canaryAnalysis: - # max number of failed checks - # before rolling back the canary - threshold: 10 + # max number of failed metric checks before rollback + threshold: 5 # max traffic percentage routed to canary # percentage (0-100) maxWeight: 50 # canary increment step # percentage (0-100) - stepWeight: 5 + stepWeight: 10 metrics: - name: istio_requests_total # minimum req success rate (non 5xx responses) @@ -150,14 +119,14 @@ spec: # maximum req duration P99 # milliseconds threshold: 500 - interval: 1m + interval: 30s ``` The canary analysis is using the following promql queries: _HTTP requests success rate percentage_ -```promql +```sql sum( rate( istio_requests_total{ @@ -182,7 +151,7 @@ sum( _HTTP requests milliseconds duration P99_ -```promql +```sql histogram_quantile(0.99, sum( irate( @@ -198,8 +167,6 @@ histogram_quantile(0.99, ### Automated canary analysis, promotions and rollbacks -![flagger-canary](https://github.com/raw/stefanprodan/flagger/master/docs/diagrams/flagger-canary-hpa.png) - Create a test namespace with Istio sidecar injection enabled: ```bash @@ -208,66 +175,72 @@ export REPO=https://github.com/raw/stefanprodan/flagger/master kubectl apply -f ${REPO}/artifacts/namespaces/test.yaml ``` -Create the primary deployment, service and hpa: +Create a deployment and a horizontal pod autoscaler: ```bash -kubectl apply -f ${REPO}/artifacts/workloads/primary-deployment.yaml -kubectl apply -f ${REPO}/artifacts/workloads/primary-service.yaml -kubectl apply -f ${REPO}/artifacts/workloads/primary-hpa.yaml +kubectl apply -f ${REPO}/artifacts/canaries/deployment.yaml +kubectl apply -f ${REPO}/artifacts/canaries/hpa.yaml ``` -Create the canary deployment, service and hpa: +Create a canary promotion custom resource (replace the Istio gateway and the internet domain with your own): ```bash -kubectl apply -f ${REPO}/artifacts/workloads/canary-deployment.yaml -kubectl apply -f ${REPO}/artifacts/workloads/canary-service.yaml -kubectl apply -f ${REPO}/artifacts/workloads/canary-hpa.yaml +kubectl apply -f ${REPO}/artifacts/canaries/canary.yaml ``` -Create a virtual service (replace the Istio gateway and the internet domain with your own): +After a couple of seconds Flagger will create the canary objects: ```bash -kubectl apply -f ${REPO}/artifacts/workloads/virtual-service.yaml +# applied +deployment.apps/podinfo +horizontalpodautoscaler.autoscaling/podinfo +canary.flagger.app/podinfo +# generated +deployment.apps/podinfo-primary +horizontalpodautoscaler.autoscaling/podinfo-primary +service/podinfo +service/podinfo-canary +service/podinfo-primary +virtualservice.networking.istio.io/podinfo ``` -Create a canary promotion custom resource: +![flagger-canary-steps](https://github.com/raw/stefanprodan/flagger/master/docs/diagrams/flagger-canary-steps.png) + +Trigger a canary deployment by updating the container image: ```bash -kubectl apply -f ${REPO}/artifacts/rollouts/podinfo.yaml +kubectl -n test set image deployment/podinfo \ +podinfod=quay.io/stefanprodan/podinfo:1.2.1 ``` -Canary promotion output: +Flagger detects that the deployment revision changed and starts a new rollout: ``` kubectl -n test describe canary/podinfo Status: - Canary Revision: 16271121 - Failed Checks: 6 + Canary Revision: 19871136 + Failed Checks: 0 State: finished Events: Type Reason Age From Message ---- ------ ---- ---- ------- - Normal Synced 3m flagger Starting canary deployment for podinfo.test + Normal Synced 3m flagger New revision detected podinfo.test + Normal Synced 3m flagger Scaling up podinfo.test + Warning Synced 3m flagger Waiting for podinfo.test rollout to finish: 0 of 1 updated replicas are available Normal Synced 3m flagger Advance podinfo.test canary weight 5 Normal Synced 3m flagger Advance podinfo.test canary weight 10 Normal Synced 3m flagger Advance podinfo.test canary weight 15 - Warning Synced 3m flagger Halt podinfo.test advancement request duration 2.525s > 500ms - Warning Synced 3m flagger Halt podinfo.test advancement request duration 1.567s > 500ms - Warning Synced 3m flagger Halt podinfo.test advancement request duration 823ms > 500ms Normal Synced 2m flagger Advance podinfo.test canary weight 20 Normal Synced 2m flagger Advance podinfo.test canary weight 25 Normal Synced 1m flagger Advance podinfo.test canary weight 30 - Warning Synced 1m flagger Halt podinfo.test advancement success rate 82.33% < 99% - Warning Synced 1m flagger Halt podinfo.test advancement success rate 87.22% < 99% - Warning Synced 1m flagger Halt podinfo.test advancement success rate 94.74% < 99% Normal Synced 1m flagger Advance podinfo.test canary weight 35 Normal Synced 55s flagger Advance podinfo.test canary weight 40 Normal Synced 45s flagger Advance podinfo.test canary weight 45 Normal Synced 35s flagger Advance podinfo.test canary weight 50 - Normal Synced 25s flagger Copying podinfo-canary.test template spec to podinfo.test - Warning Synced 15s flagger Waiting for podinfo.test rollout to finish: 1 of 2 updated replicas are available - Normal Synced 5s flagger Promotion completed! Scaling down podinfo-canary.test + Normal Synced 25s flagger Copying podinfo.test template spec to podinfo-primary.test + Warning Synced 15s flagger Waiting for podinfo-primary.test rollout to finish: 1 of 2 updated replicas are available + Normal Synced 5s flagger Promotion completed! Scaling down podinfo.test ``` During the canary analysis you can generate HTTP 500 errors and high latency to test if Flagger pauses the rollout. @@ -313,45 +286,8 @@ Events: Normal Synced 2m flagger Halt podinfo.test advancement success rate 55.06% < 99% Normal Synced 2m flagger Halt podinfo.test advancement success rate 47.00% < 99% Normal Synced 2m flagger (combined from similar events): Halt podinfo.test advancement success rate 38.08% < 99% - Warning Synced 1m flagger Rolling back podinfo-canary.test failed checks threshold reached 10 - Warning Synced 1m flagger Canary failed! Scaling down podinfo-canary.test -``` - -Trigger a new canary deployment by updating the canary image: - -```bash -kubectl -n test set image deployment/podinfo-canary \ -podinfod=quay.io/stefanprodan/podinfo:1.2.1 -``` - -Steer detects that the canary revision changed and starts a new rollout: - -``` -kubectl -n test describe canary/podinfo - -Status: - Canary Revision: 19871136 - Failed Checks: 0 - State: finished -Events: - Type Reason Age From Message - ---- ------ ---- ---- ------- - Normal Synced 3m flagger New revision detected podinfo-canary.test old 17211012 new 17246876 - Normal Synced 3m flagger Scaling up podinfo.test - Warning Synced 3m flagger Waiting for podinfo.test rollout to finish: 0 of 1 updated replicas are available - Normal Synced 3m flagger Advance podinfo.test canary weight 5 - Normal Synced 3m flagger Advance podinfo.test canary weight 10 - Normal Synced 3m flagger Advance podinfo.test canary weight 15 - Normal Synced 2m flagger Advance podinfo.test canary weight 20 - Normal Synced 2m flagger Advance podinfo.test canary weight 25 - Normal Synced 1m flagger Advance podinfo.test canary weight 30 - Normal Synced 1m flagger Advance podinfo.test canary weight 35 - Normal Synced 55s flagger Advance podinfo.test canary weight 40 - Normal Synced 45s flagger Advance podinfo.test canary weight 45 - Normal Synced 35s flagger Advance podinfo.test canary weight 50 - Normal Synced 25s flagger Copying podinfo-canary.test template spec to podinfo.test - Warning Synced 15s flagger Waiting for podinfo.test rollout to finish: 1 of 2 updated replicas are available - Normal Synced 5s flagger Promotion completed! Scaling down podinfo-canary.test + Warning Synced 1m flagger Rolling back podinfo.test failed checks threshold reached 10 + Warning Synced 1m flagger Canary failed! Scaling down podinfo.test ``` ### Monitoring @@ -388,9 +324,22 @@ Advance podinfo.test canary weight 40 Halt podinfo.test advancement request duration 1.515s > 500ms Advance podinfo.test canary weight 45 Advance podinfo.test canary weight 50 -Copying podinfo-canary.test template spec to podinfo-primary.test -Scaling down podinfo-canary.test -Promotion completed! podinfo-canary.test revision 81289 +Copying podinfo.test template spec to podinfo-primary.test +Halt podinfo-primary.test advancement waiting for rollout to finish: 1 old replicas are pending termination +Scaling down podinfo.test +Promotion completed! podinfo.test +``` + +Flagger exposes Prometheus metrics that can be used to determine the canary analysis status and the destination weight values: + +```bash +# Canary status +# 0 - running, 1 - successful, 2 - failed +flagger_canary_status{name="podinfo" namespace="test"} 1 + +# Canary traffic weight +flagger_canary_weight{workload="podinfo-primary" namespace="test"} 95 +flagger_canary_weight{workload="podinfo" namespace="test"} 5 ``` ### Roadmap