This document describes how to upgrade Flagger.

Upgrade canaries v1alpha3 to v1beta1

Canary CRD changes in canaries.flagger.app/v1beta1:

• the spec.canaryAnalysis field has been deprecated and replaced with spec.analysis

• the spec.analysis.interval and spec.analysis.threshold fields are required

• the status.lastAppliedSpec and status.lastPromotedSpec hashing algorithm changed to hash/fnv

• the spec.analysis.alerts array can reference alertproviders.flagger.app/v1beta1 resources

• the spec.analysis.metrics[].templateRef can reference a metrictemplate.flagger.app/v1beta1 resource

• the metric.threshold field has been deprecated and replaced with metric.thresholdRange

• the metric.query field has been deprecated and replaced with metric.templateRef

• the spec.ingressRef.apiVersion accepts networking.k8s.io/v1beta1

• the spec.targetRef can reference DaemonSet kind

• the spec.service.meshName field has been deprecated and no longer used for provider: appmesh:v1beta2

Upgrade procedure:

• install the v1beta1 CRDs

• update Flagger deployment

• replace apiVersion: flagger.app/v1alpha3 with apiVersion: flagger.app/v1beta1 in all canary manifests

• replace spec.canaryAnalysis with spec.analysis in all canary manifests

• update canary manifests in cluster

Note that after upgrading Flagger, all canaries will be triggered as the hash value used for tracking changes is computed differently. You can set spec.skipAnalysis: true in all canary manifests before upgrading Flagger, do the upgrade, wait for Flagger to finish the no-op promotions and finally set skipAnalysis to false.

Update builtin metrics:

• replace threshold with thresholdRange.min for request-success-rate

• replace threshold with thresholdRange.max for request-duration

metrics:
- name: request-success-rate
  thresholdRange:
    min: 99
  interval: 1m
- name: request-duration
  thresholdRange:
    max: 500
  interval: 1m

Istio telemetry v2

Istio 1.5 comes with a breaking change for Flagger uses. In Istio telemetry v2 the metric istio_request_duration_seconds_bucket has been removed and replaced with istio_request_duration_milliseconds_bucket and this breaks the request-duration metric check.

You can create a metric template using the new duration metric like this:

apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
  name: latency
  namespace: istio-system
spec:
  provider:
    type: prometheus
    address: http://prometheus.istio-system:9090
  query: |
    histogram_quantile(
        0.99,
        sum(
            rate(
                istio_request_duration_milliseconds_bucket{
                    reporter="destination",
                    destination_workload_namespace="{{ namespace }}",
                    destination_workload=~"{{ target }}"
                }[{{ interval }}]
            )
        ) by (le)
    )

In the canary manifests, replace the request-duration metric with latency:

metrics:
- name: latency
  templateRef:
    name: latency
    namespace: istio-system
  thresholdRange:
    max: 500
  interval: 1m