Flagger

Flagger is a progressive delivery tool that automates the release process for applications running on Kubernetes. It reduces the risk of introducing a new software version in production by gradually shifting traffic to the new version while measuring metrics and running conformance tests.

Flagger implements several deployment strategies (Canary releases, A/B testing, Blue/Green mirroring) and integrates with various Kubernetes ingress controllers, service mesh and monitoring solutions.

Flagger is a Cloud Native Computing Foundation project and part of Flux family of GitOps tools.

Prerequisites

• Kubernetes >= 1.19

Installing the Chart

Add Flagger Helm repository:

$ helm repo add flagger https://flagger.app

Install Flagger's custom resource definitions:

$ kubectl apply -f https://raw.githubusercontent.com/fluxcd/flagger/main/artifacts/flagger/crd.yaml

To install Flagger for Istio:

$ helm upgrade -i flagger flagger/flagger \
    --namespace=istio-system \
    --set meshProvider=istio \
    --set metricsServer=http://prometheus:9090

To install Flagger for Linkerd (requires Linkerd Viz extension):

# Note that linkerdAuthPolicy.create=true is only required for Linkerd 2.12 and
# later
$ helm upgrade -i flagger flagger/flagger \
    --namespace=flagger-system \
    --set meshProvider=linkerd \
    --set metricsServer=http://prometheus.linkerd-viz:9090 \
    --set linkerdAuthPolicy.create=true

To install Flagger for AWS App Mesh:

$ helm upgrade -i flagger flagger/flagger \
    --namespace=appmesh-system \
    --set meshProvider=appmesh:v1beta2 \
    --set metricsServer=http://appmesh-prometheus:9090

To install Flagger for Open Service Mesh (requires OSM to have been installed with Prometheus):

$ helm upgrade -i flagger flagger/flagger \
    --namespace=osm-system \
    --set meshProvider=osm \
    --set metricsServer=http://osm-prometheus.osm-system.svc:7070

To install Flagger for Kuma Service Mesh (requires Kuma to have been installed with Prometheus):

$ helm upgrade -i flagger flagger/flagger \
    --namespace=kuma-system \
    --set meshProvider=kuma \
    --set metricsServer=http://prometheus-server.kuma-metrics:80

To install Flagger and Prometheus for NGINX Ingress (requires controller metrics enabled):

$ helm upgrade -i flagger flagger/flagger \
    --namespace=ingress-nginx \
    --set meshProvider=nginx \
    --set prometheus.install=true

To install Flagger and Prometheus for Gloo (no longer requires Gloo discovery):

$ helm upgrade -i flagger flagger/flagger \
    --namespace=gloo-system \
    --set meshProvider=gloo \
    --set prometheus.install=true

To install Flagger and Prometheus for Contour:

$ helm upgrade -i flagger flagger/flagger \
    --namespace=projectcontour \
    --set meshProvider=contour \
    --set ingressClass=contour \
    --set prometheus.install=true

To install Flagger and Prometheus for Traefik:

$ helm upgrade -i flagger flagger/flagger \
    --namespace=traefik \
    --set prometheus.install=true \
    --set meshProvider=traefik

The configuration section lists the parameters that can be configured during installation.

Uninstalling the Chart

To uninstall/delete the flagger deployment:

$ helm delete flagger

The command removes all the Kubernetes components associated with the chart and deletes the release.

Configuration

The following tables lists the configurable parameters of the Flagger chart and their default values.

Parameter	Description	Default
image.repository	Image repository	ghcr.io/fluxcd/flagger
image.tag	Image tag	<VERSION>
image.pullPolicy	Image pull policy	IfNotPresent
logLevel	Log level	info
metricsServer	Prometheus URL, used when prometheus.install is false	http://prometheus.istio-system:9090
prometheus.install	If true, installs Prometheus configured to scrape all pods in the custer	false
prometheus.retention	Prometheus data retention	2h
selectorLabels	List of labels that Flagger uses to create pod selectors	app,name,app.kubernetes.io/name
serviceMonitor.enabled	If true, creates service and serviceMonitor for monitoring Flagger metrics	false
serviceMonitor.honorLabels	If true, label conflicts are resolved by keeping label values from the scraped data and ignoring the conflicting server-side labels	false
serviceMonitor.namespace	Namespace Servicemonitor is installed in	the same namespace
serviceMonitor.labels	labels for the ServiceMonitor passed to Prometheus Operator	{}
configTracking.enabled	If true, flagger will track changes in Secrets and ConfigMaps referenced in the target deployment	true
eventWebhook	If set, Flagger will publish events to the given webhook	None
slack.url	Slack incoming webhook	None
slack.proxyUrl	Slack proxy url	None
slack.channel	Slack channel	None
slack.user	Slack username	flagger
msteams.url	Microsoft Teams incoming webhook	None
msteams.proxyUrl	Microsoft Teams proxy url	None
clusterName	When specified, Flagger will add the cluster name to alerts	""
podMonitor.enabled	If true, create a PodMonitor for monitoring the metrics	false
podMonitor.namespace	Namespace where the PodMonitor is created	the same namespace
podMonitor.interval	Interval at which metrics should be scraped	15s
podMonitor.podMonitor	Additional labels to add to the PodMonitor	{}
podMonitor.honorLabels	If true, label conflicts are resolved by keeping label values from the scraped data and ignoring the conflicting server-side labels	false
leaderElection.enabled	If true, Flagger will run in HA mode	false
leaderElection.replicaCount	Number of replicas	1
serviceAccount.create	If true, Flagger will create service account	true
serviceAccount.name	The name of the service account to create or use. If not set and serviceAccount.create is true, a name is generated using the Flagger fullname	""
serviceAccount.annotations	Annotations for service account	{}
ingressAnnotationsPrefix	Annotations prefix for ingresses	custom.ingress.kubernetes.io
includeLabelPrefix	List of prefixes of labels that are copied when creating primary deployments or daemonsets. Use * to include all	""
rbac.create	If true, create and use RBAC resources	true
rbac.pspEnabled	If true, create and use a restricted pod security policy	false
crd.create	If true, create Flagger's CRDs (should be enabled for Helm v2 only)	false
resources.requests/cpu	Pod CPU request	10m
resources.requests/memory	Pod memory request	32Mi
resources.limits/cpu	Pod CPU limit	1000m
resources.limits/memory	Pod memory limit	512Mi
affinity	Node/pod affinities	prefer spread across hosts
nodeSelector	Node labels for pod assignment	{}
threadiness	Number of controller workers	2
tolerations	List of node taints to tolerate	[]
controlplane.kubeconfig.secretName	The name of the Kubernetes secret containing the service mesh control plane kubeconfig	None
controlplane.kubeconfig.key	The name of Kubernetes secret data key that contains the service mesh control plane kubeconfig	kubeconfig
ingressAnnotationsPrefix	Annotations prefix for NGINX ingresses	None
ingressClass	Ingress class used for annotating HTTPProxy objects, e.g. contour	None
podPriorityClassName	PriorityClass name for pod priority configuration	""
podDisruptionBudget.enabled	A PodDisruptionBudget will be created if true	false
podDisruptionBudget.minAvailable	The minimal number of available replicas that will be set in the PodDisruptionBudget	1
podDisruptionBudget.minAvailable	The minimal number of available replicas that will be set in the PodDisruptionBudget	1
noCrossNamespaceRefs	If true, cross namespace references to custom resources will be disabled	false
namespace	When specified, Flagger will restrict itself to watching Canary objects from that namespace	""

Specify each parameter using the --set key=value[,key=value] argument to helm upgrade. For example,

$ helm upgrade -i flagger flagger/flagger \
  --namespace flagger-system \
  --set slack.url=https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK \
  --set slack.channel=general

Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,

$ helm upgrade -i flagger flagger/flagger \
  --namespace istio-system \
  -f values.yaml

Tip: You can use the default values.yaml