NATS Streaming Clustering Helm Chart

Sets up a NATS Streaming server cluster with Raft based replication.

Getting started

This chart relies on an already available NATS Service to which the NATS Streaming nodes that will form a clusters can connect to. You can install the NATS Operator and then use it to create a NATS cluster via the following:

$ kubectl apply -f https://raw.githubusercontent.com/nats-io/nats-operator/master/example/deployment-rbac.yaml
$ kubectl apply -f https://raw.githubusercontent.com/nats-io/nats-operator/master/example/example-nats-cluster.yaml

This will create a NATS cluster on the nats-io namespace. Then, to install a NATS Streaming cluster the URL to the NATS cluster can be specified as follows (using my-release for a name label for the cluster):

$ git clone https://github.com/wallyqs/nats-streaming-cluster-chart nats-streaming-cluster
$ helm install nats-streaming -n my-release --set natsUrl=nats://nats.nats-io.svc.cluster.local:4222

This will create 3 follower nodes plus an extra Pod which is configured to be in bootstrapping mode, which will start as the leader of the Raft group as soon as it joins.

$ kubectl get pods --namespace default -l "app=nats-streaming,release=my-release"
NAME                                          READY     STATUS    RESTARTS   AGE
my-release-nats-streaming-0           1/1       Running   0          30s
my-release-nats-streaming-1           1/1       Running   0          23s
my-release-nats-streaming-2           1/1       Running   0          17s

Note that in case the bootstrapping Pod fails then it will not be recreated and instead one of the extra follower Pods will take over the leadership. The follower Pods are part of a Deployment so those in case of failure they will be recreated.

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

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

Configuration

Parameter	Description	Default
global.imageRegistry	Global Docker image registry	nil
image.registry	NATS Streaming image registry	docker.io
image.repository	NATS Streaming Image name	nats-streaming
image.tag	NATS Streaming Image tag	{VERSION}
image.pullPolicy	Image pull policy	IfNotPresent
image.pullSecrets	Specify image pull secrets	nil
auth.enabled	Switch to enable/disable client authentication	true
auth.user	Client authentication user	nats_cluster
auth.password	Client authentication password	random alhpanumeric string (10)
auth.token	Client authentication token	nil
auth.secretName	Client authentication secret name	nil
auth.secretKey	Client authentication secret key	nil
clusterID	NATS Streaming Cluster Name ID	"test-cluster"
natsSvc	External NATS Server URL	"nats://username:password@nats:4222"
maxChannels	Max # of channels	100
maxSubs	Max # of subscriptions per channel	1000
maxMsgs	Max # of messages per channel	"1000000"
maxBytes	Max messages total size per channel	900mb
maxAge	Max duration a message can be stored	"0s" (unlimited)
maxMsgs	Max # of messages per channel	1000000
debug	Enable debugging	false
trace	Enable detailed tracing	false
replicaCount	Number of NATS Streaming nodes	3
securityContext.enabled	Enable security context	true
securityContext.fsGroup	Group ID for the container	1001
securityContext.runAsUser	User ID for the container	1001
statefulset.updateStrategy	Statefulsets Update strategy	RollingUpdate
statefulset.rollingUpdatePartition	Partition for Rolling Update strategy	nil
podLabels	Additional labels to be added to pods	{}
podAnnotations	Annotations to be added to pods	{}
nodeSelector	Node labels for pod assignment	nil
schedulerName	Name of an alternate	nil
antiAffinity	Anti-affinity for pod assignment	soft
tolerations	Toleration labels for pod assignment	nil
resources	CPU/Memory resource requests/limits	{}
livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	30
livenessProbe.periodSeconds	How often to perform the probe	10
livenessProbe.timeoutSeconds	When the probe times out	5
livenessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
livenessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	5
readinessProbe.periodSeconds	How often to perform the probe	10
readinessProbe.timeoutSeconds	When the probe times out	5
readinessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
readinessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
monitoring.service.type	Kubernetes Service type (NATS Streaming monitoring)	ClusterIP
monitoring.service.port	NATS Streaming monitoring port	8222
monitoring.service.nodePort	Port to bind to for NodePort service type (NATS Streaming monitoring)	nil
monitoring.service.annotations	Annotations for NATS Streaming monitoring service	{}
monitoring.service.loadBalancerIP	loadBalancerIP if NATS Streaming monitoring service type is LoadBalancer	nil
networkPolicy.enabled	Enable NetworkPolicy	false
sidecars	Attach additional containers to the pod.	nil

File Specific Persistence Configuration

Parameter	Description	Default
persistence.file.compactEnabled	Enable compaction	true
persistence.file.bufferSize	File buffer size (in bytes)	"2097152" (2MB)
persistence.file.crc	Enable file CRC-32 checksum	true
persistence.file.sync	Enable File.Sync on Flush	true
persistence.file.fdsLimit	Max File Descriptor limit (approx)	0 (unlimited)

Additional configuration parameters not typically used may be found in values.yaml.