Bitnami package for NATS

NATS is an open source, lightweight and high-performance messaging system. It is ideal for distributed systems and supports modern cloud architectures and pub-sub, request-reply and queuing models.

Overview of NATS

Trademarks: This software listing is packaged by Bitnami. The respective trademarks mentioned in the offering are owned by the respective companies, and use of them does not imply any affiliation or endorsement.

TL;DR

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/nats

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository.

Introduction

This chart bootstraps a NATS deployment on a Kubernetes cluster using the Helm package manager.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters.

Prerequisites

• Kubernetes 1.23+
• Helm 3.8.0+

Installing the Chart

To install the chart with the release name my-release:

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/nats

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository. For example, in the case of Bitnami, you need to use REGISTRY_NAME=registry-1.docker.io and REPOSITORY_NAME=bitnamicharts.

The command deploys NATS on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.

Tip: List all releases using helm list

Configuration and installation details

Resource requests and limits

Bitnami charts allow setting resource requests and limits for all containers inside the chart deployment. These are inside the resources value (check parameter table). Setting requests is essential for production workloads and these should be adapted to your specific use case.

To make this process easier, the chart contains the resourcesPreset values, which automatically sets the resources section according to different presets. Check these presets in the bitnami/common chart. However, in production workloads using resourcePreset is discouraged as it may not fully adapt to your specific needs. Find more information on container resource management in the official Kubernetes documentation.

Rolling vs Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Add extra environment variables

In case you want to add extra environment variables (useful for advanced operations like custom init scripts), you can use the extraEnvVars property.

extraEnvVars:
  - name: LOG_LEVEL
    value: DEBUG

Alternatively, you can use a ConfigMap or a Secret with the environment variables. To do so, use the extraEnvVarsCM or the extraEnvVarsSecret values.

Use Sidecars and Init Containers

If additional containers are needed in the same pod (such as additional metrics or logging exporters), they can be defined using the sidecars config parameter.

sidecars:
- name: your-image-name
  image: your-image
  imagePullPolicy: Always
  ports:
  - name: portname
    containerPort: 1234

If these sidecars export extra ports, extra port definitions can be added using the service.extraPorts parameter (where available), as shown in the example below:

service:
  extraPorts:
  - name: extraPort
    port: 11311
    targetPort: 11311

NOTE: This Helm chart already includes sidecar containers for the Prometheus exporters (where applicable). These can be activated by adding the --enable-metrics=true parameter at deployment time. The sidecars parameter should therefore only be used for any extra sidecar containers.

If additional init containers are needed in the same pod, they can be defined using the initContainers parameter. Here is an example:

initContainers:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
        containerPort: 1234

Learn more about sidecar containers and init containers.

Deploy extra resources

There are cases where you may want to deploy extra objects, such a ConfigMap containing your app’s configuration or some extra deployment with a micro service used by your app. For covering this case, the chart allows adding the full specification of other objects using the extraDeploy parameter.

Set Pod affinity

This chart allows you to set custom Pod affinity using the affinity parameter. Find more information about Pod affinity in the Kubernetes documentation.

As an alternative, you can use of the preset configurations for pod affinity, pod anti-affinity, and node affinity available at the bitnami/common chart. To do so, set the podAffinityPreset, podAntiAffinityPreset, or nodeAffinityPreset parameters.

Parameters

Global parameters

Name	Description	Value
global.imageRegistry	Global Docker image registry	""
global.imagePullSecrets	Global Docker registry secret names as an array	[]
global.compatibility.openshift.adaptSecurityContext	Adapt the securityContext sections of the deployment to make them compatible with Openshift restricted-v2 SCC: remove runAsUser, runAsGroup and fsGroup and let the platform use their allowed default IDs. Possible values: auto (apply if the detected running cluster is Openshift), force (perform the adaptation always), disabled (do not perform adaptation)	auto

Common parameters

Name	Description	Value
kubeVersion	Force target Kubernetes version (using Helm capabilities if not set)	""
nameOverride	String to partially override common.names.fullname template (will maintain the release name)	""
fullnameOverride	String to fully override common.names.fullname template	""
commonLabels	Add labels to all the deployed resources	{}
commonAnnotations	Add annotations to all the deployed resources	{}
clusterDomain	Kubernetes Cluster Domain	cluster.local
extraDeploy	Array of extra objects to deploy with the release	[]
diagnosticMode.enabled	Enable diagnostic mode (all probes will be disabled and the command will be overridden)	false
diagnosticMode.command	Command to override all containers in the deployment	["sleep"]
diagnosticMode.args	Args to override all containers in the deployment	["infinity"]

NATS parameters

Name	Description	Value
image.registry	NATS image registry	REGISTRY_NAME
image.repository	NATS image repository	REPOSITORY_NAME/nats
image.digest	NATS image digest in the way sha256:aa…. Please note this parameter, if set, will override the tag	""
image.pullPolicy	NATS image pull policy	IfNotPresent
image.pullSecrets	NATS image pull secrets	[]
image.debug	Enable NATS image debug mode	false
auth.enabled	Switch to enable/disable client authentication	true
auth.user	Client authentication user	nats_client
auth.password	Client authentication password	""
auth.token	Client authentication token	""
auth.timeout	Client authentication timeout (seconds)	1
auth.usersCredentials	Client authentication users credentials collection	[]
auth.noAuthUser	Client authentication username from auth.usersCredentials map to be used when no credentials provided	""
cluster.name	Cluster name	nats
cluster.connectRetries	Configure number of connect retries for implicit routes, otherwise leave blank	""
cluster.auth.enabled	Switch to enable/disable cluster authentication	true
cluster.auth.user	Cluster authentication user	nats_cluster
cluster.auth.password	Cluster authentication password	""
jetstream.enabled	Switch to enable/disable JetStream	false
jetstream.maxMemory	Max memory usage for JetStream	1G
debug.enabled	Switch to enable/disable debug on logging	false
debug.trace	Switch to enable/disable trace debug level on logging	false
debug.logtime	Switch to enable/disable logtime on logging	false
maxConnections	Max. number of client connections	""
maxControlLine	Max. protocol control line	""
maxPayload	Max. payload	""
writeDeadline	Duration the server can block on a socket write to a client	""
natsFilename	Filename used by several NATS files (binary, configuration file, and pid file)	nats-server
configuration	Specify content for NATS configuration file (generated based on other parameters otherwise)	""
existingSecret	The name of an existing Secret with your custom configuration for NATS	""
command	Override default container command (useful when using custom images)	[]
args	Override default container args (useful when using custom images)	[]
extraEnvVars	Extra environment variables to be set on NATS container	[]
extraEnvVarsCM	ConfigMap with extra environment variables	""
extraEnvVarsSecret	Secret with extra environment variables	""

NATS deployment/statefulset parameters

Name	Description	Value
resourceType	NATS cluster resource type under Kubernetes. Allowed values: statefulset (default) or deployment	statefulset
replicaCount	Number of NATS nodes	1
schedulerName	Use an alternate scheduler, e.g. “stork”.	""
priorityClassName	Name of pod priority class	""
updateStrategy.type	StrategyType. Can be set to RollingUpdate or OnDelete	RollingUpdate
containerPorts.client	NATS client container port	4222
containerPorts.cluster	NATS cluster container port	6222
containerPorts.monitoring	NATS monitoring container port	8222
podSecurityContext.enabled	Enabled NATS pods’ Security Context	true
podSecurityContext.fsGroupChangePolicy	Set filesystem group change policy	Always
podSecurityContext.sysctls	Set kernel settings using the sysctl interface	[]
podSecurityContext.supplementalGroups	Set filesystem extra groups	[]
podSecurityContext.fsGroup	Set NATS pod’s Security Context fsGroup	1001
containerSecurityContext.enabled	Enabled containers’ Security Context	true
containerSecurityContext.seLinuxOptions	Set SELinux options in container	nil
containerSecurityContext.runAsUser	Set containers’ Security Context runAsUser	1001
containerSecurityContext.runAsGroup	Set containers’ Security Context runAsGroup	1001
containerSecurityContext.runAsNonRoot	Set container’s Security Context runAsNonRoot	true
containerSecurityContext.privileged	Set container’s Security Context privileged	false
containerSecurityContext.readOnlyRootFilesystem	Set container’s Security Context readOnlyRootFilesystem	true
containerSecurityContext.allowPrivilegeEscalation	Set container’s Security Context allowPrivilegeEscalation	false
containerSecurityContext.capabilities.drop	List of capabilities to be dropped	["ALL"]
containerSecurityContext.seccompProfile.type	Set container’s Security Context seccomp profile	RuntimeDefault
resourcesPreset	Set container resources according to one common preset (allowed values: none, nano, micro, small, medium, large, xlarge, 2xlarge). This is ignored if resources is set (resources is recommended for production).	nano
resources	Set container requests and limits for different resources like CPU or memory (essential for production workloads)	{}
livenessProbe.enabled	Enable livenessProbe	true
livenessProbe.initialDelaySeconds	Initial delay seconds for livenessProbe	30
livenessProbe.periodSeconds	Period seconds for livenessProbe	10
livenessProbe.timeoutSeconds	Timeout seconds for livenessProbe	5
livenessProbe.failureThreshold	Failure threshold for livenessProbe	6
livenessProbe.successThreshold	Success threshold for livenessProbe	1
readinessProbe.enabled	Enable readinessProbe	true
readinessProbe.initialDelaySeconds	Initial delay seconds for readinessProbe	5
readinessProbe.periodSeconds	Period seconds for readinessProbe	10
readinessProbe.timeoutSeconds	Timeout seconds for readinessProbe	5
readinessProbe.failureThreshold	Failure threshold for readinessProbe	6
readinessProbe.successThreshold	Success threshold for readinessProbe	1
startupProbe.enabled	Enable startupProbe on NATS containers	false
startupProbe.initialDelaySeconds	Initial delay seconds for startupProbe	5
startupProbe.periodSeconds	Period seconds for startupProbe	10
startupProbe.timeoutSeconds	Timeout seconds for startupProbe	5
startupProbe.failureThreshold	Failure threshold for startupProbe	6
startupProbe.successThreshold	Success threshold for startupProbe	1
customLivenessProbe	Override default liveness probe	{}
customReadinessProbe	Override default readiness probe	{}
customStartupProbe	Custom startupProbe that overrides the default one	{}
automountServiceAccountToken	Mount Service Account token in pod	false
hostAliases	Deployment pod host aliases	[]
podLabels	Extra labels for NATS pods	{}
podAnnotations	Annotations for NATS pods	{}
podAffinityPreset	Pod affinity preset. Ignored if affinity is set. Allowed values: soft or hard	""
podAntiAffinityPreset	Pod anti-affinity preset. Ignored if affinity is set. Allowed values: soft or hard	soft
nodeAffinityPreset.type	Node affinity preset type. Ignored if affinity is set. Allowed values: soft or hard	""
nodeAffinityPreset.key	Node label key to match. Ignored if affinity is set.	""
nodeAffinityPreset.values	Node label values to match. Ignored if affinity is set.	[]
affinity	Affinity for pod assignment. Evaluated as a template.	{}
nodeSelector	Node labels for pod assignment. Evaluated as a template.	{}
tolerations	Tolerations for pod assignment. Evaluated as a template.	[]
topologySpreadConstraints	Topology Spread Constraints for NATS pods assignment spread across your cluster among failure-domains	[]
lifecycleHooks	for the NATS container(s) to automate configuration before or after startup	{}
extraVolumes	Optionally specify extra list of additional volumes for NATS pods	[]
extraVolumeMounts	Optionally specify extra list of additional volumeMounts for NATS container(s)	[]
initContainers	Add additional init containers to the NATS pods	[]
sidecars	Add additional sidecar containers to the NATS pods	[]
serviceAccount.create	Enable creation of ServiceAccount for NATS pod	true
serviceAccount.name	The name of the ServiceAccount to use.	""
serviceAccount.automountServiceAccountToken	Allows auto mount of ServiceAccountToken on the serviceAccount created	false
serviceAccount.annotations	Additional custom annotations for the ServiceAccount	{}

Traffic Exposure parameters

Name	Description	Value
service.type	NATS service type	ClusterIP
service.ports.client	NATS client service port	4222
service.ports.cluster	NATS cluster service port	6222
service.ports.monitoring	NATS monitoring service port	8222
service.nodePorts.client	Node port for clients	""
service.nodePorts.cluster	Node port for clustering	""
service.nodePorts.monitoring	Node port for monitoring	""
service.sessionAffinity	Control where client requests go, to the same pod or round-robin	None
service.sessionAffinityConfig	Additional settings for the sessionAffinity	{}
service.clusterIP	NATS service Cluster IP	""
service.loadBalancerIP	NATS service Load Balancer IP	""
service.loadBalancerSourceRanges	NATS service Load Balancer sources	[]
service.externalTrafficPolicy	NATS service external traffic policy	Cluster
service.annotations	Additional custom annotations for NATS service	{}
service.extraPorts	Extra ports to expose in the NATS service (normally used with the sidecar value)	[]
service.headless.annotations	Annotations for the headless service.	{}
ingress.enabled	Set to true to enable ingress record generation	false
ingress.pathType	Ingress Path type	ImplementationSpecific
ingress.apiVersion	Override API Version (automatically detected if not set)	""
ingress.hostname	When the ingress is enabled, a host pointing to this will be created	nats.local
ingress.path	The Path to NATS. You may need to set this to ‘/*’ in order to use this with ALB ingress controllers.	/
ingress.ingressClassName	IngressClass that will be be used to implement the Ingress (Kubernetes 1.18+)	""
ingress.annotations	Additional annotations for the Ingress resource. To enable certificate autogeneration, place here your cert-manager annotations.	{}
ingress.tls	Enable TLS configuration for the host defined at ingress.hostname parameter	false
ingress.selfSigned	Create a TLS secret for this ingress record using self-signed certificates generated by Helm	false
ingress.extraHosts	The list of additional hostnames to be covered with this ingress record.	[]
ingress.extraPaths	Any additional arbitrary paths that may need to be added to the ingress under the main host.	[]
ingress.extraTls	The tls configuration for additional hostnames to be covered with this ingress record.	[]
ingress.secrets	If you’re providing your own certificates, please use this to add the certificates as secrets	[]
ingress.extraRules	Additional rules to be covered with this ingress record	[]
networkPolicy.enabled	Enable creation of NetworkPolicy resources	true
networkPolicy.allowExternal	The Policy model to apply	true
networkPolicy.allowExternalEgress	Allow the pod to access any range of port and all destinations.	true
networkPolicy.extraIngress	Add extra ingress rules to the NetworkPolicy	[]
networkPolicy.extraEgress	Add extra ingress rules to the NetworkPolicy	[]
networkPolicy.ingressNSMatchLabels	Labels to match to allow traffic from other namespaces	{}
networkPolicy.ingressNSPodMatchLabels	Pod labels to match to allow traffic from other namespaces	{}

Metrics parameters

Name	Description	Value
metrics.enabled	Enable Prometheus metrics via exporter side-car	false
metrics.image.registry	Prometheus metrics exporter image registry	REGISTRY_NAME
metrics.image.repository	Prometheus metrics exporter image repository	REPOSITORY_NAME/nats-exporter
metrics.image.digest	NATS Exporter image digest in the way sha256:aa…. Please note this parameter, if set, will override the tag	""
metrics.image.pullPolicy	Prometheus metrics image pull policy	IfNotPresent
metrics.image.pullSecrets	Prometheus metrics image pull secrets	[]
metrics.resourcesPreset	Set container resources according to one common preset (allowed values: none, nano, micro, small, medium, large, xlarge, 2xlarge). This is ignored if metrics.resources is set (metrics.resources is recommended for production).	nano
metrics.resources	Set container requests and limits for different resources like CPU or memory (essential for production workloads)	{}
metrics.containerPorts.http	Prometheus metrics exporter port	7777
metrics.flags	Flags to be passed to Prometheus metrics	[]
metrics.service.type	Kubernetes service type (ClusterIP, NodePort or LoadBalancer)	ClusterIP
metrics.service.port	Prometheus metrics service port	7777
metrics.service.loadBalancerIP	Use serviceLoadBalancerIP to request a specific static IP, otherwise leave blank	""
metrics.service.annotations	Annotations for Prometheus metrics service	{}
metrics.service.labels	Labels for Prometheus metrics service	{}
metrics.serviceMonitor.enabled	Specify if a ServiceMonitor will be deployed for Prometheus Operator	false
metrics.serviceMonitor.namespace	Namespace in which Prometheus is running	monitoring
metrics.serviceMonitor.labels	Extra labels for the ServiceMonitor	{}
metrics.serviceMonitor.jobLabel	The name of the label on the target service to use as the job name in Prometheus	""
metrics.serviceMonitor.interval	How frequently to scrape metrics	""
metrics.serviceMonitor.scrapeTimeout	Timeout after which the scrape is ended	""
metrics.serviceMonitor.metricRelabelings	Specify additional relabeling of metrics	[]
metrics.serviceMonitor.relabelings	Specify general relabeling	[]
metrics.serviceMonitor.selector	Prometheus instance selector labels	{}

Persistence parameters

Name	Description	Value
persistence.enabled	Enable NATS data persistence using PVC(s)	false
persistence.storageClass	PVC Storage Class for NATS data volume	""
persistence.accessModes	PVC Access modes	["ReadWriteOnce"]
persistence.size	PVC Storage Request for NATS data volume	8Gi
persistence.annotations	Annotations for the PVC	{}
persistence.selector	Selector to match an existing Persistent Volume for NATS’s data PVC	{}

Other parameters

Name	Description	Value
pdb.create	Enable/disable a Pod Disruption Budget creation	true
pdb.minAvailable	Minimum number/percentage of pods that should remain scheduled	""
pdb.maxUnavailable	Maximum number/percentage of pods that may be made unavailable	""

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

helm install my-release \
  --set auth.enabled=true,auth.user=my-user,auth.password=T0pS3cr3t \
    oci://REGISTRY_NAME/REPOSITORY_NAME/nats

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository. For example, in the case of Bitnami, you need to use REGISTRY_NAME=registry-1.docker.io and REPOSITORY_NAME=bitnamicharts.

The above command enables NATS client authentication with my-user as user and T0pS3cr3t as password credentials.

NOTE: Once this chart is deployed, it is not possible to change the application’s access credentials, such as usernames or passwords, using Helm. To change these application credentials after deployment, delete any persistent volumes (PVs) used by the chart and re-deploy it, or use the application’s built-in administrative tools if available.

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

helm install my-release -f values.yaml oci://REGISTRY_NAME/REPOSITORY_NAME/nats

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository. For example, in the case of Bitnami, you need to use REGISTRY_NAME=registry-1.docker.io and REPOSITORY_NAME=bitnamicharts. Tip: You can use the default values.yaml

Troubleshooting

Find more information about how to deal with common errors related to Bitnami’s Helm charts in this troubleshooting guide.

Upgrading

To 8.0.0

This major bump changes the following security defaults:

• runAsGroup is changed from 0 to 1001
• readOnlyRootFilesystem is set to true
• resourcesPreset is changed from none to the minimum size working in our test suites (NOTE: resourcesPreset is not meant for production usage, but resources adapted to your use case).
• global.compatibility.openshift.adaptSecurityContext is changed from disabled to auto.

This could potentially break any customization or init scripts used in your deployment. If this is the case, change the default values to the previous ones.

To 7.0.0

This new version updates the NATS image to a new version that has support to configure NATS based on bash logic, although this chart overwrites the configuration file so that shouldn’t affect the functionality. It also adds several standardizations that were missing in the chart:

• Add missing parameters such as existingSecret, containerPorts.*, startupProbe.* or lifecycleHooks.
• Add missing parameters to extend the services such as service.extraPorts or service.sessionAffinity.
• Add missing parameters to customize the ServiceMonitor for Prometheus Operator.

Other important changes:

• The NATS configuration file is no longer retrieved from a ConfigMap but a Secret instead.
• Regroup the client, cluster and monitoring service into a single service that exposes every port.

Consequences:

• Backwards compatibility is not guaranteed.

To 6.0.0

• Some parameters were renamed or disappeared in favor of new ones on this major version. For instance:
  • securityContext.* is deprecated in favor of podSecurityContext and containerSecurityContext.
• Ingress configuration was adapted to follow the Helm charts best practices.
• Chart labels were also adapted to follow the Helm charts standard labels.
• This version also introduces bitnami/common, a library chart as a dependency. More documentation about this new utility could be found here. Please, make sure that you have updated the chart dependencies before executing any upgrade.

Consequences:

• Backwards compatibility is not guaranteed.

To 5.0.0

On November 13, 2020, Helm v2 support formally ended. This major version is the result of the required changes applied to the Helm Chart to be able to incorporate the different features added in Helm v3 and to be consistent with the Helm project itself regarding the Helm v2 EOL.

Deploy chart with NATS version 1.x.x

NATS version 2.0.0 has renamed the server binary filename from gnatsd to nats-server. Therefore, the default values has been changed in the chart, however, it is still possible to use the chart to deploy NATS version 1.x.x using the natsFilename property.

helm install nats-v1 --set natsFilename=gnatsd --set image.tag=1.4.1 oci://REGISTRY_NAME/REPOSITORY_NAME/nats

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository. For example, in the case of Bitnami, you need to use REGISTRY_NAME=registry-1.docker.io and REPOSITORY_NAME=bitnamicharts.

To 1.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart’s deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is nats:

kubectl delete statefulset nats-nats --cascade=false

License

Copyright © 2024 Broadcom. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.