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.defaultStorageClass Global default StorageClass for Persistent Volume(s) ""
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.livenessProbe.enabled Enable livenessProbe true
metrics.livenessProbe.initialDelaySeconds Initial delay seconds for livenessProbe 15
metrics.livenessProbe.timeoutSeconds Timeout seconds for livenessProbe 5
metrics.readinessProbe.enabled Enable readinessProbe true
metrics.readinessProbe.initialDelaySeconds Initial delay seconds for readinessProbe 5
metrics.readinessProbe.timeoutSeconds Timeout seconds for readinessProbe 1
metrics.customLivenessProbe Override default liveness probe {}
metrics.customReadinessProbe Override default readiness probe {}
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 {}
persistentVolumeClaimRetentionPolicy.enabled Enable Persistent volume retention policy for NATS statefulset false
persistentVolumeClaimRetentionPolicy.whenScaled Volume retention behavior when the replica count of the StatefulSet is reduced Retain
persistentVolumeClaimRetentionPolicy.whenDeleted Volume retention behavior that applies when the StatefulSet is deleted Retain

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.

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