bitnamicharts/nats repository overview

⁠Bitnami Secure Images Helm chart 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

⁠ Introduction

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

⁠ Before you begin

• Kubernetes 1.23+
• Helm 3.8.0+
• PV provisioner support in the underlying infrastructure

⁠ Installing the chart

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

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

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

⁠ Configuration and installation details

This section describes resource settings, credentials, FIPS, Gateway API, Ingress, backup, metrics, TLS, and other options.

⁠ 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 resourcesPreset is discouraged as it may not fully adapt to your specific needs. Find more information on container resource management in the official Kubernetes documentation⁠.

⁠ Update credentials

The Bitnami NATS chart, when upgrading, reuses the secret previously rendered by the chart or the one specified in existingSecret. To update credentials, use one of the following:

• Run helm upgrade specifying new credentials using auth.token or auth.credentials parameters
• Run helm upgrade specifying a new secret in existingSecret

⁠ FIPS parameters

The FIPS parameters only have effect if you are using images from the Bitnami Secure Images catalog⁠.

For more information on this new support, please refer to the FIPS Compliance section⁠.

⁠ Gateway API

This chart provides support for exposing NATS using the Gateway API⁠ and its HTTPRoute resource. If you have a Gateway controller installed on your cluster, such as APISIX, Contour, Envoy Gateway, NGINX Gateway Fabric or Kong Ingress Controller you can utilize the Gateway controller to serve your application. To enable Gateway API integration, set httpRoute.enabled to true. The Gateway to be used can be customized by setting the httpRoute.parentRefs parameter. By default, it will reference a Gateway named gateway in the same namespace as the release.

You can specify the list of hostnames to be mapped to the deployment using the httpRoute.hostnames parameter. Additionally, you can customize the rules used to route the traffic to the service by modifying the httpRoute.matches and httpRoute.filters parameters or adding new rules using the httpRoute.extraRules parameter.

⁠ Ingress

This chart provides support for Ingress resources. If you have an ingress controller installed on your cluster, such as NGINX Ingress Controller or Contour you can utilize the ingress controller to serve your application. To enable Ingress integration, set ingress.enabled to true.

The most common scenario is to have one host name mapped to the deployment. In this case, the ingress.hostname property can be used to set the host name. The ingress.tls parameter can be used to add the TLS configuration for this host.

However, it is also possible to have more than one host. To facilitate this, the ingress.extraHosts parameter (if available) can be set with the host names specified as an array. The ingress.extraTLS parameter (if available) can also be used to add the TLS configuration for extra hosts.

Adding the TLS parameter (where available) will cause the chart to generate HTTPS URLs, and the application will be available on port 443. The actual TLS secrets do not have to be generated by this chart. However, if TLS is enabled, the Ingress record will not work until the TLS secret exists.

Learn more about Ingress controllers⁠.

⁠ Backup and restore

To back up and restore Helm chart deployments on Kubernetes, you need to back up the persistent volumes from the source deployment and attach them to a new deployment using Velero⁠, a Kubernetes backup/restore tool. Find the instructions for using Velero in this guide⁠.

⁠ Prometheus metrics

This chart can be integrated with Prometheus by setting metrics.enabled to true. This will deploy a sidecar container with prometheus-nats-exporter⁠ in all pods and a metrics service, which can be configured under the metrics.service section. This metrics service will have the necessary annotations to be automatically scraped by Prometheus.

⁠Prometheus requirements

It is necessary to have a working installation of Prometheus or Prometheus Operator for the integration to work. Install the Bitnami Prometheus helm chart⁠ or the Bitnami Kube Prometheus helm chart⁠ to easily have a working Prometheus in your cluster.

⁠Integration with Prometheus Operator

The chart can deploy ServiceMonitor objects for integration with Prometheus Operator installations. To do so, set the value metrics.serviceMonitor.enabled=true. Ensure that the Prometheus Operator CustomResourceDefinitions are installed in the cluster or it will fail with the following error:

no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"

Install the Bitnami Kube Prometheus helm chart⁠ for having the necessary CRDs and the Prometheus Operator.

⁠ Securing traffic using TLS

NATS can encrypt communications by setting tls.enabled=true.

It is necessary to create a secret containing the TLS certificates and pass it to the chart using the tls.existingCASecret, tls.server.existingSecret and tls.client.existingSecret parameters. Every secret should contain a tls.crt and tls.key keys including the certificate and key files respectively.

You can manually create the required TLS certificates or relying on the chart auto-generation capabilities. The chart supports two different ways to auto-generate the required certificates:

• Using Helm capabilities. Enable this feature by setting tls.autoGenerated.enabled to true and tls.autoGenerated.engine to helm.
• Relying on CertManager (please note it's required to have CertManager installed in your K8s cluster). Enable this feature by setting tls.autoGenerated.enabled to true and tls.autoGenerated.engine to cert-manager. Please note it's supported to use an existing Issuer/ClusterIssuer for issuing the TLS certificates by setting the tls.autoGenerated.certManager.existingIssuer and tls.autoGenerated.certManager.existingIssuerKind parameters.

⁠ 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

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 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

The following subsections list global, common, and component-specific parameters.

⁠ Global parameters

⁠ Common parameters

⁠ NATS parameters

Note: the README for this chart is longer than the DockerHub length limit of 25000, so it has been trimmed. The full README can be found at https://techdocs.broadcom.com/us/en/vmware-tanzu/bitnami-secure-images/bitnami-secure-images/services/bsi-app-doc/apps-charts-nats-index.html⁠