bitnamicharts/scylladb repository overview

⁠Bitnami Secure Images Helm chart for ScyllaDB

ScyllaDB is an open-source, distributed NoSQL wide-column data store. Written in C++, it is designed for high throughput and low latency, compatible with Apache Cassandra.

Overview of ScyllaDB⁠

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/scylladb

⁠ Introduction

This chart bootstraps an ScyllaDB⁠ 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/scylladb

These commands deploy one node with ScyllaDB 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 credentials, configuration, and other installation 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

Bitnami charts configure credentials at first boot. Any further change in the secrets or credentials require manual intervention. Follow these instructions:

• Update the user password following the upstream documentation⁠
• Update the password secret with the new values (replace the SECRET_NAME and PASSWORD placeholders)

kubectl create secret generic SECRET_NAME --from-literal=scylladb-password=PASSWORD --dry-run -o yaml | kubectl apply -f -

⁠ Prometheus metrics

This chart can be integrated with Prometheus by setting metrics.enabled to true. This will expose ScyllaDB native Prometheus in all pods and via the ScyllaDB service. This 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.

⁠ 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.

⁠ Securing Traffic using TLS

This chart supports TLS between client and server and between nodes, as explained below:

• For internode cluster encryption, set the tls.internodeEncryption chart parameter to a value different from none. Available values are all, dc or rack.
• For client-server encryption, set the tls.clientEncryption chart parameter to true.

In both cases, it is also necessary to create a secret containing the certificate. This secret is to be passed to the chart via the tls.existingSecret parameter at deployment-time, as shown below:

tls.internodeEncryption=all
tls.clientEncryption=true
tls.existingSecret=my-existing-stores

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.

⁠ Initialize the database

The ScyllaDB⁠ image supports the use of custom scripts to initialize a fresh instance. This may be done by creating a Kubernetes ConfigMap that includes the necessary .sh or .cql scripts and passing this ConfigMap to the chart via the initDBConfigMap parameter.

⁠ Use a custom configuration file

This chart also supports mounting custom configuration file(s) for ScyllaDB. This is achieved by setting the existingConfiguration parameter with the name of a ConfigMap that includes the custom configuration file(s). Here is an example of deploying the chart with a custom configuration file stored in a ConfigMap named scylladb-configuration:

existingConfiguration=scylladb-configuration

⁠ Set pod affinity

This chart allows you to set custom pod affinity using the XXX.affinity parameter(s). 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 XXX.podAffinityPreset, XXX.podAntiAffinityPreset, or XXX.nodeAffinityPreset parameters.

⁠ 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.

⁠ 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.

⁠ Persistence

The Bitnami ScyllaDB⁠ image stores the ScyllaDB data at the /bitnami/scylladb path of the container.

Persistent Volume Claims are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube. See the Parameters⁠ section to configure the PVC or to disable persistence.

If you encounter errors when working with persistent volumes, refer to our troubleshooting guide for persistent volumes⁠.

⁠ Adjust permissions of persistent volume mountpoint

As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it. There are two approaches to achieve this:

• Use Kubernetes SecurityContexts by setting the podSecurityContext.enabled and containerSecurityContext.enabled to true. This option is enabled by default in the chart. However, this feature does not work in all Kubernetes distributions.
• Use an init container to change the ownership of the volume before mounting it in the final destination. Enable this container by setting the volumePermissions.enabled parameter to true.

⁠ Parameters

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

⁠ Global parameters

⁠ Common parameters

⁠ Scylladb parameters

⁠ Statefulset 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-scylladb-index.html⁠