bitnamicharts/kong repository overview

⁠Bitnami Secure Images Helm chart for Kong

Kong is an open source Microservice API gateway and platform designed for managing microservices requests of high-availability, fault-tolerance, and distributed systems.

Overview of Kong⁠

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/kong

⁠ Introduction

This chart bootstraps a kong⁠ deployment on a Kubernetes⁠ cluster using the Helm⁠ package manager. It also includes the kong-ingress-controller⁠ container for managing Ingress resources using Kong.

Extra functionalities beyond the Kong core are extended through plugins. Kong is built on top of reliable technologies like NGINX and provides an easy-to-use RESTful API to operate and configure the system.

⁠ 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/kong

These commands deploy kong 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.

⁠ 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.

⁠ Prometheus metrics

This chart can be integrated with Prometheus by setting metrics.enabled to true. This will enable Kong native prometheus port 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.

⁠ Database backend

The Bitnami Kong chart allows setting two database backends: PostgreSQL or Cassandra. For each option, there are two extra possibilities: deploy a sub-chart with the database installation or use an existing one. The list below details the different options (replace the placeholders specified between UNDERSCORES):

• Deploy the PostgreSQL sub-chart (default)

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

• Use an external PostgreSQL database

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/kong \
    --set postgresql.enabled=false \
    --set postgresql.external.host=_HOST_OF_YOUR_POSTGRESQL_INSTALLATION_ \
    --set postgresql.external.password=_PASSWORD_OF_YOUR_POSTGRESQL_INSTALLATION_ \
    --set postgresql.external.user=_USER_OF_YOUR_POSTGRESQL_INSTALLATION_

• Deploy the Cassandra sub-chart

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/kong \
    --set database=cassandra \
    --set postgresql.enabled=false \
    --set cassandra.enabled=true

• Use an existing Cassandra installation

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/kong \
    --set database=cassandra \
    --set postgresql.enabled=false \
    --set cassandra.enabled=false \
    --set cassandra.external.hosts[0]=_CONTACT_POINT_0_OF_YOUR_CASSANDRA_CLUSTER_ \
    --set cassandra.external.hosts[1]=_CONTACT_POINT_1_OF_YOUR_CASSANDRA_CLUSTER_ \
    ...
    --set cassandra.external.user=_USER_OF_YOUR_CASSANDRA_INSTALLATION_ \
    --set cassandra.external.password=_PASSWORD_OF_YOUR_CASSANDRA_INSTALLATION_

⁠ DB-less

Kong 1.1 added the capability to run Kong without a database, using only in-memory storage for entities: we call this DB-less mode. When running Kong DB-less, the configuration of entities is done in a second configuration file, in YAML or JSON, using declarative configuration (ref. Link⁠). As is said in step 4 of kong official docker installation⁠, just add the env variable "KONG_DATABASE=off".

⁠ 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.

⁠How to enable it

1. Set database value with any value other than "postgresql" or "cassandra". For example database: "off"
2. Use kong.extraEnvVars value to set the KONG_DATABASE environment variable:

kong.extraEnvVars:
- name: KONG_DATABASE
  value: "off"

⁠ Sidecars and Init Containers

If you have a need for additional containers to run within the same pod as Kong (e.g. an additional metrics or logging exporter), you can do so via the sidecars config parameter. Simply define your container according to the Kubernetes container spec.

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

Similarly, you can add extra init containers using the initContainers parameter.

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

⁠ Adding extra environment variables

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

kong:
  extraEnvVars:
    - name: KONG_LOG_LEVEL
      value: error

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

The Kong Ingress Controller and the Kong Migration job also allow this kind of configuration via the ingressController.extraEnvVars, ingressController.extraEnvVarsCM, ingressController.extraEnvVarsSecret, migration.extraEnvVars, migration.extraEnvVarsCM and migration.extraEnvVarsSecret values.

⁠ Using custom init scripts

For advanced operations, the Bitnami Kong charts allows using custom init scripts that will be mounted in /docker-entrypoint.init-db. You can use a ConfigMap or a Secret (in case of sensitive data) for mounting these extra scripts. Then use the kong.initScriptsCM and kong.initScriptsSecret values.

elasticsearch.hosts[0]=elasticsearch-host
elasticsearch.port=9200
initScriptsCM=special-scripts
initScriptsSecret=special-scripts-sensitive

⁠ Deploying extra resources

There are cases where you may want to deploy extra objects, such as KongPlugins, KongConsumers, amongst others. For covering this case, the chart allows adding the full specification of other objects using the extraDeploy parameter. The following example would activate a plugin at deployment time.

## <a id="extra-objects-to-deploy-value"></a> Extra objects to deploy (value evaluated as a template)
##
extraDeploy:
  - |
    apiVersion: configuration.konghq.com/v1
    kind: KongPlugin
    metadata:
      name: {{ include "common.names.fullname" . }}-plugin-correlation
      namespace: {{ .Release.Namespace }}
      labels: {{- include "common.labels.standard" ( dict "customLabels" .Values.commonLabels "context" $ ) | nindent 6 }}
    config:
      header_name: my-request-id
    plugin: correlation-id

⁠ Setting Pod's affinity

This chart allows you to set your custom affinity using the affinity parameter. Find more information about Pod's 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.

⁠ 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.

⁠ Parameters

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

⁠ Global parameters

⁠ Common parameters

⁠ Kong common parameters

⁠ Kong deployment / daemonset 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-kong-index.html⁠