Run custom connectors in Helm charts

You can deploy a custom connector in your Helm Kubernetes cluster along with the connectors bundle.

The default runtime loads connectors from the classpath using the Java Service Provider Interface (SPI). For the custom connectors, there is a dedicated folder in the Connectors Docker image /opt/custom. Any JAR placed in this folder is included in the runtime classpath.

This page explains how to place your custom connector JAR in /opt/custom.

Prerequisites

• A custom connector built as a fat JAR (JAR with dependencies).
  For details on creating and building custom connectors, see Connector SDK.

  Example JAR name used in this guide:
  custom-connector-0.0.1-with-dependencies.jar

• A hosting location accessible by Helm during installation.
  Example path used in this guide:
  https://my.host:80/dist/custom-connector-0.0.1-with-dependencies.jar

Configure the Helm chart

Update the values of the Camunda Helm charts to download the JAR into /opt/custom before the connectors runtime starts:

connectors:
  initContainers:
    - name: init-script-downloader
      image: appropriate/curl
      args:
        - "-o"
        - "/opt/custom/custom-connector-0.0.1-with-dependencies.jar"
        - "https://my.host:80/dist/custom-connector-0.0.1-with-dependencies.jar"
      volumeMounts:
        - name: init-script
          mountPath: /opt/custom

  extraVolumes:
    - name: init-script
      emptyDir: {}

  extraVolumeMounts:
    - mountPath: /opt/custom/custom-connector-0.0.1-with-dependencies.jar
      name: init-script
      subPath: custom-connector-0.0.1-with-dependencies.jar

After updating the values, run Helm install as usual.

note

The appropriate/curl image is not the only image option for the initContainers. You can use other curl-based images, such as curlimages/curl. Adjust the args to match the image you choose.

Troubleshooting

If your custom connector does not start:

• Verify that your connector JAR is present in the /opt/custom folder in the pod.
• Confirm that the original connector JAR matches the one in /opt/custom. A file size check is often sufficient, but you can also compare checksums if needed.