Custom Runner Images for BYOC Pro

• Include custom dependencies and libraries
• Use specific versions of runtime environments
• Customize the execution environment for your workloads
• Package application-specific configurations

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Prerequisites

• BYOC Pro cluster with trusted mode enabled
• Docker installed and configured
• Access to a Docker registry (Docker Hub, private registry, etc.)
• Basic understanding of Dockerfile syntax and container concepts

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Base Images

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Java Functions

• Registry: streamnative/pulsar-functions-pulsarctl-java-runner

FROM streamnative/pulsar-functions-pulsarctl-java-runner:4.0.5.2

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Python Functions

• Registry: streamnative/pulsar-functions-pulsarctl-python-runner

FROM streamnative/pulsar-functions-pulsarctl-python-runner:4.0.5.2

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Building Custom Images

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1. Create Dockerfile

FROM streamnative/pulsar-functions-pulsarctl-java-runner:4.0.5.2

# Install additional system packages if needed
USER root
RUN apt-get update && apt-get install -y your-package
USER $UID
# Copy your function JAR and dependencies
COPY --chown=$UID:$GID example-function.jar /pulsar/
COPY --chown=$UID:$GID dependencies/ /pulsar/lib/

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2. Build and Push Image

# Build the Docker image
docker build -t your-registry/custom-function:v1.0 .

# Push to your registry
docker push your-registry/custom-function:v1.0

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3. Deploy Function with Custom Image

snctl pulsar admin functions create \
  --tenant your-tenant \
  --namespace your-namespace \
  --name custom-function \
  --jar example-function.jar \
  --classname com.example.MyFunction \
  --inputs input-topic \
  --output output-topic \
  --custom-runtime-options '{"runnerImage": "your-registry/custom-function:v1.0"}'

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Examples

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Java Function with Custom Dependencies

FROM streamnative/pulsar-functions-pulsarctl-java-runner:4.0.5.2

# Copy function JAR and custom dependencies
COPY --chown=$UID:$GID target/my-function.jar /pulsar/
COPY --chown=$UID:$GID target/lib/*.jar /pulsar/lib/

# Copy additional configuration files
COPY --chown=$UID:$GID config/logging.properties /pulsar/conf/

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Configuration with Other Trusted Mode Options

{
  "runnerImage": "your-registry/custom-function:v1.0",
  "javaOPTs": ["-Dmy.custom.config=value"]
}

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Best Practices

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Security

• Use minimal base images to reduce attack surface
• Scan images for vulnerabilities before deployment
• Use private registries for proprietary code
• Follow principle of least privilege for container permissions

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Performance

• Optimize image layers for efficient caching
• Remove unnecessary files and packages
• Use multi-stage builds for smaller final images
• Consider image pull time in high-throughput scenarios

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Maintenance

• Tag images with semantic versions
• Maintain compatibility with StreamNative base image updates
• Document custom dependencies and configurations
• Test images thoroughly before production deployment

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Troubleshooting

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Common Issues

• Verify registry credentials and access permissions
• Check network connectivity from cluster to registry
• Ensure image tag exists and is properly formatted

• Verify --chown=$UID:$GID is used for all COPY operations
• Check that files have correct permissions within the image
• Ensure service account has proper Kubernetes permissions

• Validate base image compatibility with cluster version
• Check that required dependencies are properly installed
• Verify classpath and module path configurations