Creating custom Rock server images

Dick Postma and Xavier Escribà Montagut

Overview

Goal: Build custom Rock server Docker images with specific DataSHIELD packages

Why custom images?

• 🔒 Version control - Pin specific package versions for reproducibility
• 🎯 Consistency - Ensure all environments use identical packages
• 📦 Distribution - Share images across teams and deployments

Base Images Available

DataSHIELD provides base images:

• datashield/rock-base:6.3-R4.3 - Minimal Rock server with R 4.3
• obiba/rock:latest - Standard Rock just with resourcer

Naming convention: {dsBase-version}-R{R-version}

Example: 6.3-R4.3 = dsBase v6.3 + R v4.3

Dockerfile Structure

Basic template for custom Rock images:

FROM datashield/rock-base:6.3-R4.3

# Define package versions for reproducibility
ENV DSURVIVAL_VERSION v2.3.0-dev

# Rock library path
ENV ROCK_LIB /var/lib/rock/R/library

# Install DataSHIELD packages
RUN Rscript -e "remotes::install_github('datashield/dsSurvival', \
    ref = '$DSURVIVAL_VERSION', lib = '$ROCK_LIB')"

# Fix ownership (Rock runs as non-root user)
RUN chown -R rock $ROCK_LIB

Building the Image

# Build with descriptive tag
docker build -f Dockerfile.survival -t rock-survival:v2.3.0 .

# Build with multiple tags
docker build -f Dockerfile.survival \
  -t rock-survival:v2.3.0 \
  -t rock-survival:latest \
  .

Best practice: Always tag with version numbers!

Testing Your Custom Image

# Run the custom image
docker run -d --name test-survival-rock \
  -p 8085:8085 \
  rock-survival:v2.3.0

# Verify packages are installed
docker exec test-survival-rock \
  Rscript -e "library(dsSurvival); packageVersion('dsSurvival')"

# Clean up
docker stop test-survival-rock
docker rm test-survival-rock

Tagging Strategy

Use semantic versioning:

# Development versions
docker build -t rock-survival:v2.3.0-dev .

# Release versions  
docker build -t rock-survival:v2.3.0 .
docker build -t rock-survival:latest .

# Environment-specific tags
docker build -t rock-survival:production .
docker build -t rock-survival:staging .

Distribution via Registry

Push to Docker Hub:

# Tag for your registry
docker tag rock-survival:v2.3.0 \
  your-dockerhub-username/rock-survival:v2.3.0

# Push to registry
docker push your-dockerhub-username/rock-survival:v2.3.0

Pull on other systems:

docker pull your-dockerhub-username/rock-survival:v2.3.0

Summary

✅ Achieved: Custom Rock server images with specific packages

🎯 Benefits: - Reproducible environments across deployments - Version-controlled package management - Team collaboration and sharing

🚀 Ready for: Production deployment with consistent environments!