Running DICOM Capacitor in Docker

DICOM Capacitor is available as a Docker image at fluxinc/dicom-capacitor. The image supports both amd64 and arm64 architectures.

Quick Start

mkdir -p data cache
docker run -d \
  --name capacitor \
  -p 1040:1040 \
  -p 1080:1080 \
  -v ./data:/data \
  -v ./cache:/cache \
  fluxinc/dicom-capacitor:latest

The web dashboard is available at http://localhost:1080. Check the logs for the activation URL on first run:

docker logs capacitor

Docker Compose

# compose.yaml
services:
  capacitor:
    image: fluxinc/dicom-capacitor:latest
    ports:
      - "1040:1040"             # Store SCP (main DICOM storage)
      - "1080:1080"             # Web UI and REST API
      - "1041:1041"             # Worklist/Find SCP (optional)
      - "2763:2763"             # Query/Retrieve SCP (optional)
      - "1042:1042"             # Storage Commit SCP (optional)
    volumes:
      - ./data:/data
      - ./cache:/cache
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "echoscu", "-aec", "FLUX_CAPACITOR", "localhost", "1040"]
      interval: 30s
      timeout: 10s
      retries: 3

Volumes

The container uses two mount points:

Volume	Purpose
/data	Configuration files (config.yml, nodes.yml, lua.yml, scripts), licensing, logs
/cache	DICOM file processing cache (incoming, prepared, failed, etc.)

Create the directories before starting and ensure the container user has read/write access:

mkdir -p ./data ./cache
chown -R 1000:1000 ./data ./cache   # Match the container user

You can optionally set the user: directive in your compose file to run as a specific UID/GID:

user: "1000:1000"

Port Mappings

Expose only the services you need:

Port	Service	Required?
1040	Store SCP (receive DICOM images)	Yes
1080	Web UI and REST API	Recommended
1041	Worklist/Find SCP	Optional
2763	Query/Retrieve SCP (C-FIND/C-MOVE)	Optional
1042	Storage Commitment SCP	Optional

Disable any SCP by setting its port to 0 in config.yml or via environment variable (e.g., CAPACITOR_FIND_SCP_PORT=0).

Configuration via Environment Variables

Most config.yml settings can be overridden via environment variables using the CAPACITOR_ prefix. Property names are converted from camelCase to UPPER_SNAKE_CASE:

config.yml	Environment Variable
myAeTitle	CAPACITOR_MY_AE_TITLE
scpPort	CAPACITOR_SCP_PORT
filters	CAPACITOR_FILTERS
processDelay	CAPACITOR_PROCESS_DELAY
processDelayWindowMultiplier	CAPACITOR_PROCESS_DELAY_WINDOW_MULTIPLIER
suppressWebLog	CAPACITOR_SUPPRESS_WEB_LOG

environment:
  CAPACITOR_MY_AE_TITLE: "MY_ROUTER"
  CAPACITOR_SCP_PORT: "11112"
  CAPACITOR_FILTERS: "lua"
  CAPACITOR_SUPPRESS_WEB_LOG: "true"   # Suppress web/API log file output

Environment variables override config.yml settings. Command-line overrides (--config.*) take highest priority.

Health Checks

The recommended health check uses echoscu (included in the container) to send a DICOM C-ECHO:

healthcheck:
  test: ["CMD", "echoscu", "-aec", "FLUX_CAPACITOR", "localhost", "1040"]
  interval: 30s
  timeout: 10s
  retries: 3

Replace FLUX_CAPACITOR with your configured myAeTitle. You can check the health status with:

docker inspect --format='{{.State.Health.Status}}' capacitor

Viewing Logs

# Follow logs in real-time
docker compose logs -f capacitor

# View last 100 lines
docker compose logs --tail=100 capacitor

The service log is also written to the /data/log/ volume, so you can access capacitor_service.log directly from the host:

tail -f ./data/log/capacitor_service.log

Web/API request logs are written to a separate file (capacitor_service_web.log) to keep the main log focused on DICOM operations. To suppress web logs entirely (recommended in Docker), set CAPACITOR_SUPPRESS_WEB_LOG=true.

Upgrading

docker compose pull
docker compose up -d

Configuration files in ./data/ are preserved across upgrades. Only the container image is replaced.

Troubleshooting

Symptom	Check
No DICOM response on expected port	Verify port mapping matches scpPort (default 1040 inside container)
Web UI not accessible	Ensure port 1080 is mapped: -p 1080:1080
Permission denied on volumes	Ensure host directory ownership matches container user (chown 1000:1000)
Activation required	Check logs for activation URL: docker compose logs capacitor
Container keeps restarting	Check logs for startup errors: docker compose logs --tail=50 capacitor
Images stuck in cache	Verify destination is reachable from inside the container: docker exec capacitor echoscu -aec DEST_AE host port