Open WebUI integration

Open WebUI is an open-source, self-hosted web interface that provides a ChatGPT-like experience for local AI models. You can connect it to Docker Model Runner to get a polished chat interface for your models.

Prerequisites

• Docker Model Runner enabled with TCP access
• A model pulled (e.g., docker model pull ai/llama3.2)

Quick start with Docker Compose

The easiest way to run Open WebUI with Docker Model Runner is using Docker Compose.

Create a compose.yaml file:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "3000:8080"
    environment:
      - OLLAMA_BASE_URL=http://host.docker.internal:12434
      - WEBUI_AUTH=false
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - open-webui:/app/backend/data

volumes:
  open-webui:

Start the services:

$ docker compose up -d

Open your browser to http://localhost:3000.

Configuration options

Environment variables

Using OpenAI-compatible API

If you prefer to use the OpenAI-compatible API instead of the Ollama API:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "3000:8080"
    environment:
      - OPENAI_API_BASE_URL=http://host.docker.internal:12434/engines/v1
      - OPENAI_API_KEY=not-needed
      - WEBUI_AUTH=false
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - open-webui:/app/backend/data

volumes:
  open-webui:

Network configuration

Docker Desktop

On Docker Desktop, host.docker.internal automatically resolves to the host machine. The previous example works without modification.

Docker Engine (Linux)

On Docker Engine, you may need to configure the network differently:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    network_mode: host
    environment:
      - OLLAMA_BASE_URL=http://localhost:12434
      - WEBUI_AUTH=false
    volumes:
      - open-webui:/app/backend/data

volumes:
  open-webui:

Or use the host gateway:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "3000:8080"
    environment:
      - OLLAMA_BASE_URL=http://172.17.0.1:12434
      - WEBUI_AUTH=false
    volumes:
      - open-webui:/app/backend/data

volumes:
  open-webui:

Using Open WebUI

Select a model

1. Open http://localhost:3000
2. Select the model drop-down in the top-left
3. Select from your pulled models (they appear with ai/ prefix)

Pull models through the UI

Open WebUI can pull models directly:

1. Select the model drop-down
2. Enter a model name: ai/llama3.2
3. Select the download icon

Chat features

Open WebUI provides:

• Multi-turn conversations with context
• Message editing and regeneration
• Code syntax highlighting
• Markdown rendering
• Conversation history and search
• Export conversations

Complete example with multiple models

This example sets up Open WebUI with Docker Model Runner and pre-pulls several models:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "3000:8080"
    environment:
      - OLLAMA_BASE_URL=http://host.docker.internal:12434
      - WEBUI_AUTH=false
      - DEFAULT_MODELS=ai/llama3.2
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - open-webui:/app/backend/data
    depends_on:
      model-setup:
        condition: service_completed_successfully

  model-setup:
    image: docker:cli
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    command: >
      sh -c "
        docker model pull ai/llama3.2 &&
        docker model pull ai/qwen2.5-coder &&
        docker model pull ai/smollm2
      "

volumes:
  open-webui:

Enabling authentication

For multi-user setups or security, enable authentication:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "3000:8080"
    environment:
      - OLLAMA_BASE_URL=http://host.docker.internal:12434
      - WEBUI_AUTH=true
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - open-webui:/app/backend/data

volumes:
  open-webui:

On first visit, you'll create an admin account.

Troubleshooting

Models don't appear in the drop-down

1. Verify Docker Model Runner is accessible:

   $ curl http://localhost:12434/api/tags
   

2. Check that models are pulled:

   $ docker model list
   

3. Verify the OLLAMA_BASE_URL is correct and accessible from the container.

"Connection refused" errors

1. Ensure TCP access is enabled for Docker Model Runner.

2. On Docker Desktop, verify host.docker.internal resolves:

   $ docker run --rm alpine ping -c 1 host.docker.internal
   

3. On Docker Engine, try using network_mode: host or the explicit host IP.

Slow response times

1. First requests load the model into memory, which takes time.

2. Subsequent requests are much faster.

3. If consistently slow, consider:

   • Using a smaller model
   • Reducing context size
   • Checking GPU acceleration is working

CORS errors

If running Open WebUI on a different host:

1. In Docker Desktop, go to Settings > AI
2. Add the Open WebUI URL to CORS Allowed Origins

Customization

Custom system prompts

Open WebUI supports setting system prompts per model. Configure these in the UI under Settings > Models.

Model parameters

Adjust model parameters in the chat interface:

1. Select the settings icon next to the model name
2. Adjust temperature, top-p, max tokens, etc.

These settings are passed through to Docker Model Runner.

Running on a different port

To run Open WebUI on a different port:

services:
  open-webui:
    image: ghcr.io/open-webui/open-webui:main
    ports:
      - "8080:8080"  # Change first port number
    # ... rest of config

What's next

• API reference - Learn about the APIs Open WebUI uses
• Configuration options - Tune model behavior
• IDE integrations - Connect other tools to DMR