# 🐳 Consolidation: Defining Stable, Self-Contained Methods

The CCP platform supports two main approaches for method execution:

1. **Runtime-based methods** (simplified, flexible, ideal for prototyping)
2. **Consolidated methods** (fully packaged, stable, ideal for production)

This guide explains how to create a **consolidated method** — where all dependencies and code are bundled into a custom Docker image.

---

## 💡 Why Consolidate?

- Avoid dependency installation at runtime
- Ensure reproducibility, even in offline or secure environments
- Package complex environments (e.g., Java, R, C++ with specific libs)
- Protect source code if needed

---

## 🧱 What You Need

To consolidate a method, you must:

- Build a custom Docker image with:
  - Your code already cloned
  - All dependencies pre-installed
  - Entrypoint ready to run your method
- Push the image to a Docker registry (public or private)
- Reference the image in your `method.json`

---

## 🐳 Docker Image Structure

Start from a base image (e.g., `python:3.9`, `debian`, etc.) and:

1. Copy your scripts inside
2. Install any required libraries
3. Define a suitable entrypoint or script

### Example `Dockerfile` (Python)

```Dockerfile
FROM python:3.9-slim

WORKDIR /app
COPY . /app

RUN pip install -r requirements.txt

ENTRYPOINT ["python", "main.py"]
```

Then build and push:

```bash
docker build -t registry.org/myproject:1.0 .
docker push registry.org/myproject:1.0
```

---

## 📄 Update `method.json`

Reference the consolidated image:

```json
"ccpimage": {
  "default": "registry.org/myproject:1.0"
}
```

You don't need a deploy script — all preparation is baked into the image.

If your entrypoint uses arguments (e.g., `--input /ccp_data/input.txt`), CCP will still inject parameters in the execute script.

---

## 📁 File I/O Rules Still Apply

- CCP mounts the `/ccp_data/` folder inside your container
- You must **read all inputs** from this directory
- You must **write all outputs** to this directory

---

## 🧪 Testing Your Image

Before publishing, always test locally:

```bash
docker run -v $(pwd)/testdata:/ccp_data registry.org/myproject:1.0     --input /ccp_data/sample.csv --output /ccp_data/output.txt
```

---

## 🔐 Private Registries

If you want to use a private Docker image:

- You must configure CCP to authenticate with the registry
- This currently requires administrator-level integration

---

## ✅ Summary

| Feature                 | Runtime-based       | Consolidated         |
|-------------------------|---------------------|----------------------|
| Docker image            | CCP-provided        | Custom user image    |
| Dependency install      | At runtime          | Pre-installed        |
| Source code             | Cloned on the fly   | Included in image    |
| Internet required       | Yes                 | No                   |
| Performance             | Slower              | Faster, stable       |
| Use case                | Testing, prototyping| Production, secure   |

---

## 📌 Best Practices

- Use tags (e.g., `:1.0`) for immutable images
- Keep your Docker images small and clean
- Test your method on CCP after publishing the image

---

## 🔗 Related Pages

- 🔧 [Method development workflow](./01_method_development_flow.md)

- 🔣 [Structure of method.json](./07_method_json.md)

- 🐧 [Docker runtime input](./02_defining_ccpimage.md)