DOC add gpu compute worker setup guide

codabench_gpu_worker.md

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+# Attaching a GPU Compute Worker on AWS to a Codabench Competition
+
+This guide explains how to set up and attach a **GPU-enabled Codabench compute worker** running on an **AWS EC2 instance**.
+
+---
+
+## 1. Overview
+
+Codabench uses **compute workers** to execute competition submissions.  
+Each worker connects to a **broker URL** (defined in your Codabench admin panel) and runs submissions inside **competition Docker images**.
+
+For GPU-based evaluations, workers must:
+- Run on GPU-capable hardware (e.g. AWS `g4dn.xlarge`, `g5.xlarge`, or `p3.2xlarge`)
+- Have NVIDIA drivers and CUDA-compatible Docker support
+- Use the image `codalab/competitions-v2-compute-worker:gpu1.3` or a custom image based on it.
+
+---
+
+## 2. Launch an AWS EC2 GPU Instance
+
+1. Open **AWS EC2 Console** → “Launch instance”
+2. Choose an **Ubuntu 24.04 LTS** (64-bit x86) AMI
+3. Select a **GPU instance type**, e.g.:
+   - `g4dn.xlarge` (Tesla T4)
+   - `g5.xlarge` (A10G)
+4. Configure:
+   - Storage: at least **50 GB**
+   - Key pair: securely connect to instance
+   - Security group: allow inbound **SSH (port 22)**
+5. Launch the instance and connect via SSH (you can find 'ec2-public-ip' in instance summary->Public DNS):
+   ```bash
+   ssh -i your-key.pem ubuntu@<ec2-public-ip>
+   ```
+
+
+## 3. Install NVIDIA GPU Drivers
+
+```bash
+sudo apt update && sudo apt upgrade -y
+sudo apt install -y nvidia-driver-580
+sudo reboot
+```
+After reboot:
+```bash
+nvidia-smi
+```
+You should see the GPU (e.g. Tesla T4)
+
+
+## 4. Install Docker
+
+Set up Docker's apt repository:
+```bash
+# Add Docker's official GPG key:
+sudo apt update
+sudo apt install ca-certificates curl
+sudo install -m 0755 -d /etc/apt/keyrings
+sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
+sudo chmod a+r /etc/apt/keyrings/docker.asc
+
+# Add the repository to Apt sources:
+sudo tee /etc/apt/sources.list.d/docker.sources <<EOF
+Types: deb
+URIs: https://download.docker.com/linux/ubuntu
+Suites: $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}")
+Components: stable
+Signed-By: /etc/apt/keyrings/docker.asc
+EOF
+
+sudo apt update
+```
+
+Install Docker packages:
+```bash
+sudo apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
+```
+
+Enable Docker at startup:
+```bash
+sudo systemctl enable docker
+```
+Allow the ubuntu user to use Docker without sudo:
+```bash
+sudo usermod -aG docker ubuntu
+```
+Log out and back in for the group change to take effect.
+
+
+## 5. Install NVIDIA Container Toolkit
+
+Prerequisites:
+```bash
+sudo apt-get update && sudo apt-get install -y --no-install-recommends curl gnupg2
+```
+Configure the production repository:
+```bash
+curl -fsSL https://nvidia.github.io/libnvidia-container/gpgkey | sudo gpg --dearmor -o /usr/share/keyrings/nvidia-container-toolkit-keyring.gpg \
+  && curl -s -L https://nvidia.github.io/libnvidia-container/stable/deb/nvidia-container-toolkit.list | \
+    sed 's#deb https://#deb [signed-by=/usr/share/keyrings/nvidia-container-toolkit-keyring.gpg] https://#g' | \
+    sudo tee /etc/apt/sources.list.d/nvidia-container-toolkit.list
+```
+```bash
+sudo apt-get update
+```
+Install the NVIDIA Container Toolkit packages:
+```bash
+export NVIDIA_CONTAINER_TOOLKIT_VERSION=1.18.0-1
+  sudo apt-get install -y \
+      nvidia-container-toolkit=${NVIDIA_CONTAINER_TOOLKIT_VERSION} \
+      nvidia-container-toolkit-base=${NVIDIA_CONTAINER_TOOLKIT_VERSION} \
+      libnvidia-container-tools=${NVIDIA_CONTAINER_TOOLKIT_VERSION} \
+      libnvidia-container1=${NVIDIA_CONTAINER_TOOLKIT_VERSION}
+```
+
+Configuring Docker to use NVIDIA runtime:
+```bash
+sudo nvidia-ctk runtime configure --runtime=docker
+```
+
+Restart Docker:
+```bash
+sudo systemctl restart docker
+```
+This will generate or update:
+```bash
+/etc/docker/daemon.json
+```
+The JSON file now contains:
+```bash
+{
+    "runtimes": {
+        "nvidia": {
+            "args": [],
+            "path": "nvidia-container-runtime"
+        }
+    }
+```
+
+We can test the runtime manually with:
+```bash
+sudo docker run --rm --runtime=nvidia --gpus all nvidia/cuda:12.2.0-base-ubuntu22.04 nvidia-smi
+```
+
+
+## 6. Configure the Codabench Worker
+
+Create a working directory on the EC2 host:
+```bash
+mkdir -p /home/ubuntu/codabench
+```
+
+Create an ```.env``` file in ```/home/ubuntu/codabench```:
+```bash
+BROKER_URL=<your-codabench-broker-url>
+BROKER_USE_SSL=True
+HOST_DIRECTORY=/home/ubuntu/codabench
+```
+The broker URL corresponding to the selected queue can be found on Codabench website under Admin panel->My Resources->Queues and then Actions->Copy Broker URL. The queue is to be specified in the Edit section of the competition on Codabench. 
+
+
+## 7. Create ```docker-compose.yml``` for the GPU Worker
+
+Inside ```/home/ubuntu/codabench```, create a file named ```docker-compose.yml``` and copy:
+```yaml
+# Codabench GPU worker (NVIDIA)
+services:
+    worker:
+        image: codalab/competitions-v2-compute-worker:gpu1.3
+        container_name: compute_worker
+        volumes:
+            - /home/ubuntu/codabench:/codabench
+            - /var/run/docker.sock:/var/run/docker.sock
+        env_file:
+            - .env
+        restart: unless-stopped
+        #hostname: ${HOSTNAME}
+        logging:
+            options:
+                max-size: 50m
+                max-file: 3
+        deploy:
+            resources:
+                reservations:
+                    devices:
+                        - driver: nvidia
+                          count: all
+                          capabilities:
+                              - gpu
+```
+
+
+## 8. Start the GPU Worker
+
+From ```/home/ubuntu/codabench```:
+```bash
+docker compose up -d
+```
+Check running containers:
+```bash
+docker ps
+```
+Check logs of the ```compute_worker``` container:
+```bash
+docker logs -f compute_worker
+```
+The compute worker container should be ready to receive submissions from Codabench.
+
+## 9. Stop compute worker instance
+
+First stop the container:
+```bash
+docker compose down
+```
+Then stop the EC2 instance from AWS console.
+