latest changes

Dockerfile

@@ -0,0 +1,98 @@
+# Use an official Python runtime as a parent image, choosing one that includes Node.js
+# Check Docker Hub for suitable tags (e.g., python:3.9-slim-bullseye might need Node installed)
+# Or use a Node image and install Python. Let's try a Node base and add Python.
+FROM node:18-slim
+
+# Install Python, pip, and venv
+# 'apt-get update && apt-get install -y --no-install-recommends' is standard practice
+# 'rm -rf /var/lib/apt/lists/*' cleans up afterward to keep image size down
+# Install Python, pip, venv, and Puppeteer dependencies
+# See: https://pptr.dev/troubleshooting#running-puppeteer-on-debian
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    python3 \
+    python3-pip \
+    python3-venv \
+    # Puppeteer dependencies:
+    ca-certificates \
+    fonts-liberation \
+    libasound2 \
+    libatk-bridge2.0-0 \
+    libatk1.0-0 \
+    libcairo2 \
+    libcups2 \
+    libdbus-1-3 \
+    libexpat1 \
+    libfontconfig1 \
+    libgbm1 \
+    libgcc1 \
+    libglib2.0-0 \
+    libgtk-3-0 \
+    libnspr4 \
+    libnss3 \
+    libpango-1.0-0 \
+    libpangocairo-1.0-0 \
+    libstdc++6 \
+    libx11-6 \
+    libx11-xcb1 \
+    libxcb1 \
+    libxcomposite1 \
+    libxcursor1 \
+    libxdamage1 \
+    libxext6 \
+    libxfixes3 \
+    libxi6 \
+    libxrandr2 \
+    libxrender1 \
+    libxss1 \
+    libxtst6 \
+    lsb-release \
+    wget \
+    xdg-utils \
+    && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Install mermaid-cli globally
+# Use --unsafe-perm if needed for permissions during global install
+RUN npm install -g @mermaid-js/mermaid-cli --unsafe-perm=true
+
+# Copy the requirements file first to leverage Docker cache
+COPY requirements.txt ./
+
+# Create a virtual environment and install Python dependencies
+# This isolates Python packages within the container, similar to local setup
+RUN python3 -m venv /app/venv
+# Activate venv for the RUN command and install packages
+RUN . /app/venv/bin/activate && pip install --no-cache-dir -r requirements.txt
+
+# Copy the rest of the application code into the container
+COPY . .
+
+# Make port 5001 available to the world outside this container
+# This should match the port Flask runs on in app.py (or Gunicorn config)
+EXPOSE 5001
+
+# Define environment variables
+# IMPORTANT: Set a strong FLASK_SECRET_KEY when running the container!
+# Using a placeholder here for demonstration.
+ENV FLASK_APP=app.py
+ENV FLASK_RUN_HOST=0.0.0.0
+ENV FLASK_RUN_PORT=5001
+ENV FLASK_SECRET_KEY="replace_this_in_docker_run_with_a_real_secret"
+# Add venv's bin to the PATH for subsequent commands (like CMD)
+ENV PATH="/app/venv/bin:$PATH"
+
+# Override base image entrypoint so CMD executes directly
+ENTRYPOINT []
+
+# Run the application using Gunicorn when the container launches
+# Use the full path to gunicorn within the virtual environment
+# Bind to 0.0.0.0 to accept connections from outside the container
+# Use the port defined by FLASK_RUN_PORT
+# The number of workers (e.g., --workers 3) can be adjusted based on server resources
+# Use JSON form with the absolute path to gunicorn in the venv to avoid PATH issues
+CMD ["/app/venv/bin/gunicorn", "--workers", "3", "--bind", "0.0.0.0:5001", "app:app"]

README.md

@@ -35,46 +35,55 @@ This Flask application provides a web interface for rendering diagrams from [Mer
 ├── requirements.txt        # Python dependencies (Flask)
 ├── templates/
 │   └── index.html          # HTML template for the web interface
-├── venv/                   # Python virtual environment (created locally/on server)
+├── Dockerfile              # Instructions to build the Docker image
 └── README.md               # This file
 ```
 
 ## Prerequisites
 
-### Local Machine (for testing)
+*   [Docker](https://docs.docker.com/get-docker/) installed on your local machine or deployment server.
 
-*   Python 3 & pip
-*   Node.js & npm
-*   `@mermaid-js/mermaid-cli` installed globally (`npm install -g @mermaid-js/mermaid-cli`)
+## Deployment with Docker
 
-### Azure Ubuntu VM (for deployment)
+This is the recommended way to run the application, as it bundles all dependencies.
 
-*   An Azure Virtual Machine running Ubuntu (e.g., Ubuntu 20.04 LTS or later).
-*   SSH access to the VM.
-*   Ability to configure Network Security Groups (NSGs) in Azure portal.
-*   `sudo` privileges on the VM.
-
-## Local Testing
-
-1.  **Clone/Download:** Get the application files (`app.py`, `mermaid_renderer.py`, `requirements.txt`, `templates/`).
-2.  **Install Prerequisites:** Ensure Python 3, pip, Node.js, npm, and `@mermaid-js/mermaid-cli` are installed locally.
-3.  **Create Virtual Environment:**
+1.  **Clone/Download:** Get the application files (`app.py`, `mermaid_renderer.py`, `requirements.txt`, `templates/`, `Dockerfile`).
+2.  **Generate Secret Key:** Create a strong secret key for Flask sessions. You can generate one using:
     ```bash
-    cd /path/to/project/directory
-    python3 -m venv venv
-    source venv/bin/activate
+    python -c 'import secrets; print(secrets.token_hex(16))'
     ```
-4.  **Install Dependencies:**
+    Keep this key safe and use it in the next step.
+3.  **Build the Docker Image:** Navigate to the project directory in your terminal and run:
     ```bash
-    pip install -r requirements.txt
+    # Replace 'mermaid-renderer-app' with your desired image name/tag
+    docker build -t mermaid-renderer-app .
     ```
-5.  **Run Development Server:**
+4.  **Run the Docker Container:**
     ```bash
-    python app.py
+    # Replace 'YOUR_GENERATED_SECRET_KEY' with the key from step 2.
+    # -d: Run in detached mode (background)
+    # -p 80:5001: Map port 80 on the host to port 5001 in the container
+    # --name mermaid-app: Assign a name to the container for easier management
+    # -e FLASK_SECRET_KEY=...: Set the environment variable inside the container
+    # mermaid-renderer-app: The name of the image to run
+    docker run -d -p 80:5001 --name mermaid-app \
+      -e FLASK_SECRET_KEY='YOUR_GENERATED_SECRET_KEY' \
+      mermaid-renderer-app
     ```
-6.  **Access:** Open your browser to `http://127.0.0.1:5001` (or the port specified in `app.py`).
+    *Note:* If port 80 is already in use on your host, choose a different host port (e.g., `-p 8080:5001`).
+
+5.  **Access the Application:** Open your web browser and navigate to `http://localhost` (or `http://your_server_ip` if deploying remotely). If you used a different host port, include it (e.g., `http://localhost:8080`).
+
+### Managing the Container
+
+*   **View logs:** `docker logs mermaid-app`
+*   **Stop:** `docker stop mermaid-app`
+*   **Start:** `docker start mermaid-app`
+*   **Remove (after stopping):** `docker rm mermaid-app`
+
+---
 
-## Deployment to Azure Ubuntu VM
+# Deployment to Azure Ubuntu VM
 
 These steps guide you through deploying the application using Gunicorn and Nginx.
 

makefile

@@ -0,0 +1,2 @@
+all:
+	python3 app.py