Update Dockerfile

Dockerfile

@@ -1,17 +1,22 @@
-# Use an appropriate base image with Python pre-installed
-FROM alpine:3.18
+# Step 1: Use an official, slim Python image as a base
+# 'slim' is a good balance between size and functionality.
+FROM python:3.11-slim
 
 # Set the working directory inside the container
 WORKDIR /app
 
-# Copy the entire current directory into the container at /app
-COPY . /app
+# Step 2: Copy only the requirements file
+# This makes optimal use of Docker's layer caching.
+COPY requirements.txt .
 
-# Install any Python dependencies
+# Step 3: Install the dependencies
+# The --no-cache-dir option keeps the image smaller.
+RUN pip install --no-cache-dir -r requirements.txt
 
-RUN apk add python3
-RUN apk add py3-pip
-RUN pip install -r requirements.txt
+# Step 4: Now, copy the rest of the application code
+# Because the code changes more often than the dependencies, this step is placed later.
+COPY . .
 
-# Run Python script
-CMD ["python", "main.py"]
+# Step 5: Execute the correct Python script
+# Note the correct filename.
+CMD ["python3", "masto-rss.py"]