fix dockerfile

Author: Lgdev07

Dockerfile

@@ -1,5 +1,5 @@
-# Using hexpm/elixir:1.11.4-erlang-23.2.7.2-alpine-3.13.3 as the base image
-FROM hexpm/elixir:1.11.4-erlang-23.2.7.2-alpine-3.13.3 AS base
+# Using elixir:1.18.3-otp-27-slim as the base image
+FROM elixir:1.18.3-otp-27-slim AS base
 
 # Set the working directory in the container
 WORKDIR /code_comparison
@@ -8,7 +8,10 @@ WORKDIR /code_comparison
 # npm is needed for asset building.
 # inotify-tools is often for development (auto-reload), might not be strictly needed for a prod build,
 # but keeping it as per original Dockerfile's intent for now.
-RUN apk add --no-cache npm inotify-tools
+RUN apt-get update && \
+    apt-get install -y npm inotify-tools && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
 
 # Set environment variables for production
 ENV MIX_ENV=prod
@@ -18,16 +21,15 @@ ENV PORT=4000
 # This includes the 'topics/' directory, mix files, config, lib, assets, etc.
 COPY . .
 
-# Provide a dummy SECRET_KEY_BASE for compilation, must be at least 64 bytes long for prod.
-# This will be overridden by the runtime environment variable on Render.
-ENV SECRET_KEY_BASE="dummy_build_time_secret_key_base_must_be_at_least_64_bytes_long_for_prod_build_0123456789"
+# Generate a temporary SECRET_KEY_BASE for build time
+RUN mix phx.gen.secret > /tmp/secret_key_base
 
 # Install Elixir dependencies
 # --force is used to ensure local hex and rebar are up-to-date
 RUN mix local.hex --force && \
     mix local.rebar --force && \
     mix deps.get --only prod && \
-    mix deps.compile
+    SECRET_KEY_BASE=$(cat /tmp/secret_key_base) mix deps.compile
 
 # Build frontend assets
 # This assumes your assets/package.json has a "deploy" script.
@@ -42,8 +44,11 @@ RUN npm install --prefix ./assets && \
 
 # Compile the Phoenix application and digest assets
 # phx.digest prepares static assets (CSS, JS, images) for production.
-RUN mix phx.digest && \
-    mix compile
+RUN SECRET_KEY_BASE=$(cat /tmp/secret_key_base) mix phx.digest && \
+    SECRET_KEY_BASE=$(cat /tmp/secret_key_base) mix compile
+
+# Clean up the temporary secret key
+RUN rm /tmp/secret_key_base
 
 # Expose the port the application will run on
 EXPOSE ${PORT}