Use slim image

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Now uses the `slim` variant of the official Node image to reduce image size by ~300 MB
 
 ## [2.1.5] - 2022-08-26
 ### Fixed

Dockerfile

@@ -1,8 +1,8 @@
-FROM node:18.7.0 AS base
+FROM node:18.7.0-slim AS base
 
 # Install ffmpeg
 RUN apt-get update && \
-    apt-get install -y ffmpeg tini && \
+    apt-get install -y ffmpeg tini libssl-dev ca-certificates && \
     rm -rf /var/lib/apt/lists/*
 
 # Install dependencies