Update base image to Ubuntu 22.04

Dockerfile

@@ -1,30 +1,51 @@
-# Pull base image.
-FROM jlesage/baseimage-gui:ubuntu-20.04-v4
+# Pull base image
+FROM jlesage/baseimage-gui:ubuntu-22.04-v4
 
-# Install Dependencies
-RUN apt-get update && \
-    apt-get -y upgrade && \
-    apt-get -y install --no-install-recommends apt-transport-https ca-certificates wget libglu1 libgtk2.0-0
+# Set environment variables
+ENV DEBIAN_FRONTEND=noninteractive \
+    MKVTOOLNIX_VERSION=73.0.0-0~ubuntu2204bunkus01 \
+    INVISKA_VERSION=11.0
 
-# Install MKVToolnix 73 - https://mkvtoolnix.download/downloads.html#ubuntu
-# MKVToolnix 73 is the last version that is compatible with Inviska. MKVToolnix 74 or newer is NOT compatible!
-RUN wget -O /usr/share/keyrings/gpg-pub-moritzbunkus.gpg https://mkvtoolnix.download/gpg-pub-moritzbunkus.gpg && \
-    sh -c 'echo "deb [arch=amd64 signed-by=/usr/share/keyrings/gpg-pub-moritzbunkus.gpg] https://mkvtoolnix.download/ubuntu/ $(. /etc/os-release && echo $VERSION_CODENAME) main" >> /etc/apt/sources.list.d/mkvtoolnix.list' && \
-    apt-get update && \
-    apt-get -y install --no-install-recommends mkvtoolnix=73.0.0-0~ubuntu2004bunkus01 && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/*
+# MKVToolnix 73 is the last version compatible with Inviska. MKVToolnix 74 or newer will not work!
+# hadolint ignore=DL3008
+RUN set -eux \
+    # First install wget and other basic dependencies
+    && apt-get update \
+    && apt-get -y upgrade \
+    && apt-get install -y --no-install-recommends \
+        apt-transport-https \
+        ca-certificates \
+        wget \
+    # Now add MKVToolnix repository
+    && wget -qO /usr/share/keyrings/gpg-pub-moritzbunkus.gpg https://mkvtoolnix.download/gpg-pub-moritzbunkus.gpg \
+    && echo "deb [arch=amd64 signed-by=/usr/share/keyrings/gpg-pub-moritzbunkus.gpg] https://mkvtoolnix.download/ubuntu/ jammy main" > /etc/apt/sources.list.d/mkvtoolnix.list \
+    && echo "deb-src [arch=amd64 signed-by=/usr/share/keyrings/gpg-pub-moritzbunkus.gpg] https://mkvtoolnix.download/ubuntu/ jammy main" >> /etc/apt/sources.list.d/mkvtoolnix.list \
+    # Update again with new repository and install remaining packages
+    && apt-get update \
+    && apt-get install -y --no-install-recommends \
+        libglu1 \
+        libgtk2.0-0 \
+        mkvtoolnix=${MKVTOOLNIX_VERSION} \
+    # Download Inviska
+    && wget -q https://raw.githubusercontent.com/Freekers/docker-inviska/main/Inviska_MKV_Extract-${INVISKA_VERSION}-x86_64.AppImage -P /opt/ \
+    && chmod +x /opt/Inviska_MKV_Extract-${INVISKA_VERSION}-x86_64.AppImage \
+    # Cleanup
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/* \
+    && rm -rf /tmp/*
 
-# Download Inviska
-RUN wget https://raw.githubusercontent.com/Freekers/docker-inviska/main/Inviska_MKV_Extract-11.0-x86_64.AppImage -P /opt/ && \
-    chmod +x /opt/Inviska_MKV_Extract-11.0-x86_64.AppImage
-
-# Copy the start script.
+# Copy and prepare the start script
 COPY startapp.sh /startapp.sh
 RUN chmod +x /startapp.sh
 
-# Define mountable directories.
+# Define mountable directories
 VOLUME ["/media"]
 
-# Set the name of the application.
+# Set the application name
 RUN set-cont-env APP_NAME "Inviska"
+
+# Add labels for better maintainability
+LABEL maintainer="Freekers" \
+      version="1.0" \
+      description="Inviska MKV Extract Docker Image" \
+      org.opencontainers.image.source="https://github.com/Freekers/docker-inviska"