5.4 prep: add experimental ushell support under Linux

src/ue4docker/dockerfiles/ue4-build-prerequisites/linux/Dockerfile

@@ -28,6 +28,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 		curl \
 		git \
 		git-lfs \
+		gpg-agent \
 		python3 \
 		python3-dev \
 		python3-pip \
@@ -93,5 +94,18 @@ RUN useradd --create-home --home /home/ue4 --shell /bin/bash --uid 1000 ue4 && \
 	usermod -a -G audio,video,sudo ue4
 USER ue4
 
+{% if enable_ushell %}
+# Install Python 3.12, which is required by ushell
+USER root
+RUN add-apt-repository -y ppa:deadsnakes/ppa && \
+	apt-get update && \
+	apt-get install -y --no-install-recommends python3.12 python3.12-venv && \
+	rm -rf /var/lib/apt/lists/*
+USER ue4
+
+# Install a copy of pip for Python 3.12
+RUN curl -fsSL 'https://bootstrap.pypa.io/get-pip.py' | python3.12
+{% endif %}
+
 # Enable Git Large File Storage (LFS) support
 RUN git lfs install

src/ue4docker/dockerfiles/ue4-minimal/linux/Dockerfile

@@ -49,6 +49,9 @@ RUN ./Engine/Build/BatchFiles/RunUAT.sh BuildGraph \
 COPY split-components.py /tmp/split-components.py
 RUN python3 /tmp/split-components.py /home/ue4/UnrealEngine/LocalBuilds/Engine/Linux /home/ue4/UnrealEngine/Components
 
+# Ensure UnrealVersionSelector is built, since the prebuilt binaries may not be up-to-date
+RUN ./Engine/Build/BatchFiles/Linux/Build.sh UnrealVersionSelector Linux Shipping
+
 # Copy InstalledBuild.txt from the Installed Build and run UnrealVersionSelector to populate Install.ini with any custom Build ID specified in the BuildGraph flags
 # (Note that the `-unattended` flag used below requires Unreal Engine 4.22 or newer, so this will break under older versions)
 # (Note also that custom Build IDs are supported by Unreal Engine 5.3.1 and newer, and older versions will just use a GUID as the Build ID)
@@ -72,6 +75,13 @@ COPY --chown=ue4:ue4 copy-toolchain.py /tmp/copy-toolchain.py
 RUN python3 /tmp/copy-toolchain.py /home/ue4/UnrealEngine
 {% endif %}
 
+{% if enable_ushell %}
+# Ensure ushell is copied to the Installed Build
+RUN rm -rf ./LocalBuilds/Engine/Linux/Engine/Extras/ushell && \
+	cp -r ./Engine/Extras/ushell ./LocalBuilds/Engine/Linux/Engine/Extras/ushell && \
+	bash -c 'set -e; shopt -s globstar; cd /home/ue4/UnrealEngine/LocalBuilds/Engine/Linux/Engine/Extras/ushell && chmod +x ./**/*.sh'
+{% endif %}
+
 # Copy the Installed Build into a clean image, discarding the source build
 {% if combine %}
 FROM prerequisites as minimal
@@ -103,6 +113,15 @@ LABEL com.adamrehn.ue4-docker.excluded.debug={% if excluded_components.debug ==
 LABEL com.adamrehn.ue4-docker.excluded.templates={% if excluded_components.templates == true %}1{% else %}0{% endif %} 
 {% endif %}
 
+{% if enable_ushell %}
+# Add ushell to the system PATH and alias `ushell` to `ushell.sh`
+ENV PATH="$PATH:/home/ue4/UnrealEngine/Engine/Extras/ushell"
+RUN echo 'alias ushell="ushell.sh"' >> /home/ue4/.bashrc
+
+# Perform first-run setup for ushell
+RUN bash -c 'set -e; source /home/ue4/UnrealEngine/Engine/Extras/ushell/ushell.sh && exit 0'
+{% endif %}
+
 # Perform first-run setup for Mono, UnrealBuildTool and AutomationTool, which makes it possible to build Unreal projects and plugins as users other than `ue4`
 # (Note that this will only work with 4.26.0 and newer, older Engine versions will always require write access to `/home/ue4/UnrealEngine`)
 # See the comments on this issue for details, including the need to ensure $HOME is set correctly: <https://github.com/adamrehn/ue4-docker/issues/141>