Making an Appimage

Building an Appimage for Qt Application
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When I updated to Ubuntu 24.04 I had an upsetting number of packages break. One of these was AppCSXCAD. It reads OpenEMS XML geometry files and shows them in a GUI. Nothing exciting until you need it. My first move was making sure I could use the Dockerized version in my OpenEMS Docker build here. That needed some attention but it worked in the end. What I really want is an appimage that I can pull down when needed.

After trying to compose one by hand and running into issues with Qt I found a great tool that solved the problem probonopd/linuxdeployqt. It takes care of the tricky parts leaving us with the following Docker image:

FROM openems_base AS builder
ENV DEBIAN_FRONTEND=noninteractive

ARG BRANCH=v0.0.36.alpha2

WORKDIR /root/
RUN git clone --recursive --branch ${BRANCH} https://github.com/snhobbs/OpenEMS-Project.git

# Build all components
WORKDIR /root/OpenEMS-Project/fparser
RUN cmake . && make -j$(nproc) && make install

WORKDIR /root/OpenEMS-Project/CSXCAD
RUN cmake . && make -j$(nproc) && make install

WORKDIR /root/OpenEMS-Project/QCSXCAD
RUN cmake . && make -j$(nproc) && make install

WORKDIR /root/OpenEMS-Project/AppCSXCAD
RUN cmake . && make -j$(nproc) && make install

WORKDIR /root/

RUN apt install wget

RUN wget https://github.com/probonopd/linuxdeployqt/releases/download/continuous/linuxdeployqt-continuous-x86_64.AppImage && \
    chmod 775 linuxdeployqt-continuous-x86_64.AppImage && \
        ./linuxdeployqt-continuous-x86_64.AppImage --appimage-extract && \
            mv squashfs-root/ linuxdeployqt-continuous

RUN mkdir /root/appimage
WORKDIR /root/appimage

RUN convert -size 256x256 xc:white -gravity center \
    -pointsize 24 -annotate 0 "AppCSXCAD" appcsxcad.png

RUN echo '[Desktop Entry]\nType=Application\nName=AppCSXCAD\nExec=AppRun %F\nIcon=appcsxcad\nComment=View and edit OpenEMS Goemetries\nTerminal=true\nCategories=Education;Science;' > default.desktop

# Copy the binary to expected path inside AppDir structure
RUN mkdir -p local/bin && cp /usr/local/bin/AppCSXCAD local/bin

# Use linuxdeploy to populate dependencies (this assumes Qt app)
RUN /root/linuxdeployqt-continuous/AppRun /root/appimage/local/bin/AppCSXCAD -appimage

Once this is built you can copy the generated AppImage by calling:

docker run --name temp-appcsxcad appcsxcad-appimage && 
docker cp temp-appcsxcad:/root/appimage/ ./ ; docker rm temp-appcsxcad

Should make OpenEMS development a bit easier. I’ll make this a github action at some point.

Another useful project: https://github.com/AppImage/AppImageKit/releases/latest/download/appimagetool-x86_64.AppImage