These Docker images allow you to very easily build a Qt app accross all platforms. You may use build system (e.g. Gitlab CI) to fully leverage these images.

Qt toolchain Docker images

Qt 6.3.2 (EOL 2023-04-12)

• a12e/docker-qt:6.3-linux (Ubuntu 18.04 LTS, GCC 11.1, CMake 3.24.2, linuxdeployqt)

Qt 6.4.3 (EOL 2023-09-29)

• a12e/docker-qt:6.4-android (Ubuntu 22.04 LTS, CMake 3.24.2, OpenSSL 1.1.1t)
• a12e/docker-qt:6.4-linux (Ubuntu 18.04 LTS, GCC 11.1, CMake 3.24.2, linuxdeployqt)

Qt 6.5.3 LTS

• a12e/docker-qt:6.5-android (Ubuntu 22.04 LTS, CMake 3.27.7, OpenSSL 3.0.11)
• a12e/docker-qt:6.5-linux (Ubuntu 20.04 LTS, GCC 11.1, CMake 3.27.7, linuxdeployqt)

Android example

docker run -it --rm --volume $PWD:/src a12e/docker-qt:6.5-android

mkdir ~/build && cd ~/build
qt-cmake /src -DQT_ANDROID_BUILD_ALL_ABIS=YES
cmake --build . --target aab

Linux example

docker run -it --rm --volume $PWD:/src a12e/docker-qt:6.5-linux

mkdir ~/build && cd ~/build
cmake /src
cmake --build . --parallel
cmake --install . --prefix $PWD/appdir/usr
linuxdeployqt appdir/usr/share/applications/*.desktop -appimage -qmldir=/src/resources/ -extra-plugins=platforms

Notes

OpenSSL for Android is compiled and installed directly inside the Qt directory, so you can easily link to or ship it:

find_package(OpenSSL 1.1 REQUIRED)
get_filename_component(OPENSSL_LIB_DIR ${OPENSSL_SSL_LIBRARY} DIRECTORY)
# To make androiddeployqt deploy OpenSSL (mandatory)
# Use _1_1.so suffix instead of _3.so for OpenSSL 1.1 on Qt <= 6.4
set_property(TARGET MyTarget
    APPEND PROPERTY QT_ANDROID_EXTRA_LIBS
    ${OPENSSL_LIB_DIR}/libcrypto_3.so
    ${OPENSSL_LIB_DIR}/libssl_3.so
)
# To use crypto in your app (optional)
target_link_libraries(MyTarget PRIVATE
    OpenSSL::Crypto
)

Linux images are built inside a 20.04 LTS Ubuntu, to allow the AppImage to be run on older systems. Otherwise, links to too recent versions of the glibc are made.