Update Dockerfile for Ubuntu

Signed-off-by: Martin Hoffmann <[email protected]>
Change-Id: I5467d8d7a89a583eaeb8a782bc35c5f0a85c6d72

docker/from-source/Ubuntu

@@ -2,7 +2,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 # refresh repos otherwise installations later may fail
 # install LibreOffice run-time dependencies
@@ -16,7 +16,7 @@ RUN apt-get update && \
                libcap2-bin openssl openssh-client inotify-tools procps \
                libxcb-shm0 libxcb-render0 libxrender1 libxext6 \
                fonts-wqy-zenhei fonts-wqy-microhei fonts-droid-fallback \
-               fonts-noto-cjk
+               fonts-noto-cjk ca-certificates
 
 # copy freshly built LOKit and Collabora Online
 COPY /instdir /
@@ -40,6 +40,6 @@ RUN setcap cap_fowner,cap_chown,cap_sys_chroot=ep /usr/bin/coolforkit-caps && \
 EXPOSE 9980
 
 # switch to cool user (use numeric user id to be compatible with Kubernetes Pod Security Policies)
-USER 101
+USER 100
 
 CMD ["/start-collabora-online.sh"]