ubuntu 18.04 has nginx 1.14
ubuntu 20.04, 22.04 has nginx 1.18
We used a custom nginx for TLSv1.3 support (ssl_protocols TLSv1.3).
OpenSSL itself has TLS 1.3 only from Ubuntu 18.10. This is why we
installed custom packages on Ubuntu 18.04
the baseimage directory was from a time when we used to build a
base image and snapshot it. this is not done anymore.
init-ubuntu.sh - static packages installed one time and managed by ubuntu
installer.sh - packages installed and maintained by cloudron. run before an update.
this can "fail" and the updater can thus abort
start.sh - configuring packages
