2.4. Understanding the UBI init images
The UBI init images, named ubi-init, contain the systemd initialization system, making them useful for building images in which you want to run systemd services, such as a web server or file server. The init image contains more content than minimal images but less than standard images.
Because the ubi10-init image builds on top of the ubi10 image, their contents are mostly the same. However, there are a few critical differences:
ubi10-init:-
CMD is set to
/sbin/initto start thesystemdInit service by default -
includes
psand process related commands (procps-ngpackage) -
sets
SIGRTMIN+3as theStopSignal, assystemdinubi10-initignores normal signals to exit (SIGTERMandSIGKILL), but will terminate if it receivesSIGRTMIN+3
-
CMD is set to
ubi10:-
CMD is set to
/bin/bash -
does not include
psand process related commands (procps-ngpackage) -
does not ignore normal signals to exit (
SIGTERMandSIGKILL)
-
CMD is set to