Core20 snap for snapd
This is a base snap for snapd that is based on Ubuntu 20.04
Building locally
To build this snap locally you need snapcraft. The project must be built as real root.
$ sudo snapcraft
Writing code
The usual way to add functionality is to write a shell script hook
with the .chroot extenstion under the hooks/ directory. These hooks
are run inside the base image filesystem.
Each hook should have a matching .test file in the hook-tests
directory. Those tests files are run relative to the base image
filesystem and should validates that the coresponding .chroot file
worked as expected.
The .test scripts will be run after building with snapcraft or when
doing a manual "make test" in the source tree.
Bootchart
It is possible to enable bootcharts by adding
core.bootchart to the kernel command
line. The sample collector will run until the system is seeded (it will
stop when the snapd.seeded.service stops). The bootchart will be saved
in the ubuntu-save partition, under log/boot<N>/, being <N> the
boot number since bootcharts were enabled. If a chart has been collected
by the initramfs, it will be also saved in that folder.
TODO In the future, we would want systemd-bootchart to be started
only from the initramfs and have just one bootchart per boot. However,
this is currently not possible as systemd-bootchart needs some changes
so it can survive the switch root between initramfs and data
partition. With those changes, we could also have systemd-bootchart as
init process so we get an even more accurate picture.