I was thinking about future of Mock and I would like to share my thought with you:
* This year will be EOLed RHEL5. Despite that I would like to keep RHEL5 configs for maybe an additional year. I.e.
support RHEL5 as build target.
* On the other hand - I'm thinking about ending support for RHEL6 as host platform. I.e. no longer build new mock
version for RHEL6. But still have RHEL6 config, so users can build their SRPM for RHEL6. This will allow me to get rid
of some compatibility workarounds and use --new-chroot everywhere (as RHEL6 does not have systemd-nspawn).
* Make --new-chroot default. Did you tested it? Do you have cases when it does not work? Please report it. I plan to
keep --old-chroot option for some time (definitely for this year).
* Check gpg signatures in rawhide. See https://pagure.io/releng/issue/6600
I welcome any comments.
I just released new version of Mock.
I submitted it to updates-testing F26, F25 and EPEL-7 so please test it
before it hit stable.
From the release notes:
There are new features:
* Mock previously used chroot technology. Few past releases Mock offered
systemd-nspawn which is modern container technology for better
isolation. This release use systemd-nspawn as default. If you want to
preserve previous behaviour you can use `--old-chroot` option.
* Mock now uses bootstrap chroot to install target chroot. This is big
change and see special paragraph at the bottom of this release notes.
* Chroot now contains `/dev/hwrng` and `/dev/prandom` when they exists
in host [[#33](https://github.com/rpm-software-management/mock/issues/33)]
* We added %distro_section macro to Mageia configs
There are some bugfixes:
* Resultdir is now chowned to user who executed mock so they can delete
* Previously we declared that package state plugin is enabled by
default, but the plugin was in fact disabled. It is now enabled by
default (as stated in mock documentation)
* Creating directories for mount points have been delayed after mount of
* Exit code of machinectl is now ignored as machinectl set non-zero code
even for non-fatal errors. Errors which are quite often not relevant nor
important for mock.
* hw_info plugin does not crash when output contains non-ASCII
* This version has not been released for EL6. If you are using EL6 and
you want to use latest Mock, please upgrade you infrastructure to EL7.
* Configs for s390 architecture has been removed as it is not supported
* Configs for aarch64 and ppc64le now use different GPG key as those
architectures has been moved from Secondary to Primary.
* Epel5 config points now to Vault.centos.org. Note that EL5 has been
EOLed. We will keep epel-5 config for some time. But any issue with
building for epel-5 target will not be fixed.
## Bootstrap chroot
Mock is calling `dnf --installroot` to install packages for target
architecture into target directory. This works. Mostly. The only problem
that use host DNF and rpm to install packages. But this can cause
problem when new RPM feature is introduces. Like Soft dependencies or
Rich dependencies. When you have EL6 host and try to install Fedora
rawhide package with Rich dependency then rpm will fail and you cannot
do anything about it. You can upgrade your build machine to Fedora
rawhide, but that is often not possible when it is part of critical
So we introduced Boostrap chroot. And 'we' actually means Michael Cullen
who implement it. And Igor Gnatenko who proposed this idea. Big kudos
for both of them.
Bootstrap chroot means that we first create very minimal chroot for
target platform and we call DNF/YUM from that platform. For example:
when you are on RHEL7 and you want to build package for
`fedora-26-x86_64`, mock will first create chroot called
`fedora-26-x86_64-bootstrap`, it will install DNF and rpm there (fc26
versions). Then it will call DNF from `fedora-26-x86_64-bootstrap` to
install all needed packages to `fedora-26-x86_64` chroot.
The disadvantage is that you will need more storage in `/var/lib/mock`,
the build is little bit slower. But you will hardly notice that unless
you disabled `yum_cache` and `root_cache` plugins for some reasons.
The advantage is that you can use stable version of OS to build packages
for even most recent OS. And vice versa.
If you want to preserve previous behaviour you can use
`--no-bootstrap-chroot` command line option or set:
config_opts['use_bootstrap_container'] = False
in your configuration.
Miroslav Suchy, RHCA
Red Hat, Senior Software Engineer, #brno, #devexp, #fedora-buildsys