Allow to run buildah from completely unprivileged containers

The current isolation method is working fine on local unprivileged
container, but doesn't seem to be working on unprivileged containers
on kubernetes with CRI-O.

Specifying the chroot isolation method allows to make sure we can run
our scripts in all situations.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
29 jobs for wip/isolation-chroot in 12 minutes and 59 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Bootstrapping
passed #411108
bootstrap

00:03:56

 
  Arch Container Build
passed #411109
arch@container-build

00:01:32

passed #411110
arch-forced@container-ifnot-exists

00:01:51

 
  Arch Check
passed #411111
arch@check

00:00:21

passed #411113
arch@container-ifnot-exists

00:00:23

passed #411112
arch-forced-ifnot-exists@check

00:00:24

 
  Ubuntu Container Build
passed #411116
ubuntu:18.04@container-build

00:01:24

passed #411114
ubuntu:18.10@container-build

00:01:22

passed #411115
ubuntu-forced:18.10@container-ifnot-exists

00:00:25

 
  Ubuntu Check
passed #411120
ubuntu:18.04@check

00:00:24

passed #411117
ubuntu:18.10@check

00:00:15

passed #411119
ubuntu:18.10@container-ifnot-exists

00:00:19

passed #411118
ubuntu:forced-ifnot-exists@check

00:00:20

 
  Debian Container Build
passed #411123
debian:buster@container-build

00:01:10

passed #411122
debian-forced:stretch@container-ifnot-exists

00:00:32

passed #411121
debian:stretch@container-build

00:01:15

 
  Debian Check
passed #411127
debian:buster@check

00:00:21

passed #411125
debian:forced-ifnot-exists@check

00:00:19

passed #411124
debian:stretch@check

00:00:23

passed #411126
debian:stretch@container-ifnot-exists

00:00:20

 
  Fedora Container Build
passed #411128
fedora:29@container-build

00:02:24

passed #411130
fedora-forced:rawhide@container-ifnot-exists

00:00:24

passed #411129
fedora:rawhide@container-build

00:01:56

 
  Fedora Check
passed #411131
fedora:29@check

00:00:21

passed #411135
fedora:29-upstream@container-ifnot-exists

00:00:30

passed #411133
fedora-forced-ifnot-exists:rawhide@check

00:00:19

passed #411132
fedora:rawhide@check

00:00:30

passed #411134
fedora:rawhide@container-ifnot-exists

00:00:25

 
  Container Push
passed #411136
bootstrap-push@push

00:00:19