[tracker-oci-images/sam/unprivileged: 2/2] Update Gitlab CI script to run unprivileged

[Sam Thursfield <sthursfield src gnome org>]

commit ad1db202b1958cb1de98d93bda98f8263b34f88d
Author: Sam Thursfield <sam afuera me uk>
Date:   Mon Nov 23 23:49:50 2020 +0100

    Update Gitlab CI script to run unprivileged
    
    Copied from 
https://gitlab.gnome.org/GNOME/librsvg-oci-images/-/commit/c19a8634d51985288c77ad491693f4c62bba6f95
    
    Thanks again to Jordan Petridis!

 .gitlab-ci.yml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e0e529a..de27597 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,11 +1,13 @@
-image: 'registry.fedoraproject.org/fedora:30'
+image: 'registry.fedoraproject.org/fedora:32'
 
 stages:
   - distro
 
 # Buildah can't use 'overlay' driver when running inside docker
 variables:
-  STORAGE_DRIVER: 'vfs'
+  STORAGE_DRIVER: vfs
+  BUILDAH_FORMAT: docker
+  BUILDAH_ISOLATION: chroot
 
 # Expects $IMAGE which should be the name+tag of the registry image.
 # Expects $DOCKERFILE variable which should be the path to the dockerfile
@@ -20,7 +22,7 @@ variables:
     # using the vfs driver, and this causes errors.
     - sed -i '/^mountopt =.*/d' /etc/containers/storage.conf
 
-    - podman build --cgroup-manager=cgroupfs --format=docker --pull -f ${DOCKERFILE} -t ${IMAGE} 
${CONTEXT_DIR}
+    - buildah bud -f ${DOCKERFILE} -t ${IMAGE}
 
     # Show image size.
     - podman image list