In the case we are not using a buildroot (i.e. we are using
the host as the buildroot) let's also mount in /etc/containers
into the environment. There are sometimes where software running
from /usr can't operate without configuration in /etc and this
will allow it to work.
An example of software hitting this problem is skopeo. With a
simple config like:
```
version: '2'
mpp-vars:
release: 38
pipelines:
- name: skopeo-tree
# build: name:build
source-epoch: 1659397331
stages:
- type: org.osbuild.skopeo
inputs:
images:
type: org.osbuild.containers
origin: org.osbuild.source
mpp-resolve-images:
images:
- source: quay.io/fedora/fedora-coreos
tag: stable
name: localhost/fcos
options:
destination:
type: containers-storage
storage-path: /usr/share/containers/storage
```
We end up hitting an error like this:
```
time="2023-10-24T18:27:14Z" level=fatal msg="Error loading trust policy: open /etc/containers/policy.json: no such file or directory"
Traceback (most recent call last):
File "/run/osbuild/bin/org.osbuild.skopeo", line 90, in <module>
r = main(args["inputs"], args["tree"], args["options"])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/run/osbuild/bin/org.osbuild.skopeo", line 73, in main
subprocess.run(["skopeo", "copy", image_source, dest], check=True)
File "/usr/lib64/python3.11/subprocess.py", line 571, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['skopeo', 'copy', 'dir:/tmp/tmp5_qcng99/image', 'containers-storage:[overlay@/run/osbuild/tree/usr/share/containers/storage+/run/containers/storage]localhost/fcos']' returned non-zero exit status 1.
```
This PR adds in a mount for /etc/containers from the host so that
/etc/containers/policy.json can be accessed.
d4b3e3655d