Fix storage.conf setup in test-system

- Don't do it at all for the CI VM: We can use the
  VM's global Podman configuration, and use faster overlay
  instead of vfs, so let's do that.
- For the developer-run (make test-system):
  - Add graphroot and runroot paths to make the configuration minimally valid
  - Explicitly point CONTAINERS_STORAGE_CONF at the configutation
    to be certain it will get used.

Then drop the (podman pull ...) in runner.sh:_podman_reset that seemed to
previously workaround the invalid /etc/containers/storage.conf .

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

contrib/cirrus/runner.sh

@@ -115,15 +115,6 @@ _run_unit() {
 _podman_reset() {
     # Ensure we start with a clean-slate
     showrun podman system reset --force
-    # WARNING WARNING WARNING WARNING
-    # Without running a container, the system tests will inexplicably
-    # fail with obscure errors/warning messages.  I have no idea why
-    # running a container after a `system reset` fixes/prevents the
-    # problem.  The failures do not reproduce when tests are run manually.
-    # So unless or until /until somebody develops a better understanding,
-    # this fix is JFM - just fakking magic.
-    # WARNING WARNING WARNING WARNING
-    showrun podman run -it --rm --entrypoint /bin/true quay.io/libpod/alpine:latest
 }
 
 _run_integration() {

hack/make/test-system

@@ -5,17 +5,37 @@ set -e
 # not all storage drivers are supported in a container
 # environment.  Detect this and setup storage when
 # running in a container.
-if ((SKOPEO_CONTAINER_TESTS)) && [[ -r /etc/containers/storage.conf ]]; then
+#
+# Paradoxically (FIXME: clean this up), SKOPEO_CONTAINER_TESTS is set
+# both inside a container and without a container (in a CI VM); it actually means
+# "it is safe to desctructively modify the system for tests".
+#
+# On a CI VM, we can just use Podman as it is already configured; the changes below,
+# to use VFS, are necessary only inside a container, because overlay-inside-overlay
+# does not work. So, make these changes conditional on both
+# SKOPEO_CONTAINER_TESTS (for acceptability to do destructive modification) and !CI
+# (for necessity to adjust for in-container operation)
+if ((SKOPEO_CONTAINER_TESTS)) && [[ "$CI" != true ]]; then
+    if [[ -r /etc/containers/storage.conf ]]; then
+        echo "MODIFYING existing storage.conf"
         sed -i \
             -e 's/^driver\s*=.*/driver = "vfs"/' \
             -e 's/^mountopt/#mountopt/' \
             /etc/containers/storage.conf
-elif ((SKOPEO_CONTAINER_TESTS)); then
+    else
+        echo "CREATING NEW storage.conf"
         cat >> /etc/containers/storage.conf << EOF
 [storage]
 driver = "vfs"
+runroot = "/run/containers/storage"
+graphroot = "/var/lib/containers/storage"
 EOF
     fi
+    # The logic of finding the relevant storage.conf file is convoluted
+    # and in effect differs between Skopeo and Podman, at least in some versions;
+    # explicitly point at the file we want to use to hopefully avoid that.
+    export CONTAINERS_STORAGE_CONF=/etc/containers/storage.conf
+fi
 
 # Build skopeo, install into /usr/bin
 make PREFIX=/usr install