tests/kola: refactor kernel-replace to build containers first

Factor out the container building into their own functions and
create both container images on the first boot so we know earlier
if the `podman build` with the kernel replace fails.

tests/kola/rpm-ostree/kernel-replace

@@ -45,41 +45,13 @@ cd $(mktemp -d)
 OS_ID=$(. /etc/os-release; echo $ID)
 imagepath=/var/tmp/coreos.ociarchive
 imagespec="oci-archive:${imagepath}"
+derived_imagepath=/var/tmp/coreos-derived.ociarchive
+derived_imagespec="oci-archive:${derived_imagepath}"
 arch=$(arch)
 
-# we only want to query repos once but need the info on multiple boots, so write out state to /var
-if [ ! -f /var/kola-kernel.evr ]; then
-  case "$OS_ID" in
-    rhcos|scos|rhel|centos)
-      c9s_mirror="https://mirror.stream.centos.org/9-stream/BaseOS/${arch}/os"
-      # we're probably already on CentOS and running the latest kernel. so
-      # here we need to instead pick whatever the latest that's *not* the same
-      kver=$(dnf repoquery kernel --qf '%{EVR}' --repofrompath=tmp,"${c9s_mirror}" --disablerepo '*' --enablerepo tmp | \
-                grep -v "$(rpm -q kernel --qf '%{EVR}')" | tail -n1)
-      kver="${kver}.${arch}"
-      url="${c9s_mirror}/Packages/kernel"
-      ;;
-    fedora)
-      # to get the version to use: koji latest-pkg f40 kernel
-      # XXX: once we can rely on dnf in FCOS, use repoquery also here
-      kver="6.8.5-301.fc40.${arch}"
-      url="https://kojipkgs.fedoraproject.org//packages/kernel/6.8.5/301.fc40/${arch}/kernel"
-      ;;
-    *)
-      echo "Unknown OS_ID: ${OS_ID}"
-      exit 1
-      ;;
-  esac
-  echo "$kver" > /var/kola-kernel.evr
-  echo "$url" > /var/kola-kernel.url
-else
-  kver=$(cat /var/kola-kernel.evr)
-  url=$(cat /var/kola-kernel.url)
-fi
 
-case "${AUTOPKGTEST_REBOOT_MARK:-}" in
-  "")
-    # Take the existing ostree commit, and export it to a container image, then rebase to it.
+build_base_ociarchive() {
+    # Take the existing ostree commit, and export it to a container image/ociarchive
     rpm-ostree status --json > status.json
     checksum=$(jq -r '.deployments[0].checksum' < status.json)
     v0=$(jq -r '.deployments[0].version' < status.json)
@@ -96,27 +68,73 @@ case "${AUTOPKGTEST_REBOOT_MARK:-}" in
     # Since we're switching OS update stream, turn off zincati
     systemctl mask --now zincati
     ostree container encapsulate "${encapsulate_args[@]}" --repo=/ostree/repo ${checksum} "${imagespec}"
-    # This one keeps --experimental, but we also test without it below
-    rpm-ostree rebase --experimental "ostree-unverified-image:${imagespec}"
-    ostree container image list --repo=/ostree/repo | tee imglist.txt
-    # Test rebasing back to ostree https://github.com/coreos/rpm-ostree/issues/3677
-    rpm-ostree rebase "$checksum"
-    rpm-ostree rebase "ostree-unverified-image:${imagespec}"
-    /tmp/autopkgtest-reboot 1
-    ;;
-  1)
+}
+
+build_derived_ociarchive() {
+    # we only want to query repos once but need the info on multiple boots, so write out state to /var
+    if [ ! -f /var/kola-kernel.evr ]; then
+      case "$OS_ID" in
+        rhcos|scos|rhel|centos)
+          c9s_mirror="https://mirror.stream.centos.org/9-stream/BaseOS/${arch}/os"
+          # we're probably already on CentOS and running the latest kernel. so
+          # here we need to instead pick whatever the latest that's *not* the same
+          kver=$(dnf repoquery kernel --qf '%{EVR}' --repofrompath=tmp,"${c9s_mirror}" --disablerepo '*' --enablerepo tmp | \
+                    grep -v "$(rpm -q kernel --qf '%{EVR}')" | tail -n1)
+          kver="${kver}.${arch}"
+          url="${c9s_mirror}/Packages/kernel"
+          ;;
+        fedora)
+          # to get the version to use: koji latest-pkg f40 kernel
+          # XXX: once we can rely on dnf in FCOS, use repoquery also here
+          kver="6.8.5-301.fc40.${arch}"
+          url="https://kojipkgs.fedoraproject.org//packages/kernel/6.8.5/301.fc40/${arch}/kernel"
+          ;;
+        *)
+          echo "Unknown OS_ID: ${OS_ID}"
+          exit 1
+          ;;
+      esac
+      echo "$kver" > /var/kola-kernel.evr
+      echo "$url" > /var/kola-kernel.url
+    else
+      kver=$(cat /var/kola-kernel.evr)
+      url=$(cat /var/kola-kernel.url)
+    fi
+
     td=$(mktemp -d)
-    cd ${td}
+    pushd ${td}
     cat > Containerfile << EOF
 FROM $imagespec
 RUN rpm-ostree override replace \
     $url-{,core-,modules-,modules-core-,modules-extra-}$kver.rpm && \
     rpm-ostree cleanup -m && \
     ostree container commit
 EOF
-    derived_imagepath=/var/tmp/coreos-derived.ociarchive
-    derived_imagespec="oci-archive:${derived_imagepath}"
     podman build --net=host -t "${derived_imagespec}" --squash .
+    popd
+}
+
+case "${AUTOPKGTEST_REBOOT_MARK:-}" in
+  "")
+    # First thing, let's create the base and derived OCI archive image files
+    build_base_ociarchive
+    build_derived_ociarchive
+
+    # Since we're switching OS update streams, turn off zincati
+    systemctl mask --now zincati
+
+    # Rebase a few times to test the mechanisms
+    #
+    # This one keeps --experimental, but we also test without it below
+    rpm-ostree rebase --experimental "ostree-unverified-image:${imagespec}"
+    ostree container image list --repo=/ostree/repo | tee imglist.txt
+    # Test rebasing back to ostree https://github.com/coreos/rpm-ostree/issues/3677
+    rpm-ostree rebase "$checksum"
+    rpm-ostree rebase "ostree-unverified-image:${imagespec}"
+    /tmp/autopkgtest-reboot 1
+    ;;
+  1)
+    # Now test rebasing to the derived kernel-replaced image
     rpm-ostree --version
     rpm-ostree rebase "ostree-unverified-image:$derived_imagespec"
     ostree container image list --repo=/ostree/repo