Add deploy-via-container and container-imgref keys for image.yaml

This builds on the `image-format: oci` key to switch to using
the new ostree-container code to do the deployment (via rpm-ostree).

Unlike the above though, this is not something we can turn on
by default until we intend to hard cut over to fetching updates
via containers.

The intention is to use this to produce image builds that are
initially provisioned via a container image so that we can more
easily experiment with the "container native" flow.

A side note; I suspect this will indirectly fix
openshift/os#594
because now we're opening a single large file and pulling that
over virtio instead of lots of smaller files.

Author: cgwalters

src/cmd-buildextend-metal

@@ -139,6 +139,12 @@ cat image-default.json "${image_json}" | jq -s add > image-configured.json
 # We do some extra handling of the rootfs here; it feeds into size estimation.
 rootfs_type=$(jq -re .rootfs < image-configured.json)
 
+deploy_container=
+container_imgref=$(jq -r '.["container-imgref"]//""' < image-configured.json)
+if test -n "${container_imgref}" || jq -re '.["deploy-via-container"]' < image-configured.json >/dev/null; then
+    deploy_container=ostree-unverified-image:oci-archive:$builddir/$(meta_key images.ostree.path)
+fi
+
 # fs-verity requires block size = page size. We need to take that into account
 # in the disk size estimation due to higher fragmentation on larger blocks.
 BLKSIZE=""
@@ -204,6 +210,8 @@ cat >image-dynamic.json << EOF
     "osname": "${name}",
     "buildid": "${build}",
     "imgid": "${img}",
+    "deploy-container": "${deploy_container}",
+    "container-imgref": "${container_imgref}",
     "ostree-commit": "${commit}",
     "ostree-ref": "${ref}",
     "ostree-repo": "${ostree_repo}"

src/create_disk.sh

@@ -99,6 +99,8 @@ commit=$(getconfig "ostree-commit")
 ref=$(getconfig "ostree-ref")
 # We support not setting a remote name (used by RHCOS)
 remote_name=$(getconfig_def "ostree-remote" "")
+deploy_container=$(getconfig "deploy-container" "")
+container_imgref=$(getconfig "container-imgref" "")
 os_name=$(getconfig "osname")
 rootfs_size=$(getconfig "rootfs-size")
 buildid=$(getconfig "buildid")
@@ -249,26 +251,45 @@ fi
 ostree admin init-fs --modern $rootfs
 # Initialize the "stateroot"
 ostree admin os-init "$os_name" --sysroot $rootfs
+
+# Propagate flags into target repository
 if [ "${rootfs_type}" = "ext4verity" ]; then
     ostree config --repo=$rootfs/ostree/repo set ex-fsverity.required 'true'
 fi
-time ostree pull-local --repo $rootfs/ostree/repo "$ostree" "$commit"
-if test -n "${remote_name}"; then
-    deploy_ref="${remote_name}:${ref}"
-    ostree refs --repo $rootfs/ostree/repo --create "${deploy_ref}" "${commit}"
-else
-    deploy_ref=$commit
-fi
+
+# Compute kargs
 # Note that $ignition_firstboot is interpreted by grub at boot time,
 # *not* the shell here.  Hence the backslash escape.
 allkargs="$extrakargs \$ignition_firstboot"
-kargsargs=""
-for karg in $allkargs
-do
-	kargsargs+="--karg-append=$karg "
-done
-ostree admin deploy "${deploy_ref}" --sysroot $rootfs --os "$os_name" $kargsargs
 
+if test -n "${deploy_container}"; then
+    kargsargs=""
+    for karg in $allkargs
+    do
+        kargsargs+="--karg=$karg "
+    done
+    rpm-ostree ex-container image deploy --imgref "${deploy_container}" \
+        ${container_imgref:+--target-imgref $container_imgref} \
+        --stateroot "$os_name" --sysroot $rootfs $kargsargs
+else
+    # Pull the commit
+    time ostree pull-local --repo $rootfs/ostree/repo "$ostree" "$commit"
+    # Deploy it, using an optional remote prefix
+    if test -n "${remote_name}"; then
+        deploy_ref="${remote_name}:${ref}"
+        ostree refs --repo $rootfs/ostree/repo --create "${deploy_ref}" "${commit}"
+    else
+        deploy_ref=$commit
+    fi
+    kargsargs=""
+    for karg in $allkargs
+    do
+        kargsargs+="--karg-append=$karg "
+    done
+    ostree admin deploy "${deploy_ref}" --sysroot $rootfs --os "$os_name" $kargsargs
+fi
+# Note that at the current time, this only supports deploying non-layered
+# container images; xref https://github.com/ostreedev/ostree-rs-ext/issues/143
 deploy_root="$rootfs/ostree/deploy/${os_name}/deploy/${commit}.0"
 test -d "${deploy_root}"
 

src/image-default.yaml

@@ -2,3 +2,7 @@
 bootfs: "ext4"
 rootfs: "xfs"
 grub-script: "/usr/lib/coreos-assembler/grub.cfg"
+# True if we should use `rpm-ostree ex-container image deploy`
+deploy-via-container: false
+# Set this to a target container reference, e.g. ostree-unverified-registry:quay.io/example/os:latest
+# container-imgref: ""