Conditionalize units which require a boot disk

dracut/30ignition/ignition-diskful.target

@@ -0,0 +1,16 @@
+# This target contains Ignition units that should only run when we have a
+# boot disk, i.e. when we're not running diskless from a live image in RAM.
+# Like ignition-complete.target, it only runs on first boot.
+[Unit]
+Description=Ignition Boot Disk Setup
+Before=initrd.target
+
+# Make sure if any ExecStart= fail, the boot fails. This normally would
+# already be guaranteed by `initrd.target` failing, but that doesn't seem to be
+# enough: https://bugzilla.redhat.com/show_bug.cgi?id=1696796
+OnFailure=emergency.target
+OnFailureJobMode=isolate
+
+# Make sure we stop all the units before switching root
+Conflicts=initrd-switch-root.target umount.target
+Conflicts=dracut-emergency.service emergency.service emergency.target

dracut/30ignition/ignition-generator

@@ -37,6 +37,12 @@ add_requires() {
 # boot.
 if $(cmdline_bool 'ignition.firstboot' 0); then
     add_requires ignition-complete.target
+
+    # Invoke distro hook for detecting whether we're booted from a live image,
+    # and therefore won't have a root disk.
+    if ! command -v is-live-image >/dev/null || ! is-live-image; then
+        add_requires ignition-diskful.target
+    fi
 fi
 
 echo "PLATFORM_ID=$(cmdline_arg ignition.platform.id)" > /run/ignition.env

dracut/30ignition/module-setup.sh

@@ -6,12 +6,13 @@ depends() {
     echo qemu systemd url-lib network
 }
 
-# target is optional, used for instantiated units
 install_ignition_unit() {
-    unit=$1; shift
-    target="${1:-$unit}"
+    local unit="$1"; shift
+    local target="${1:-ignition-complete.target}"; shift
+    local instantiated="${1:-$unit}"; shift
     inst_simple "$moddir/$unit" "$systemdsystemunitdir/$unit"
-    ln_r "../$unit" "$systemdsystemunitdir/ignition-complete.target.requires/$target"
+    mkdir -p "$initdir/$systemdsystemunitdir/$target.requires"
+    ln_r "../$unit" "$systemdsystemunitdir/$target.requires/$instantiated"
 }
 
 install() {
@@ -54,16 +55,19 @@ install() {
     inst_simple "$moddir/ignition-complete.target" \
         "$systemdsystemunitdir/ignition-complete.target"
 
-    mkdir -p "$initdir/$systemdsystemunitdir/ignition-complete.target.requires"
+    inst_simple "$moddir/ignition-diskful.target" \
+        "$systemdsystemunitdir/ignition-diskful.target"
 
-    # path generated by systemd-escape --path /dev/disk/by-label/root
-    install_ignition_unit [email protected] 'coreos-gpt-setup@dev-disk-by\x2dlabel-root.service'
     install_ignition_unit ignition-setup-base.service
-    install_ignition_unit ignition-setup-user.service
     install_ignition_unit ignition-disks.service
     install_ignition_unit ignition-mount.service
     install_ignition_unit ignition-files.service
-    install_ignition_unit ignition-remount-sysroot.service
+
+    # units only started when we have a boot disk
+    # path generated by systemd-escape --path /dev/disk/by-label/root
+    install_ignition_unit [email protected]        ignition-diskful.target 'coreos-gpt-setup@dev-disk-by\x2dlabel-root.service'
+    install_ignition_unit ignition-setup-user.service      ignition-diskful.target
+    install_ignition_unit ignition-remount-sysroot.service ignition-diskful.target
 
     # needed for openstack config drive support
     inst_rules 60-cdrom_id.rules

systemd/ignition-firstboot-complete.service

@@ -2,6 +2,7 @@
 Description=Mark boot complete
 Documentation=https://github.com/coreos/ignition
 ConditionKernelCommandLine=ignition.firstboot
+ConditionPathExists=!/run/ostree-live
 RequiresMountsFor=/boot
 
 [Service]