dracut: add hetzner cloud support

dracut/30ignition/coreos-hcloud-hostname.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=CoreOS Hetzner Cloud Hostname Agent
+DefaultDependencies=false
+Before=initrd.target
+After=systemd-networkd.service initrd-root-fs.target
+Wants=systemd-networkd.service initrd-root-fs.target
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/coreos-metadata --cmdline --hostname=/sysroot/etc/hostname

dracut/30ignition/ignition-generator

@@ -97,6 +97,10 @@ if [[ $(cmdline_arg coreos.oem.id) == "digitalocean" ]]; then
     add_requires coreos-digitalocean-network.service
 fi
 
+if [[ $(cmdline_arg coreos.oem.id) == "hcloud" ]]; then
+    add_requires coreos-hcloud-hostname.service
+fi
+
 oem_id=pxe
 if [[ $(systemd-detect-virt || true) =~ ^(kvm|qemu)$ ]]; then
     oem_id=qemu

dracut/30ignition/module-setup.sh

@@ -49,6 +49,9 @@ install() {
     inst_simple "$moddir/coreos-digitalocean-network.service" \
         "$systemdsystemunitdir/coreos-digitalocean-network.service"
 
+    inst_simple "$moddir/coreos-hcloud-hostname.service" \
+        "$systemdsystemunitdir/coreos-hcloud-hostname.service"    
+
     inst_simple "$moddir/coreos-static-network.service" \
         "$systemdsystemunitdir/coreos-static-network.service"