mkvm: Add script to create FCOS VM

Fedora CoreOS can be provisioned on a QEMU virtual machine by providing
the Ignition configuration via `fw_cfg` value.  Unfortunately, the
`string` method does not work with JSON values, so we have to use
`file`.  The configuration file has to be uploaded via SFTP, rather than
`virsh vol-import`, since the latter would create the file with the
wrong permissions, and QEMU does not automatically adjust the
permissions of files used this way (like it does for disks).

Makefile

@@ -1,7 +1,8 @@
 .PHONY: \
 	all \
 	clean \
-	publish
+	publish \
+	vm
 
 .DEFAULT_GOAL := all
 
@@ -26,3 +27,7 @@ $(foreach t,$(wildcard *.yaml),$(eval $(call genrules,$(t))))
 publish: \
 		nvr1.ign
 	rsync -rti $^ files.pyrocufflink.blue:public_html/
+
+vm: \
+		$(VMNAME).ign
+	sh mkvm.sh $(VMNAME)

mkvm.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+# vim: set sw=4 ts=4 sts=4 et :
+
+: "${POOL:=default}"
+: "${VCPUS:=2}"
+: "${MEMORY:=2048}"
+: "${DISK_SIZE:=10}"
+: "${NETWORK=network=prod}"
+
+VMNAME="$1"
+
+pooldir=$(virsh pool-dumpxml "${POOL}" | xmllint --xpath '//path/text()' -)
+
+vmhost=$(virsh uri | cut -d/ -f3)
+ign="${pooldir}/${VMNAME}.ign"
+if [ -n "${vmhost}" ]; then
+    scp -s "${VMNAME}".ign "${vmhost}:${ign}"
+else
+    cp "${VMNAME}".ign "${ign}"
+fi
+
+image=$(virsh vol-list "${POOL}" \
+    | awk '/fedora-coreos-.*-qemu/{print $2}' \
+    | sort -V \
+    | tail -n1)
+
+virt-install \
+    --name "${VMNAME}" \
+    --vcpus "${VCPUS}" \
+    --memory "${MEMORY}" \
+    --os-variant fedora-coreos-stable \
+    --graphics none \
+    --sound none \
+    --disk size="${DISK_SIZE},backing_store=${image}" \
+    ${DISK:+--disk "${DISK}"} \
+    --network "${NETWORK}" \
+    --qemu-commandline="--fw_cfg name=opt/com.coreos/config,file=${ign}" \
+    --import
+