Fedora CoreOS support (#5657)

* fedora coreos support
- bootstrap and new fact for

* fedora coreos support
- fix bootstrap condition

* fedora coreos support
- allow customize packages for fedora coreos bootstrap

* fedora coreos support
- prevent install ptyhon3 and epel via dnf for fedora coreos

* fedora coreos support
- handle all ostree like os in same way

* fedora coreos support
- handle all ostree like os in same way for crio

* fedora coreos support
- add fcos documentations

docs/fcos.md

@@ -0,0 +1,76 @@
+# Fedora CoreOS
+
+Tested with stable version 31.20200223.3.0
+Because package installation with `rpm-ostree` requires a reboot, playbook may fail while bootstrap.
+Restart playbook again.
+
+## Containers
+
+Tested with
+
+- docker
+- crio
+
+### docker
+
+OS base packages contains docker.
+
+### cri-o
+
+To use `cri-o` disable docker service with ignition:
+
+```yaml
+#workaround, see https://github.com/coreos/fedora-coreos-tracker/issues/229
+systemd:
+  units:
+    - name: docker.service
+      enabled: false
+      contents: |
+        [Unit]
+        Description=disable docker
+
+        [Service]
+
+        [Install]
+        WantedBy=multi-user.target
+```
+
+## libvirt setup
+
+### Prepare
+
+Prepare ignition and serve via http (a.e. python -m SimpleHTTPServer )
+
+```json
+{
+  "ignition": {
+     "version": "3.0.0"
+  },
+
+  "passwd": {
+    "users": [
+      {
+        "name": "adi",
+        "passwordHash": "$1$.RGu8J4x$U7uxcOg/eotTEIRxhk62I0",
+        "sshAuthorizedKeys": [
+          "ssh-rsa ..fillyouruser"
+        ],
+        "groups": [ "wheel" ]
+      }
+    ]
+  }
+}
+```
+
+### create guest
+
+```shell script
+fcos_version=31.20200223.3.0
+kernel=https://builds.coreos.fedoraproject.org/prod/streams/stable/builds/${fcos_version}/x86_64/fedora-coreos-${fcos_version}-live-kernel-x86_64
+initrd=https://builds.coreos.fedoraproject.org/prod/streams/stable/builds/${fcos_version}/x86_64/fedora-coreos-${fcos_version}-live-initramfs.x86_64.img
+ignition_url=http://mywebserver/fcos.ign
+kernel_args="ip=dhcp rd.neednet=1 console=tty0 coreos.liveiso=/ console=ttyS0 coreos.inst.install_dev=/dev/sda coreos.inst.stream=stable coreos.inst.ignition_url=${ignition_url}"
+sudo virt-install --name ${machine_name} --ram 4048 --graphics=none --vcpus 2 --disk size=20 \
+                --network bridge=virbr0 \
+                --install kernel=${kernel},initrd=${initrd},kernel_args_overwrite=yes,kernel_args="${kernel_args}"
+```