kola/tests: add /var/lib/containers to separate disk test

Customers have requested the ability to use a separate disk for
/var/lib/containers as a day two operation.  This is a sanity
test that makes sure this can be done with systemd units as
described in the knowlege base article [0].

[0] https://access.redhat.com/solutions/4952011

mantle/kola/tests/rhcos/disk.go

@@ -0,0 +1,148 @@
+// Copyright 2020 Red Hat, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rhcos
+
+import (
+	"encoding/json"
+	"fmt"
+
+	ignconverter "github.com/coreos/ign-converter"
+	ignv3types "github.com/coreos/ignition/v2/config/v3_0/types"
+	"github.com/coreos/mantle/kola/cluster"
+	"github.com/coreos/mantle/kola/register"
+	"github.com/coreos/mantle/platform"
+	"github.com/coreos/mantle/platform/conf"
+	"github.com/coreos/mantle/platform/machine/unprivqemu"
+	"github.com/coreos/mantle/util"
+)
+
+func init() {
+	register.RegisterTest(&register.Test{
+		Run:         varLibContainers,
+		ClusterSize: 0,
+		Name:        `rhcos.disk.varlibcontainers`,
+		Flags:       []register.Flag{},
+		Distros:     []string{"rhcos"},
+		Platforms:   []string{"qemu-unpriv"},
+	})
+}
+
+func varLibContainers(c cluster.TestCluster) {
+	var m platform.Machine
+	var err error
+	disk := "secondary"
+	varMountName := "var-lib-containers.mount"
+	mkfsServiceName := fmt.Sprintf("systemd-mkfs@dev-disk-by-id-virtio-%s.service", disk)
+
+	options := platform.MachineOptions{
+		AdditionalDisks: []platform.Disk{
+			{Size: "1024M", DeviceOpts: []string{"serial=secondary"}},
+		},
+	}
+
+	mkfsUnit := fmt.Sprintf(`[Unit]
+	Description=Make File System on /dev/disk/by-id/%[1]s
+	DefaultDependencies=no
+	BindsTo=dev-disk-by\x2did-virtio\x2d%[1]s.device
+	After=dev-disk-by\x2did-virtio\x2d%[1]s.device var.mount
+	Before=systemd-fsck@dev-disk-by\x2did-virtio\x2d%[1]s.service
+	Before=shutdown.target
+
+	[Service]
+	Type=oneshot
+	RemainAfterExit=yes
+	ExecStart=/bin/bash -c "/bin/rm -rf /var/lib/containers/*"
+	ExecStart=mkfs.xfs /dev/disk/by-id/virtio-%[1]s
+	TimeoutSec=0
+
+	[Install]
+	WantedBy=var-lib-containers.mount`, disk)
+
+	varMountUnit := fmt.Sprintf(`[Unit]
+	Description=Mount secondary disk to /var/lib/containers
+	Before=local-fs.target
+	Requires=%[1]s
+	After=%[1]s
+
+	[Mount]
+	What=/dev/disk/by-id/virtio-%[2]s
+	Where=/var/lib/containers
+	Type=xfs
+	Options=defaults,prjquota
+
+	[Install]
+	WantedBy=local-fs.target`, mkfsServiceName, disk)
+
+	config := ignv3types.Config{
+		Ignition: ignv3types.Ignition{
+			Version: "3.0.0",
+		},
+		Systemd: ignv3types.Systemd{
+			Units: []ignv3types.Unit{
+				{
+					Name:     mkfsServiceName,
+					Contents: &mkfsUnit,
+					Enabled:  util.BoolToPtr(true),
+				},
+				{
+					Name:     varMountName,
+					Contents: &varMountUnit,
+					Enabled:  util.BoolToPtr(false),
+				},
+			},
+		},
+	}
+	convertedConf, err := ignconverter.Translate3to2(config)
+	buf, err := json.Marshal(convertedConf)
+	if err != nil {
+		c.Fatalf("Unable to Marshal config")
+	}
+	serializedConfig := buf
+
+	switch pc := c.Cluster.(type) {
+	// These cases have to be separated because when put together to the same case statement
+	// the golang compiler no longer checks that the individual types in the case have the
+	// NewMachineWithOptions function, but rather whether platform.Cluster does which fails
+	case *unprivqemu.Cluster:
+		m, err = pc.NewMachineWithOptions(conf.Ignition(string(serializedConfig)), options, true)
+	default:
+		c.Fatal("unknown cluster type")
+	}
+
+	if err != nil {
+		c.Fatal(err)
+	}
+
+	// Verify /var/lib/containers isn't mounted then enable the units to move
+	// it to the secondary disk
+	vlc := "/var/lib/containers"
+	if mount, err := c.SSH(m, fmt.Sprintf("findmnt %s -n -o SOURCE", vlc)); err == nil {
+		c.Fatalf("%s is already mounted on %s", vlc, string(mount))
+	}
+	c.MustSSH(m, "podman run docker.io/hello-world")
+	c.MustSSH(m, fmt.Sprintf("sudo systemctl enable %s", mkfsServiceName))
+	c.MustSSH(m, fmt.Sprintf("sudo systemctl enable %s", varMountName))
+	if err := m.Reboot(); err != nil {
+		c.Fatal("Unable to reboot")
+	}
+
+	// Verify /var/lib/containers is now mounted on the secondary disk
+	secondaryDisk := c.MustSSH(m, fmt.Sprintf("readlink -f /dev/disk/by-id/virtio-%s", disk))
+	mount := c.MustSSH(m, fmt.Sprintf("findmnt %s -n -o SOURCE", vlc))
+	if string(secondaryDisk) != string(mount) {
+		c.Fatalf("%s is not mounted on %s", vlc, secondaryDisk)
+	}
+	c.MustSSH(m, "podman run docker.io/hello-world")
+}