kola/tests/misc: add test to verify the DHCP propagation of NTP servers

Writing this test to verify coreos/fedora-coreos-config#412 to enable
the DHCP propagation of NTP servers.This will also avoid any regression
that might cause in RHCOS or FCOS when the upstream changes come down
and obsolete the temporary work.

mantle/kola/tests/misc/chronydhcp.go

@@ -0,0 +1,123 @@
+// Copyright 2020 Red Hat
+//
+// 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 misc
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/coreos/mantle/kola"
+	"github.com/coreos/mantle/kola/cluster"
+	"github.com/coreos/mantle/kola/register"
+	"github.com/coreos/mantle/platform/conf"
+	"github.com/coreos/mantle/util"
+	"github.com/vincent-petithory/dataurl"
+)
+
+var script = []byte(`#!/bin/bash
+# This script creates two veth interfaces i.e. one for the host machine 
+# and other for the container(dnsmasq server). This setup will be helpful
+# to verify the DHCP propagation of NTP servers
+# https://github.com/coreos/fedora-coreos-config/pull/412
+
+set -euo pipefail
+
+# This is needed to run a container with systemd
+setsebool container_manage_cgroup 1
+
+# create a network namespace
+ip netns add container
+
+# create veth pair and assign a namespace to veth-container
+ip link add veth-host type veth peer name veth-container
+ip link set veth-container netns container
+
+# assign an IP address to the 'veth-container' interface and bring it up
+ip netns exec container ip address add 172.16.0.1/24 dev veth-container
+ip netns exec container ip link set veth-container up
+
+# run podman commands to set up dnsmasq server
+cd $(mktemp -d)
+cat <<EOF >Dockerfile
+FROM registry.fedoraproject.org/fedora:32
+RUN dnf -y install systemd dnsmasq iproute iputils
+RUN dnf clean all
+RUN systemctl enable dnsmasq
+RUN echo -e 'dhcp-range=172.16.0.10,172.16.0.20,12h\nbind-interfaces\ninterface=veth-container\ndhcp-option=option:ntp-server,129.6.15.30' > /etc/dnsmasq.d/dhcp
+CMD [ "/sbin/init" ]
+EOF
+podman build -t dnsmasq .
+cd -
+podman run -d --rm --name dnsmasq --privileged --network ns:/var/run/netns/container dnsmasq
+
+# create a static ethernet connection for the 'veth-host'
+nmcli dev set veth-host managed yes
+ip link set veth-host up`)
+
+func init() {
+	register.RegisterTest(&register.Test{
+		Name:        "coreos.chrony.dhcp.verify",
+		Run:         verifyDHCPPropagationOfNTPServers,
+		ClusterSize: 1,
+		Tags:        []string{"chrony", "dhcp", "ntp", kola.NeedsInternetTag},
+		UserDataV3: conf.Ignition(fmt.Sprintf(`{
+			"ignition": {"version": "3.0.0"},
+			"storage": {
+				"files": [
+				  {
+					"group": {},
+					"path": "/usr/local/bin/setup.sh",
+					"user": {},
+					"contents": {
+					  "source": %q,
+					  "verification": {}
+					},
+					"mode": 493
+				  }
+				]
+			  },
+			  "systemd": {
+				"units": [
+				  {
+					"contents": "[Unit]\nDescription=verify chrony using NTP settings from DHCP\n[Service]\nType=oneshot\nExecStart=/usr/local/bin/setup.sh\nRestart=on-failure\nRemainAfterExit=yes\n[Install]\nWantedBy=multi-user.target\n",
+					"enabled": true,
+					"name": "chrony-dhcp.service"
+				  }
+				]
+			  }
+			}`, dataurl.EncodeBytes(script))),
+	})
+}
+
+func verifyDHCPPropagationOfNTPServers(c cluster.TestCluster) {
+	m := c.Machines()[0]
+	// Wait a little bit for the chrony-dhcp.service to start
+	if err := util.WaitUntilReady(10*time.Minute, 5*time.Second, func() (bool, error) {
+		_, _, err := m.SSH("sudo systemctl status chrony-dhcp.service")
+		if err != nil {
+			return false, err
+		}
+		return true, nil
+	}); err != nil {
+		c.Fatal("failed to start chrony-dhcp.service: %v", err)
+	}
+
+	out := c.MustSSH(m, "chronyc sources")
+	// Name: time-c-g.nist.gov  IP address: 129.6.15.30
+	if !strings.Contains(string(out), "time-c-g.nist.gov") {
+		c.Fatalf("propagation of ntp server information via dhcp failed")
+	}
+}