Metricbeats panics in kvm dommemstat metricset

[adriansr]

For confirmed bugs, please report:

• Version: 6.4.0
• Operating System: Linux
• Discuss Forum URL: https://discuss.elastic.co/t/kvm-module-dial-unknown-network/142062
• Steps to Reproduce:

Enable kvm module:

metricbeat modules enable kvm

Run metricbeat

metricbeat run -N -e -d publish

Results:

2018-07-30T08:32:47.448Z	INFO	pipeline/module.go:98	Beat name: ubuntu-bionic
2018-07-30T08:32:47.451Z	INFO	instance/beat.go:367	metricbeat start running.
2018-07-30T08:32:47.451Z	INFO	[monitoring]	log/log.go:114	Starting metrics logging every 30s
2018-07-30T08:32:47.456Z	WARN	[cfgwarn]	dommemstat/dommemstat.go:67	EXPERIMENTAL: The kvm dommemstat metricset is experimental.
2018-07-30T08:32:47.470Z	INFO	cfgfile/reload.go:140	Config reloader started
2018-07-30T08:32:47.476Z	WARN	[cfgwarn]	dommemstat/dommemstat.go:67	EXPERIMENTAL: The kvm dommemstat metricset is experimental.
2018-07-30T08:32:47.476Z	INFO	cfgfile/reload.go:195	Loading of config files completed.
2018-07-30T08:32:47.481Z	ERROR	runtime/panic.go:63	recovered from panic while fetching 'kvm/dommemstat' for host 'localhost'. Recovering, but please report this.	{"panic": "runtime error: invalid memory address or nil pointer dereference", "stack": "github.com/elastic/beats/libbeat/logp.Recover\n\t/home/vagrant/go/src/github.com/elastic/beats/libbeat/logp/global.go:105\nruntime.call32\n\t/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/asm_amd64.s:573\nruntime.gopanic\n\t/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/panic.go:502\nruntime.panicmem\n\t/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/panic.go:63\nruntime.sigpanic\n\t/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/signal_unix.go:388\ngh.neting.cc/elastic/beats/metricbeat/module/kvm/dommemstat.(*MetricSet).Fetch\n\t/home/vagrant/go/src/github.com/elastic/beats/metricbeat/module/kvm/dommemstat/dommemstat.go:108\ngh.neting.cc/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).fetch\n\t/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:238\ngh.neting.cc/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).startPeriodicFetching\n\t/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:209\ngh.neting.cc/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).run\n\t/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:196\ngh.neting.cc/elastic/beats/metricbeat/mb/module.(*Wrapper).Start.func1\n\t/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:137"}
2018-07-30T08:32:47.486Z	DEBUG	[publish]	pipeline/processor.go:308	Publish event: {
  "@timestamp": "2018-07-30T08:32:47.477Z",
  "@metadata": {
    "beat": "metricbeat",
    "type": "doc",
    "version": "6.5.0"
  },
  "metricset": {
    "name": "dommemstat",
    "module": "kvm",
    "host": "localhost",
    "rtt": 1355
  },
  "error": {
    "message": "dial: unknown network "
  },
  "beat": {
    "name": "ubuntu-bionic",
    "hostname": "ubuntu-bionic",
    "version": "6.5.0"
  },
  "host": {
    "name": "ubuntu-bionic"
  }
}

Stacktrace:

thub.com/elastic/beats/libbeat/logp.Recover
	/home/vagrant/go/src/github.com/elastic/beats/libbeat/logp/global.go:105
runtime.call32
	/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/asm_amd64.s:573
runtime.gopanic
	/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/panic.go:502
runtime.panicmem
	/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/panic.go:63
runtime.sigpanic
	/home/vagrant/.gvm/versions/go1.10.3.linux.amd64/src/runtime/signal_unix.go:388
github.com/elastic/beats/metricbeat/module/kvm/dommemstat.(*MetricSet).Fetch
	/home/vagrant/go/src/github.com/elastic/beats/metricbeat/module/kvm/dommemstat/dommemstat.go:108
github.com/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).fetch
	/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:238
github.com/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).startPeriodicFetching
	/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:209
github.com/elastic/beats/metricbeat/mb/module.(*metricSetWrapper).run
	/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:196
github.com/elastic/beats/metricbeat/mb/module.(*Wrapper).Start.func1
	/home/vagrant/go/src/github.com/elastic/beats/metricbeat/mb/module/wrapper.go:137