firehol/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package dnsquery

import (
    _ "embed"
    "time"

    "github.com/netdata/netdata/go/plugins/plugin/go.d/agent/module"
    "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/confopt"

    "github.com/miekg/dns"
)

//go:embed "config_schema.json"
var configSchema string

func init() {
    module.Register("dns_query", module.Creator{
        JobConfigSchema: configSchema,
        Defaults: module.Defaults{
            UpdateEvery: 5,
        },
        Create: func() module.Module { return New() },
        Config: func() any { return &Config{} },
    })
}

func New() *DNSQuery {
    return &DNSQuery{
        Config: Config{
            Timeout:     confopt.Duration(time.Second * 2),
            Network:     "udp",
            RecordTypes: []string{"A"},
            Port:        53,
        },
        newDNSClient: func(network string, timeout time.Duration) dnsClient {
            return &dns.Client{
                Net:         network,
                ReadTimeout: timeout,
            }
        },
    }
}

type Config struct {
    UpdateEvery int              `yaml:"update_every,omitempty" json:"update_every"`
    Timeout     confopt.Duration `yaml:"timeout,omitempty" json:"timeout"`
    Domains     []string         `yaml:"domains" json:"domains"`
    Servers     []string         `yaml:"servers" json:"servers"`
    Network     string           `yaml:"network,omitempty" json:"network"`
    RecordType  string           `yaml:"record_type,omitempty" json:"record_type"`
    RecordTypes []string         `yaml:"record_types,omitempty" json:"record_types"`
    Port        int              `yaml:"port,omitempty" json:"port"`
}

type (
    DNSQuery struct {
        module.Base
        Config `yaml:",inline" json:""`

        charts *module.Charts

        dnsClient    dnsClient
        newDNSClient func(network string, duration time.Duration) dnsClient

        recordTypes map[string]uint16
    }
    dnsClient interface {
        Exchange(msg *dns.Msg, address string) (response *dns.Msg, rtt time.Duration, err error)
    }
)

func (d *DNSQuery) Configuration() any {
    return d.Config
}

func (d *DNSQuery) Init() error {
    if err := d.verifyConfig(); err != nil {
        d.Errorf("config validation: %v", err)
        return err
    }

    rt, err := d.initRecordTypes()
    if err != nil {
        d.Errorf("init record type: %v", err)
        return err
    }
    d.recordTypes = rt

    charts, err := d.initCharts()
    if err != nil {
        d.Errorf("init charts: %v", err)
        return err
    }
    d.charts = charts

    return nil
}

func (d *DNSQuery) Check() error {
    return nil
}

func (d *DNSQuery) Charts() *module.Charts {
    return d.charts
}

func (d *DNSQuery) Collect() map[string]int64 {
    mx, err := d.collect()
    if err != nil {
        d.Error(err)
    }

    if len(mx) == 0 {
        return nil
    }
    return mx
}

func (d *DNSQuery) Cleanup() {}