netdata/netdata

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

package dnsmasq

import (
    _ "embed"
    "errors"
    "time"

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

    "github.com/miekg/dns"
)

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

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

func New() *Dnsmasq {
    return &Dnsmasq{
        Config: Config{
            Protocol: "udp",
            Address:  "127.0.0.1:53",
            Timeout:  web.Duration(time.Second),
        },

        newDNSClient: func(network string, timeout time.Duration) dnsClient {
            return &dns.Client{
                Net:     network,
                Timeout: timeout,
            }
        },
    }
}

type Config struct {
    UpdateEvery int          `yaml:"update_every,omitempty" json:"update_every"`
    Address     string       `yaml:"address" json:"address"`
    Protocol    string       `yaml:"protocol,omitempty" json:"protocol"`
    Timeout     web.Duration `yaml:"timeout,omitempty" json:"timeout"`
}

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

        charts *module.Charts

        dnsClient    dnsClient
        newDNSClient func(network string, timeout time.Duration) dnsClient
    }
    dnsClient interface {
        Exchange(msg *dns.Msg, address string) (resp *dns.Msg, rtt time.Duration, err error)
    }
)

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

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

    client, err := d.initDNSClient()
    if err != nil {
        d.Errorf("init DNS client: %v", err)
        return err
    }
    d.dnsClient = client

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

    return nil
}

func (d *Dnsmasq) Check() error {
    mx, err := d.collect()
    if err != nil {
        d.Error(err)
        return err
    }
    if len(mx) == 0 {
        return errors.New("no metrics collected")

    }
    return nil
}

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

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

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

func (d *Dnsmasq) Cleanup() {}