netdata/netdata

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

package prometheus

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

    "github.com/netdata/netdata/go/go.d.plugin/agent/module"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/matcher"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/prometheus"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/prometheus/selector"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/web"
)

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

func init() {
    module.Register("prometheus", module.Creator{
        JobConfigSchema: configSchema,
        Defaults: module.Defaults{
            UpdateEvery: 10,
        },
        Create: func() module.Module { return New() },
    })
}

func New() *Prometheus {
    return &Prometheus{
        Config: Config{
            HTTP: web.HTTP{
                Client: web.Client{
                    Timeout: web.Duration(time.Second * 10),
                },
            },
            MaxTS:          2000,
            MaxTSPerMetric: 200,
        },
        charts: &module.Charts{},
        cache:  newCache(),
    }
}

type Config struct {
    web.HTTP        `yaml:",inline" json:""`
    UpdateEvery     int           `yaml:"update_every" json:"update_every"`
    Name            string        `yaml:"name" json:"name"`
    Application     string        `yaml:"app" json:"app"`
    BearerTokenFile string        `yaml:"bearer_token_file" json:"bearer_token_file"`
    Selector        selector.Expr `yaml:"selector" json:"selector"`
    ExpectedPrefix  string        `yaml:"expected_prefix" json:"expected_prefix"`
    MaxTS           int           `yaml:"max_time_series" json:"max_time_series"`
    MaxTSPerMetric  int           `yaml:"max_time_series_per_metric" json:"max_time_series_per_metric"`
    FallbackType    struct {
        Gauge   []string `yaml:"gauge" json:"gauge"`
        Counter []string `yaml:"counter" json:"counter"`
    } `yaml:"fallback_type" json:"fallback_type"`
}

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

    charts *module.Charts

    prom prometheus.Prometheus

    cache        *cache
    fallbackType struct {
        counter matcher.Matcher
        gauge   matcher.Matcher
    }
}

func (p *Prometheus) Configuration() any {
    return p.Config
}

func (p *Prometheus) Init() error {
    if err := p.validateConfig(); err != nil {
        p.Errorf("validating config: %v", err)
        return err
    }

    prom, err := p.initPrometheusClient()
    if err != nil {
        p.Errorf("init prometheus client: %v", err)
        return err
    }
    p.prom = prom

    m, err := p.initFallbackTypeMatcher(p.FallbackType.Counter)
    if err != nil {
        p.Errorf("init counter fallback type matcher: %v", err)
        return err
    }
    p.fallbackType.counter = m

    m, err = p.initFallbackTypeMatcher(p.FallbackType.Gauge)
    if err != nil {
        p.Errorf("init counter fallback type matcher: %v", err)
        return err
    }
    p.fallbackType.gauge = m

    return nil
}

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

func (p *Prometheus) Charts() *module.Charts {
    return p.charts
}

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

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

func (p *Prometheus) Cleanup() {
    if p.prom != nil && p.prom.HTTPClient() != nil {
        p.prom.HTTPClient().CloseIdleConnections()
    }
}