netdata/netdata

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

package pgbouncer

import (
    "database/sql"
    _ "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/blang/semver/v4"
    _ "github.com/jackc/pgx/v4/stdlib"
)

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

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

func New() *PgBouncer {
    return &PgBouncer{
        Config: Config{
            Timeout: web.Duration(time.Second),
            DSN:     "postgres://postgres:postgres@127.0.0.1:6432/pgbouncer",
        },
        charts:               globalCharts.Copy(),
        recheckSettingsEvery: time.Minute * 5,
        metrics: &metrics{
            dbs: make(map[string]*dbMetrics),
        },
    }
}

type Config struct {
    UpdateEvery int          `yaml:"update_every,omitempty" json:"update_every"`
    DSN         string       `yaml:"dsn" json:"dsn"`
    Timeout     web.Duration `yaml:"timeout,omitempty" json:"timeout"`
}

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

    charts *module.Charts

    db *sql.DB

    version              *semver.Version
    recheckSettingsTime  time.Time
    recheckSettingsEvery time.Duration
    maxClientConn        int64

    metrics *metrics
}

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

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

    return nil
}

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

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

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

func (p *PgBouncer) Cleanup() {
    if p.db == nil {
        return
    }
    if err := p.db.Close(); err != nil {
        p.Warningf("cleanup: error on closing the PgBouncer database [%s]: %v", p.DSN, err)
    }
    p.db = nil
}