firehol/netdata

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

package clickhouse

import (
    _ "embed"
    "errors"
    "net/http"
    "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/netdata/netdata/go/plugins/plugin/go.d/pkg/web"
)

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

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

func New() *ClickHouse {
    return &ClickHouse{
        Config: Config{
            HTTPConfig: web.HTTPConfig{
                RequestConfig: web.RequestConfig{
                    URL: "http://127.0.0.1:8123",
                },
                ClientConfig: web.ClientConfig{
                    Timeout: confopt.Duration(time.Second),
                },
            },
        },
        charts:       chCharts.Copy(),
        seenDisks:    make(map[string]*seenDisk),
        seenDbTables: make(map[string]*seenTable),
    }
}

type Config struct {
    UpdateEvery    int `yaml:"update_every,omitempty" json:"update_every"`
    web.HTTPConfig `yaml:",inline" json:""`
}

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

        charts *module.Charts

        httpClient *http.Client

        seenDisks    map[string]*seenDisk
        seenDbTables map[string]*seenTable
    }
    seenDisk  struct{ disk string }
    seenTable struct{ db, table string }
)

func (c *ClickHouse) Configuration() any {
    return c.Config
}

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

    httpClient, err := c.initHTTPClient()
    if err != nil {
        c.Errorf("init HTTP client: %v", err)
        return err
    }
    c.httpClient = httpClient

    c.Debugf("using URL %s", c.URL)
    c.Debugf("using timeout: %s", c.Timeout)

    return nil
}

func (c *ClickHouse) Check() error {
    mx, err := c.collect()
    if err != nil {
        c.Error(err)
        return err
    }

    if len(mx) == 0 {
        return errors.New("no metrics collected")
    }

    return nil
}

func (c *ClickHouse) Charts() *module.Charts {
    return c.charts
}

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

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

    return mx
}

func (c *ClickHouse) Cleanup() {
    if c.httpClient != nil {
        c.httpClient.CloseIdleConnections()
    }
}