firehol/netdata

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

package hdfs

import (
    _ "embed"
    "errors"
    "fmt"
    "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("hdfs", module.Creator{
        JobConfigSchema: configSchema,
        Create:          func() module.Module { return New() },
        Config:          func() any { return &Config{} },
    })
}

func New() *HDFS {
    config := Config{
        HTTPConfig: web.HTTPConfig{
            RequestConfig: web.RequestConfig{
                URL: "http://127.0.0.1:9870/jmx",
            },
            ClientConfig: web.ClientConfig{
                Timeout: confopt.Duration(time.Second),
            },
        },
    }

    return &HDFS{
        Config: config,
    }
}

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

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

        httpClient *http.Client

        nodeType
    }
    nodeType string
)

const (
    dataNodeType nodeType = "DataNode"
    nameNodeType nodeType = "NameNode"
)

func (h *HDFS) Configuration() any {
    return h.Config
}

func (h *HDFS) Init() error {
    if h.URL == "" {
        return errors.New("URL is required but not set")
    }

    httpClient, err := web.NewHTTPClient(h.ClientConfig)
    if err != nil {
        return fmt.Errorf("failed to create HTTP client: %v", err)
    }
    h.httpClient = httpClient

    return nil
}

func (h *HDFS) Check() error {
    typ, err := h.determineNodeType()
    if err != nil {
        return fmt.Errorf("error on node type determination : %v", err)
    }
    h.nodeType = typ

    mx, err := h.collect()
    if err != nil {
        return err
    }

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

    return nil
}

func (h *HDFS) Charts() *Charts {
    switch h.nodeType {
    default:
        return nil
    case nameNodeType:
        return nameNodeCharts()
    case dataNodeType:
        return dataNodeCharts()
    }
}

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

    return mx
}

func (h *HDFS) Cleanup() {
    if h.httpClient != nil {
        h.httpClient.CloseIdleConnections()
    }
}