netdata/netdata

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

package vnodes

import (
    "io"
    "io/fs"
    "log/slog"
    "os"
    "path/filepath"

    "github.com/netdata/netdata/go/go.d.plugin/logger"

    "gopkg.in/yaml.v2"
)

var Disabled = false // TODO: remove after Netdata v1.39.0. Fix for "from source" stable-channel installations.

func New(confDir string) *Vnodes {
    vn := &Vnodes{
        Logger: logger.New().With(
            slog.String("component", "vnodes"),
        ),

        confDir: confDir,
        vnodes:  make(map[string]*VirtualNode),
    }

    vn.readConfDir()

    return vn
}

type (
    Vnodes struct {
        *logger.Logger

        confDir string
        vnodes  map[string]*VirtualNode
    }
    VirtualNode struct {
        GUID     string            `yaml:"guid"`
        Hostname string            `yaml:"hostname"`
        Labels   map[string]string `yaml:"labels"`
    }
)

func (vn *Vnodes) Lookup(key string) (*VirtualNode, bool) {
    v, ok := vn.vnodes[key]
    return v, ok
}

func (vn *Vnodes) Len() int {
    return len(vn.vnodes)
}

func (vn *Vnodes) readConfDir() {
    _ = filepath.WalkDir(vn.confDir, func(path string, d fs.DirEntry, err error) error {
        if err != nil {
            vn.Warning(err)
            return nil
        }

        if !d.Type().IsRegular() || !isConfigFile(path) {
            return nil
        }

        var cfg []VirtualNode
        if err := loadConfigFile(&cfg, path); err != nil {
            vn.Warning(err)
            return nil
        }

        for _, v := range cfg {
            if v.Hostname == "" || v.GUID == "" {
                vn.Warningf("skipping virtual node '%+v': some required fields are missing (%s)", v, path)
                continue
            }
            if _, ok := vn.vnodes[v.Hostname]; ok {
                vn.Warningf("skipping virtual node '%+v': duplicate node (%s)", v, path)
                continue
            }

            v := v
            vn.Debugf("adding virtual node'%+v' (%s)", v, path)
            vn.vnodes[v.Hostname] = &v
        }

        return nil
    })
}

func isConfigFile(path string) bool {
    switch filepath.Ext(path) {
    case ".yaml", ".yml", ".conf":
        return true
    default:
        return false
    }
}

func loadConfigFile(conf interface{}, path string) error {
    f, err := os.Open(path)
    if err != nil {
        return err
    }
    defer func() { _ = f.Close() }()

    if err := yaml.NewDecoder(f).Decode(conf); err != nil && err != io.EOF {
        return err
    }

    return nil
}