firehol/netdata

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

package redis

import (
    "bufio"
    "context"
    "errors"
    "fmt"
    "regexp"
    "strings"

    "github.com/blang/semver/v4"
)

const precision = 1000 // float values multiplier and dimensions divisor

func (r *Redis) collect() (map[string]int64, error) {
    info, err := r.rdb.Info(context.Background(), "all").Result()
    if err != nil {
        return nil, err
    }

    if r.server == "" {
        s, v, err := extractServerVersion(info)
        if err != nil {
            return nil, fmt.Errorf("can not extract server app and version: %v", err)
        }
        r.server, r.version = s, v
        r.Debugf(`server="%s",version="%s"`, s, v)
    }

    if r.server != "redis" {
        return nil, fmt.Errorf("unsupported server app, want=redis, got=%s", r.server)
    }

    mx := make(map[string]int64)
    r.collectInfo(mx, info)
    r.collectPingLatency(mx)

    return mx, nil
}

// redis_version:6.0.9
var reVersion = regexp.MustCompile(`([a-z]+)_version:(\d+\.\d+\.\d+)`)

func extractServerVersion(info string) (string, *semver.Version, error) {
    var versionLine string
    for sc := bufio.NewScanner(strings.NewReader(info)); sc.Scan(); {
        line := sc.Text()
        if strings.Contains(line, "_version") {
            versionLine = strings.TrimSpace(line)
            break
        }
    }
    if versionLine == "" {
        return "", nil, errors.New("no version property")
    }

    match := reVersion.FindStringSubmatch(versionLine)
    if match == nil {
        return "", nil, fmt.Errorf("can not parse version property '%s'", versionLine)
    }

    server, version := match[1], match[2]
    ver, err := semver.New(version)
    if err != nil {
        return "", nil, err
    }

    return server, ver, nil
}