netdata/netdata

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

package fail2ban

import (
    "context"
    "errors"
    "fmt"
    "os/exec"
    "strings"
    "time"

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

var errJailNotExist = errors.New("jail not exist")

func newFail2BanClientCliExec(ndsudoPath string, timeout time.Duration, log *logger.Logger) *fail2banClientCliExec {
    return &fail2banClientCliExec{
        Logger:     log,
        ndsudoPath: ndsudoPath,
        timeout:    timeout,
    }
}

type fail2banClientCliExec struct {
    *logger.Logger

    ndsudoPath string
    timeout    time.Duration
}

func (e *fail2banClientCliExec) status() ([]byte, error) {
    return e.execute("fail2ban-client-status")
}

func (e *fail2banClientCliExec) jailStatus(jail string) ([]byte, error) {
    return e.execute("fail2ban-client-status-jail", "--jail", jail)
}

func (e *fail2banClientCliExec) execute(args ...string) ([]byte, error) {
    ctx, cancel := context.WithTimeout(context.Background(), e.timeout)
    defer cancel()

    cmd := exec.CommandContext(ctx, e.ndsudoPath, args...)
    e.Debugf("executing '%s'", cmd)

    bs, err := cmd.Output()
    if err != nil {
        if strings.HasPrefix(strings.TrimSpace(string(bs)), "Sorry but the jail") {
            return nil, errJailNotExist
        }
        return nil, fmt.Errorf("error on '%s': %v", cmd, err)
    }

    return bs, nil
}