firehol/netdata

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

//go:build linux
// +build linux

package systemdunits

import (
    "context"
    "fmt"
    "strings"
    "time"

    "github.com/coreos/go-systemd/v22/dbus"
)

// https://github.com/systemd/systemd/blob/3d320785c4bbba74459096b07e85a79c4f0cdffb/src/shared/install.c#L3785
// see "is-enabled" in https://www.man7.org/linux/man-pages/man1/systemctl.1.html
var unitFileStates = []string{
    "enabled",
    "enabled-runtime",
    "linked",
    "linked-runtime",
    "alias",
    "masked",
    "masked-runtime",
    "static",
    "disabled",
    "indirect",
    "generated",
    "transient",
    "bad",
}

func (s *SystemdUnits) collectUnitFiles(mx map[string]int64, conn systemdConnection) error {
    if s.systemdVersion < 230 {
        return nil
    }

    if now := time.Now(); now.After(s.lastListUnitFilesTime.Add(s.CollectUnitFilesEvery.Duration())) {
        unitFiles, err := s.getUnitFilesByPatterns(conn)
        if err != nil {
            return err
        }
        s.lastListUnitFilesTime = now
        s.cachedUnitFiles = unitFiles
    }

    seen := make(map[string]bool)

    for _, unitFile := range s.cachedUnitFiles {
        seen[unitFile.Path] = true

        if !s.seenUnitFiles[unitFile.Path] {
            s.seenUnitFiles[unitFile.Path] = true
            s.addUnitFileCharts(unitFile.Path)
        }

        px := fmt.Sprintf("unit_file_%s_state_", unitFile.Path)
        for _, st := range unitFileStates {
            mx[px+st] = 0
        }
        mx[px+strings.ToLower(unitFile.Type)] = 1
    }

    for k := range s.seenUnitFiles {
        if !seen[k] {
            delete(s.seenUnitFiles, k)
            s.removeUnitFileCharts(k)
        }
    }

    return nil
}

func (s *SystemdUnits) getUnitFilesByPatterns(conn systemdConnection) ([]dbus.UnitFile, error) {
    ctx, cancel := context.WithTimeout(context.Background(), s.Timeout.Duration())
    defer cancel()

    s.Debugf("calling function 'ListUnitFilesByPatterns'")

    unitFiles, err := conn.ListUnitFilesByPatternsContext(ctx, nil, s.IncludeUnitFiles)
    if err != nil {
        return nil, fmt.Errorf("error on ListUnitFilesByPatterns: %v", err)
    }

    for i := range unitFiles {
        unitFiles[i].Path = cleanUnitName(unitFiles[i].Path)
    }

    s.Debugf("got %d unit files", len(unitFiles))

    return unitFiles, nil
}