github.com/meulengracht/snapd@v0.0.0-20210719210640-8bde69bcc84e/overlord/configstate/configcore/watchdog.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2018 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package configcore
    21  
    22  import (
    23  	"fmt"
    24  	"os"
    25  	"sort"
    26  	"strings"
    27  	"time"
    28  
    29  	"github.com/snapcore/snapd/dirs"
    30  	"github.com/snapcore/snapd/osutil"
    31  	"github.com/snapcore/snapd/overlord/configstate/config"
    32  	"github.com/snapcore/snapd/sysconfig"
    33  	"github.com/snapcore/snapd/systemd"
    34  )
    35  
    36  func init() {
    37  	// add supported configuration of this module
    38  	supportedConfigurations["core.watchdog.runtime-timeout"] = true
    39  	supportedConfigurations["core.watchdog.shutdown-timeout"] = true
    40  }
    41  
    42  func updateWatchdogConfig(config map[string]uint, opts *fsOnlyContext) error {
    43  	var sysd systemd.Systemd
    44  
    45  	dir := dirs.SnapSystemdConfDir
    46  	if opts != nil {
    47  		dir = dirs.SnapSystemdConfDirUnder(opts.RootDir)
    48  	} else {
    49  		sysd = systemd.NewUnderRoot(dirs.GlobalRootDir, systemd.SystemMode, &sysdLogger{})
    50  	}
    51  
    52  	name := "10-snapd-watchdog.conf"
    53  	dirContent := make(map[string]osutil.FileState, 1)
    54  
    55  	configStr := []string{}
    56  	for k, v := range config {
    57  		if v > 0 {
    58  			configStr = append(configStr, fmt.Sprintf("%s=%d\n", k, v))
    59  		}
    60  	}
    61  	if len(configStr) > 0 {
    62  		if err := os.MkdirAll(dir, 0755); err != nil {
    63  			return err
    64  		}
    65  
    66  		// We order the variables to have predictable output
    67  		sort.Strings(configStr)
    68  		content := "[Manager]\n" + strings.Join(configStr, "")
    69  		dirContent[name] = &osutil.MemoryFileState{
    70  			Content: []byte(content),
    71  			Mode:    0644,
    72  		}
    73  	}
    74  
    75  	glob := name
    76  	changed, removed, err := osutil.EnsureDirState(dir, glob, dirContent)
    77  	if err != nil {
    78  		return err
    79  	}
    80  
    81  	// something was changed, reexec systemd manager
    82  	if sysd != nil && (len(changed) > 0 || len(removed) > 0) {
    83  		return sysd.DaemonReexec()
    84  	}
    85  
    86  	return nil
    87  }
    88  
    89  func handleWatchdogConfiguration(_ sysconfig.Device, tr config.ConfGetter, opts *fsOnlyContext) error {
    90  	config := map[string]uint{}
    91  
    92  	for _, key := range []string{"runtime-timeout", "shutdown-timeout"} {
    93  		output, err := coreCfg(tr, "watchdog."+key)
    94  		if err != nil {
    95  			return err
    96  		}
    97  		secs, err := getSystemdConfSeconds(output)
    98  		if err != nil {
    99  			return fmt.Errorf("cannot set timer to %q: %v", output, err)
   100  		}
   101  		switch key {
   102  		case "runtime-timeout":
   103  			config["RuntimeWatchdogSec"] = secs
   104  		case "shutdown-timeout":
   105  			config["ShutdownWatchdogSec"] = secs
   106  		}
   107  	}
   108  
   109  	if err := updateWatchdogConfig(config, opts); err != nil {
   110  		return err
   111  	}
   112  
   113  	return nil
   114  }
   115  
   116  func getSystemdConfSeconds(timeStr string) (uint, error) {
   117  	if timeStr == "" {
   118  		return 0, nil
   119  	}
   120  
   121  	dur, err := time.ParseDuration(timeStr)
   122  	if err != nil {
   123  		return 0, fmt.Errorf("cannot parse %q: %v", timeStr, err)
   124  	}
   125  	if dur < 0 {
   126  		return 0, fmt.Errorf("cannot use negative duration %q: %v", timeStr, err)
   127  	}
   128  
   129  	return uint(dur.Seconds()), nil
   130  }
   131  
   132  func validateWatchdogOptions(tr config.ConfGetter) error {
   133  	for _, key := range []string{"runtime-timeout", "shutdown-timeout"} {
   134  		option, err := coreCfg(tr, "watchdog."+key)
   135  		if err != nil {
   136  			return err
   137  		}
   138  		if _, err = getSystemdConfSeconds(option); err != nil {
   139  			return err
   140  		}
   141  	}
   142  
   143  	return nil
   144  }