74 lines
2.0 KiB
Go
74 lines
2.0 KiB
Go
// Copyright 2016 CoreOS, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package daemon
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import (
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"fmt"
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"os"
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"strconv"
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"time"
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)
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// SdWatchdogEnabled returns watchdog information for a service.
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// Processes should call daemon.SdNotify(false, daemon.SdNotifyWatchdog) every
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// time / 2.
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// If `unsetEnvironment` is true, the environment variables `WATCHDOG_USEC` and
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// `WATCHDOG_PID` will be unconditionally unset.
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//
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// It returns one of the following:
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// (0, nil) - watchdog isn't enabled or we aren't the watched PID.
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// (0, err) - an error happened (e.g. error converting time).
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// (time, nil) - watchdog is enabled and we can send ping. time is delay
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// before inactive service will be killed.
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func SdWatchdogEnabled(unsetEnvironment bool) (time.Duration, error) {
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wusec := os.Getenv("WATCHDOG_USEC")
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wpid := os.Getenv("WATCHDOG_PID")
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if unsetEnvironment {
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wusecErr := os.Unsetenv("WATCHDOG_USEC")
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wpidErr := os.Unsetenv("WATCHDOG_PID")
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if wusecErr != nil {
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return 0, wusecErr
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}
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if wpidErr != nil {
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return 0, wpidErr
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}
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}
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if wusec == "" {
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return 0, nil
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}
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s, err := strconv.Atoi(wusec)
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if err != nil {
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return 0, fmt.Errorf("error converting WATCHDOG_USEC: %s", err)
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}
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if s <= 0 {
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return 0, fmt.Errorf("error WATCHDOG_USEC must be a positive number")
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}
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interval := time.Duration(s) * time.Microsecond
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if wpid == "" {
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return interval, nil
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}
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p, err := strconv.Atoi(wpid)
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if err != nil {
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return 0, fmt.Errorf("error converting WATCHDOG_PID: %s", err)
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}
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if os.Getpid() != p {
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return 0, nil
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}
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return interval, nil
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}
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