5f1a42543c
Fixes https://github.com/containerd/containerd/issues/7941 Signed-off-by: Samuel Karp <samuelkarp@google.com>
113 lines
2.8 KiB
Go
113 lines
2.8 KiB
Go
//go:build !windows
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/*
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Copyright The containerd Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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package shim
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import (
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"context"
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"fmt"
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"io"
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"net"
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"os"
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"os/signal"
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"syscall"
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"github.com/containerd/containerd/sys/reaper"
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"github.com/containerd/fifo"
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"github.com/sirupsen/logrus"
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"golang.org/x/sys/unix"
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)
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// setupSignals creates a new signal handler for all signals and sets the shim as a
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// sub-reaper so that the container processes are reparented
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func setupSignals(config Config) (chan os.Signal, error) {
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signals := make(chan os.Signal, 32)
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smp := []os.Signal{unix.SIGTERM, unix.SIGINT, unix.SIGPIPE}
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if !config.NoReaper {
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smp = append(smp, unix.SIGCHLD)
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}
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signal.Notify(signals, smp...)
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return signals, nil
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}
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func setupDumpStacks(dump chan<- os.Signal) {
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signal.Notify(dump, syscall.SIGUSR1)
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}
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func serveListener(path string) (net.Listener, error) {
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var (
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l net.Listener
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err error
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)
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if path == "" {
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l, err = net.FileListener(os.NewFile(3, "socket"))
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path = "[inherited from parent]"
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} else {
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if len(path) > socketPathLimit {
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return nil, fmt.Errorf("%q: unix socket path too long (> %d)", path, socketPathLimit)
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}
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l, err = net.Listen("unix", path)
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}
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if err != nil {
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return nil, err
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}
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logrus.WithField("socket", path).Debug("serving api on socket")
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return l, nil
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}
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func reap(ctx context.Context, logger *logrus.Entry, signals chan os.Signal) error {
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logger.Debug("starting signal loop")
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for {
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select {
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case <-ctx.Done():
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return ctx.Err()
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case s := <-signals:
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// Exit signals are handled separately from this loop
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// They get registered with this channel so that we can ignore such signals for short-running actions (e.g. `delete`)
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switch s {
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case unix.SIGCHLD:
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if err := reaper.Reap(); err != nil {
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logger.WithError(err).Error("reap exit status")
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}
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case unix.SIGPIPE:
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}
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}
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}
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}
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func handleExitSignals(ctx context.Context, logger *logrus.Entry, cancel context.CancelFunc) {
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ch := make(chan os.Signal, 32)
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signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
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for {
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select {
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case s := <-ch:
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logger.WithField("signal", s).Debugf("Caught exit signal")
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cancel()
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return
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case <-ctx.Done():
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return
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}
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}
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}
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func openLog(ctx context.Context, _ string) (io.Writer, error) {
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return fifo.OpenFifoDup2(ctx, "log", unix.O_WRONLY, 0700, int(os.Stderr.Fd()))
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}
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