在bash中捕获来自"docker stop"的信号

Question

我在docker容器中有一个入口点脚本,如下所示:

#!/bin/bash

echo starting up

function shut_down() {
    echo shutting down

    pid=$(ps -e | grep myapp | awk '{print $1}')
    kill -SIGTERM $pid  
    exit
}

trap "shut_down" SIGKILL SIGTERM SIGHUP SIGINT EXIT

/opt/myapp

我无法弄清楚如何通过docker stop在容器上运行来捕获发送的信号.以交互方式运行时,a ctrl+c将按预期触发它,但docker stop命令只等待10秒超时,并在不进入shut_down函数的情况下退出

如何捕获docker stopbash 发送的信号进行一些清理？

Answer 1

老问题,但这将做的伎俩:

#!/bin/bash

echo starting up

exec /opt/myapp

详情请看:http://www.techbar.me/stopping-docker-containers-gracefully/

Answer 2

看看这个,可能会鼓舞人心:-)

更新:

@ nick-humrich这里是我的lamer副本和过去(功劳归原作者https://github.com/lgierth)

#!/bin/bash

function ensure_started_container {
  exists=`docker ps -q | grep $1`
  if [ "$?" = "0" ] ; then
    echo "[docker-exec] skipping docker start, already started"
  else
    output=`docker start "$1"`
    echo "[docker start] $output"
  fi
  running=1
}

function setup_signals {
  cid="$1"; shift
  handler="$1"; shift
  for sig; do
    trap "$handler '$cid' '$sig'" "$sig"
  done
}

function handle_signal {
  echo "[docker-exec] received $2"
  case "$2" in
    SIGINT)
      output=`docker stop -t 5 "$1"`
      echo "[docker stop] $output"
      running=0
      ;;
    SIGTERM)
      output=`docker stop -t 5 "$1"`
      echo "[docker stop] $output"
      running=0
      ;;
    SIGHUP)
      output=`docker restart -t 5 "$1"`
      echo "[docker restart] $output"

      # restart logging
      docker attach "$1" &
      kill "$logger_pid" 2> /dev/null
      logger_pid="$!"
      ;;
  esac
}

running=0

setup_signals "$1" "handle_signal" SIGINT SIGTERM SIGHUP

ensure_started_container "$1"

docker attach "$1" &
logger_pid="$!"

while true; do
  if [ "$running" = "1" ]; then
    sleep 1
  else
    break
  fi
done

exit_code=`docker wait "$1"`
exit "$exit_code"

Answer 3

从 Docker 1.9 开始，您可以使用STOPSIGNAL以下指令Dockerfile：

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\n

STOPSIGNAL signal\n

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设置STOPSIGNAL将发送到容器以退出的系统调用信号。该信号可以是与 kernel\xe2\x80\x99s 系统调用表中的位置匹配的有效无符号数字（例如 9），也可以是 SIGNAME 格式的信号名称（例如 SIGKILL）。

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来源： https: //docs.docker.com/engine/reference/builder/#stopsignal

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