docker exec不在cron中工作

Question

我有一个非常简单的命令,它作为一个命令或bash脚本独立工作,但当我把它放在crontab中时

40 05 * * * bash /root/scripts/direct.sh >> /root/cron.log

有以下行

PATH=$PATH:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
SHELL=/bin/sh PATH=/bin:/sbin:/usr/bin:/usr/sbin:/root/
# Mongo Backup
docker exec -it mongodb mongodump -d meteor -o /dump/

我试图改变脚本的网址,/usr/bin/scirpts/没有运气

我甚至试图直接在cron中运行脚本

26 08 * * * docker exec -it mongodb mongodump -d meteor -o /dump/ >> /root/cron.log

没有运气,任何帮助表示赞赏.

编辑

我也没有在/root/cron.log文件中看到任何错误

Answer 1

您的docker exec命令说它需要"伪终端并以交互模式运行"(-it flags),而cron不会附加到任何TTY.

尝试将docker exec命令改为此命令,看看是否有效？

docker exec mongodb mongodump -d meteor -o /dump/

Answer 2

cron debugging

1. /var/log or sendmail

As crond work as a daemon, without ability of failing, execution is more important than logging. Then by default, if something goes wrong, cron will send a mail to $USER@localhost reporting script output and errors.

Have a look at /var/mail or /var/spool/mail for some mails, maybe

and at /etc/aliases to see where root's mail are sents.

2. crond and $PATH

When you run a command by cron, have care that $PATH is user's default path and not root default path (ie no */sbin and other reserved path to super user tools).

For this, the simplier way is to print your default path in the environment where everything run fine:

echo $PATH

or patch your script from command line:

sed -e "2aPATH='$PATH'" -i /root/scripts/direct.sh

This will add current $PATH initializer at line 2 in your script.

Or this, will whipe from your script all other PATH=:

sed -e "s/PATH=[^ ]*\( \|$\)/\1/;2aPATH='$PATH'" -i /root/scripts/direct.sh

3. Force logging

Add at top of your script:

exec 1>/tmp/cronlog-$$.log
exec 2>/tmp/cronlog-$$.err

Try this:

sed -e '1a\\nexec 1>/tmp/cronlog-$$.log\nexec 2>/tmp/cronlog-$$.err' -i ~/scripts/direct.sh

Finalized script could look like:

#!/bin/bash

# uncomment two following lines to force log to /tmp
# exec 1>/tmp/cronlog-$$.log
# exec 2>/tmp/cronlog-$$.err

PATH='....' # copied from terminal console!

docker exec -it mongodb mongodump -d meteor -o /dump/

Executable flag

If you run your script by

40 05 * * * bash /root/scripts/direct.sh

no executable flag are required, but you must add them:

chmod +x ~/scripts/direct.sh

if you want to run:

40 05 * * * /root/scripts/direct.sh

Answer 3

为了它的价值我有同样的问题.修复你的PATH,更改权限,并确保你作为适当的docker用户运行都是好事,但这还不够.它会继续失败,因为你正在使用"docker exec -it",它告诉docker使用交互式shell.将其更改为"docker exec -t",它将正常工作.但是,在任何地方都没有记录输出.请享用!

Answer 4

1) 确保此任务在root用户的 crontab 中 - 可能是这种情况，但您没有明确写入

2）cron可能无法找到bash。我会删除它并在使其可执行后直接调用您的脚本：

chmod 755 /root/scripts/direct.sh

然后将您的 crontab 条目设置为 40 05 * * * /root/scripts/direct.sh 2>&1 >> /root/cron.log

如果它仍然不起作用，那么你应该有一些有用的输出 /root/cron.log