从cron作业中的shell脚本启动服务（upstart） [英] Starting a service (upstart) from a shell script, from a cron job

问题描述

我想使用cron作业来调用我编写的healthcheck脚本来检查我编写的网络应用程序（api）的状态（一个url调用不足以测试完整的功能，因此自定义健康检查）。 healthcheck应用程序有几个端点，它们从shell脚本（见下文）调用，这个脚本重新启动我们正在检查的更大的web应用程序。自然，我有麻烦。

I'm trying to use a cron job to call a healthcheck script I've written to check the status of a web app (api) I've written (a url call doesn't suffice to test full functionality, hence the custom healthcheck). The healthcheck app has several endpoints which are called from a shell script (see below), and this script restarts the bigger web app we are checking. Naturally, I'm having trouble.

它如何工作：
1）cron作业每60秒运行
2）healthcheck脚本由cron job
3）healthcheck脚本检查url，如果url返回非200响应，则停止并启动服务

How it works: 1) cron job runs every 60s 2) healthcheck script is run by cron job 3) healthcheck script checks url, if url returns non-200 response, it stops and start a service

有什么作用：
1）我可以运行脚本（healthcheck.sh）作为ec2-user
2）我可以运行脚本作为root
3）cron作业调用脚本，它运行，但它不停止/启动服务（我可以通过观察/tmp/crontest.txt和ps aux看到这个）。

What works: 1) I can run the script (healthcheck.sh) as the ec2-user 2) I can run the script as root 3) The cron job calls the script and it runs, but it doesn't stop/start the service (I can see this by watching /tmp/crontest.txt and ps aux).

它看起来像一个权限问题或一些非常基本的linux东西

It totally seems like a permissions issue or some very basic linux thing that I'm not aware of.

当我以root或ec2-user身份运行时的日志（/ tmp / crontest .txt）：

The log when I run as root or ec2-user (/tmp/crontest.txt):

Fri Nov 23 00:28:54 UTC 2012
healthcheck.sh: api not running, restarting service!
api start/running, process 1939 <--- it restarts the service properly!

cron作业运行时的日志：

The log when the cron job runs:

Fri Nov 23 00:27:01 UTC 2012
healthcheck.sh: api not running, restarting service! <--- no restart

Cron文件（在/etc/cron.d):

Cron file (in /etc/cron.d):

# Call the healthcheck every 60s
* * * * * root /srv/checkout/healthcheck/healthcheck.sh >> /tmp/crontest.txt

Upstart脚本（/etc/init/healthcheck.conf）对于healthcheck应用程序，它提供了我们从shell脚本healthcheck.sh调用的端点：

Upstart script (/etc/init/healthcheck.conf)- this is for the healthcheck app, which provides endpoints which we call from the shell script healthcheck.sh:

#/etc/init/healthcheck.conf
description "healthcheck"
author "me"

env USER=ec2-user

start on started network
stop on stopping network

script
    # We run our process as a non-root user
    # Upstart user guide, 11.43.2 (http://upstart.ubuntu.com/cookbook/#run-a-job-as-a-different-user)
    exec su -s /bin/sh -c "NODE_ENV=production /usr/local/bin/node /srv/checkout/healthcheck/app.js" $USER
end script

Shell脚本权限：

Shell script permissions:

-rwxr-xr-x 1 ec2-user ec2-user 529 Nov 23 00:16 /srv/checkout/healthcheck/healthcheck.sh

Shell脚本（healthcheck.sh）：

Shell script (healthcheck.sh):

#!/bin/bash

API_URL="http://localhost:4567/api"

echo `date`

status_code=`curl -s -o /dev/null -I -w "%{http_code}" $API_URL`
if [ 200 -ne $status_code ]; then
  echo "healthcheck.sh: api not running, restarting service!"
  stop api
  start api
fi

推荐答案

为脚本添加开始/停止命令的路径：

Add path to start/stop command to your script:

#!/bin/bash

PATH=$PATH:/sbin/

命令：

/sbin/stop api

您可以使用whereis查看他们的路径：

you can check path to them using whereis:

$ whereis start
/sbin/start

这篇关于从cron作业中的shell脚本启动服务（upstart）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！