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art vanderlay
Asked: 2014-06-21 12:37:15 +0800 CST

ec2 upstart, what is the `start on` command to wait for network

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This is my first time with upstart and am using EC2.

os/upstart = aws base AMI latest version - upstart-0.6.5-13.3.13.amzn1.x86_64

I can not get the following script to launch when waiting for the network to initiate. It will work if using standard

 start on runlevel [2345]
 stop on runlevel [!2345]

I have also tried various combinations of

start on filesystem and net-device-up IFACE=eth0
start on filesystem and net-device-up IFACE!=lo

Any suggestions would be grateful

description "test for on network start"


start on (started network-interface
      or started network-manager
      or started networking)

stop on (stopping network-interface
     or stopping network-manager
     or stopping networking)


script
    touch /home/ec2-user/myFile.txt
end script
amazon-ec2

2 Answers

  1. Upstart is an event based system. For your job to execute at a correct stage it may need to wait for particular event(s) emitted by other start up job(s).

    Possible solutions will differ from system to system and will depend on how upstart jobs are defined and what events they emit. It may also depend on the upstart version installed on the system.

    Please note that upstart might not write it's logs to /var/log/upstart. Earlier versions may use syslogd while newer ones are more likely to write logs to /var/log/upstart.

    Below solution will only work on the type of the system mentioned in the question:

    os/upstart = aws base AMI latest version - upstart-0.6.5-13.3.13.amzn1.x86_64

    On this system upstart didn't log job echo statements anywhere. So this part may require extra configuration.

    Job definition:

    description "testjob"

start on started elastic-network-interfaces

script
        echo $(ping -c 1 serverfault.com) > /var/log/testjob.log
end script

    Test on a real EC2 instance:

    # cat /var/log/testjob.log 
PING serverfault.com (198.252.206.140) 56(84) bytes of data. 64 bytes from stackoverflow.com (198.252.206.140): icmp_seq=1 ttl=51 time=72.9 ms --- serverfault.com ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 73ms rtt min/avg/max/mdev = 72.950/72.950/72.950/0.000 ms
    • 2

  2. Your example is realllly close.

    Amazon Linux calls their networking service network. So if the application/service you're attempting to control with upstart requires a network connection, do this:

    start on (runlevel [345] and started network)
stop on (runlevel [!345] or stopping network)

    You don't need the runlevel bits, but its not a bad idea to be able to limit the service from running depending on the run level environment.

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