Actions before installing a new file

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1

I am looking for suggestions for the cleanest way to implement the following.

  • Have a template for /etc/network/interfaces

  • If it is different to the current version, then:

  • before the new version is installed, run “service networking stop”

  • install the new version

  • run “service networking start”

I am considering installing /etc/network/interfaces.ansible, and then having a handler something like

shell: if [ ! cmp /etc/network/interfaces /etc/network/interfaces.ansible ]; then service networking stop; cp /etc/networking/interfaces.ansible /etc/networking/interfaces; service networking start; fi

Is there a better way?

Thanks,

Brian.

2

I’m not sure you would want to disable networking in the middle of an Ansible run, also it is fine to replace a networking config file and then restart the service.

What you could do is just template the file and then have a handler be used to restart it on change, but just for that interface.

3

@micheal, if there are virtual interface changes, restarting with new config might leave the system in a bad state (won’t down interfaces you removed). I suppose this is why he wants to stop with old file and start with new.

@brian, I see no ‘better’ way of doing this as most ansible actions would need the networking which you just stopped.

4

You won’t be able to stop/start as you won’t be able to talk after you have stopped.

You can of course use the ‘script’ module to push something do all three (stop, cp, start)

5

I’m not sure you would want to disable networking in the middle of an Ansible run, also it is fine to replace a networking config file and then restart the service.

Unfortunately that doesn’t work with Debian/Ubuntu systems. ‘stop’ or ‘restart’ only downs the things which are currently listed in /etc/network/interfaces.

What you could do is just template the file and then have a handler be used to restart it on change, but just for that interface.

This is something a bit more general: it’s reconfiguring the server’s interfaces (as a VM platform). It will be adding new bridges and interfaces, and may be removing old bridges and interfaces.

It’s running with ansible_connection=local so I’m not too worried about downing the interfaces briefly.

But thanks, it looks like a script which does stop/cp/start is what’s needed.

Regards,

Brian.