Sometimes you have to deal with servers that you don’t know anything about:
- You are a short temp IT consultant with not previous knowledge on the environment.
- The CMDB is out of order.
- You are on a DR situation.
- Or simply the main administrator is not there.
And you need:
- Run commands in parallel
- Get info from many servers at a time
- Troubleshoot DNS problems
- Check how many servers are up and running
On my systems I use two orchestrators: MCollective and SaltStack (configured automatically using puppet) that fulfill my needs. But let’s see a quick way to have an orchestrator in a rapid manner.
Several months ago I finally got the (WOL) Wake On Lan feature of my RTL8111/8168B NIC card working. The problem was that a new driver (other than the provided by Debian) and a special PCI configuration was needed.
The other problem I had to deal with was the ADSL Router (Comtrend HG532c, The one provided by the Spanish ISP Jazztel) configuration:
- Open the required port: This was an easy one just opening the 7 a 9 port and forwarding them to the server we want to WOL from the internet
- Make the router remember the server’s tuple MAC/IP address. That was easy too, but some manual work was needed as when router is restarted the ARP table is flushed.
In my current job I had to change recently some configuration and restart more than 600 IP phones. To perform such titanic task I created a quick and dirty script using expect. It worked like a charm and made me think about automatize the way I set the ARP table in my Comtrend HG532c ADSL router.