Disabling cloud-init if metadata server cannot be reached

cloud-init

I'm trying to get cloud-init to not take any action if the metadata server cannot be reached. If cloud-init ignores the error and continues executing (which seems to be the default configuration), then it resets the host SSH key, administrative user password, etc., which is a problem if the virtual machine was being used already beforehand (if password login was configured, then users can no longer access the VM).

I'm seeing this problem in two situations:

The metadata server goes down
Software is installed that blocks connections to the metadata server during boot (most recently, seeing this with ubuntu-desktop)

Best Answer

Ah, I figured it out, the reason that it's continuing executing despite not successfully reaching any data sources is because the Fallback/None data source was configured in /etc/cloud/cloud.cfg.d/90_dpkg.cfg

I deleted this file and configured in /etc/cloud/cloud.cfg:

datasource_list: [ OpenStack, Ec2 ]

And then it no longer executes.

Related Solutions

Ubuntu – In Amazon EC2, what’s the best way to clone a private github repository on boot

Normally, I would recommend that you create a working EC2 instance with the SSH key and git repo clone (a working instance with your ideal configuration).

Then create a AMI of that instance and in the launch configuration enter your scripts in the userdata so that the scripts would run each time (basically update git and launch command) when the instance is launched.

Sample script would be (assuming /opt/src is where your repo is):

#!/bin/sh
cd /opt/src
git pull
source run_cmd.sh

This way your script is contained and well maintained. Hope that helps.

Docker – How to execute some commands before the user scripts in cloud-init

@smoser from the irc #cloud-init helped me

look in /var/lib/cloud/instance/scripts/ you'll see one file named runcmd and the other files that are in your multipart are named by their filename.

The scripts in that directory are run in C locale sorted order (as if by runparts)

So if you change the name of the script you've added from filename="00-rancher_server_install" to filename="zz-rancher_server_install" then yo'ull be good.

Best Answer

Related Solutions

Ubuntu – In Amazon EC2, what’s the best way to clone a private github repository on boot

Docker – How to execute some commands before the user scripts in cloud-init

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