User-data scripts is not running on my custom AMI, but working in standard Amazon linux

User_data is run only at the first start up. As your image is a custom one, I suppose it have already been started once and so user_data is desactivated.

For windows, it can be done by checking a box in Ec2 Services Properties. I'm looking at the moment how to do that in an automated way at the end of the custom image creation.

For linux, I suppose the mechanism is the same, and user_data needs to be re-activated on your custom image.

The #cloud-boothook make it works because it changes the script from a user_data mechanism to a cloud-boothook one that runs on each start.

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EDIT :

Here is the code to reactivate start on windows using powershell:

$configFile = "C:\\Program Files\\Amazon\\Ec2ConfigService\\Settings\\Config.xml"
[xml] $xdoc = get-content $configFile
$xdoc.SelectNodes("//Plugin") |?{ $_.Name -eq "Ec2HandleUserData"} |%{ $_.State = "Enabled" }
$xdoc.SelectNodes("//Plugin") |?{ $_.Name -eq "Ec2SetComputerName"} |%{ $_.State = "Enabled" }
$xdoc.OuterXml | Out-File -Encoding UTF8 $configFile

$configFile = "C:\\Program Files\\Amazon\\Ec2ConfigService\\Settings\\BundleConfig.xml"
[xml] $xdoc = get-content $configFile
$xdoc.SelectNodes("//Property") |?{ $_.Name -eq "AutoSysprep"} |%{ $_.Value = "Yes" }
$xdoc.OuterXml | Out-File -Encoding UTF8 $configFile

(I know the question focus linux, but it could help others ...)

As I tested, there were some bootstrap data in /var/lib/cloud directory. After I cleared that directory, User Data script worked normally.

rm -rf /var/lib/cloud/*

I have also faced the same issue on Ubuntu 16.04 hvm AMI. I have raised the issue to AWS support but still I couldn't find exact reason/bug which affects it.

But still I have something which might help you.

Before taking AMI remove /var/lib/cloud directory (each time). Then while creating Image, set it to no-reboot.

If these things still ain't working, you can test it further by forcing user-data to run manually. Also tailf /var/log/cloud-init-output.log for cloud-init status. It should end with something like modules:final to make your user-data run. It should not stuck on modules:config.

sudo rm -rf /var/lib/cloud/* sudo cloud-init init sudo cloud-init modules -m final

I don't have much idea whether above commands will work on CentOS or not. I have tested it on Ubuntu.

In my case, I have also tried removing /var/lib/cloud directory, but still it failed to execute user-data in our scenario. But I have came up with different solution for it. What we have did is we have created script with above commands and made that script to run while system boots.

I have added below line in /etc/rc.local to make it happen.

sudo bash /home/ubuntu/force-user-data.sh || exit 1

But here is the catch, it will execute the script on each boot so which will make your user-data to run on every single boot, just like #cloud-boothook. No worries, you can just tweak it by just removing the force-user-data.sh itself at the end. So your force-user-data.sh will look something like

#!/bin/bash sudo rm -rf /var/lib/cloud/* sudo cloud-init init sudo cloud-init modules -m final sudo rm -f /home/ubuntu/force-user-data.sh exit 0

I will appreciate if someone can put some lights on why it is unable to execute the user-data.