Merging local and ISO-contained NoCloud datasources

[dleidert]

I have a situation where an Ubuntu system must be deployed while it is not yet fully functional. There are some steps required to finish it, like installing some software. However, the user should be able to customize it as well, e.g. setting proxies, which are required to install the missing packages. Now, I have added a local config that reads:

datasource_list: [ NoCloud, None ]

datasource:
  NoCloud:
    seedfrom: file:///boot/mycloudinit

That directory contains a meta-data file with the instance-id, an empty user-data, and a vendor-data that contains the steps to finish the installation. The empty user-data file is required, or cloud-init will report an error. That works so far. Now, I add an ISO with a user-data (with some customizations) and a meta-data (with a different instance-id) file and created with cloud-localds. When I boot the system with the ISO attached, cloud-init sees it and reads it. It also uses the instance ID defined in the ISO's meta-data file. But it uses the empty user-data and the vendor-data from /boot/mycloudinit. I'm sorry, but I don't get that behavior. Why isn't it using the user-data from the ISO that has a valid syntax and is found first? Why isn't it using both? Shouldn't these, coming from the same type of datasource (NoCloud), be merged? I have been going through the documentation and running different scenarios for quite some time now, and I am not getting anywhere.

[holmanb]

Why not include the whole config in your disk?

Also, seedfrom config shouldn't be required if you are creating the disk with cloud-localds.