Hi, I wanted to understand how dos cloud-init, curtin and the ephemeral image work together.
I’m trying to write the role of each in the MAAS architecture.
Cloud-init has two configuration sources:
Cloud provider-supplied metadata: this stage happens before the image installation. Is this where curtin goes? it’s the configuration defined in curtin that goes in this stage?
User-supply configuration runs after the machine has Deployed. Here it’s the files that the user can run when they deploy a machine correct?
Ephemeral images, use cloud-init to discover the node’s hardware (e.g., number of CPUs,RAM, disk, etc.) and send that information to the MAAS Region controller.
So ephemeral images also use cloud-init.
Curtin
Curtin applies customization during operating system (OS) image installation. System parameterssuch as the type of kernel, disk partitioning, network configuration, swap memory configura-tion, among others, can be preconfigured in a preseed file that will automatically configureimages during the installation process
What I wanted to understand is the chronology of these events, what calls what and when. And what are the differences between them.
@jbacelo, just noticed this one. do you still need the answer? don’t know off the top of my heat, but i can probably play with MAAS and figure it out – if you still need to know.
If this information is even loosely documented somewhere (or a set of somewheres here and elsewhere) I’d like to read it. Can you recommend any links? What little we’ve achieved with Curtin configuratio, for example, has been from patchy material we have found over the years, plus a bit of trial and error.
I’d also like some more info on this if anyone comes across it. I’m attempting to fully manage a raspberry pi cluster from MaaS. Following some pcaps I did while MaaS was commissioning an a generic amd64 server, I was able to create a dhcp snippet that allows MaaS to PXE boot and mount the squashfs image provided by MaaS but I’m unable to get MaaS to commission the machine and I suspect it has to do with the initial scripts passed by curtain.
