Once a node has been commissioned the next logical step is to deploy it.
Deploying a node means, effectively, to install an operating system on it. The deployed node will also be ready to accept connections via SSH to the default user account 'ubuntu' if SSH keys have been imported to MAAS.
To deploy, the underlying machine needs to be configured to netboot (this should already have been done during the commissioning stage). Such a machine will undergo the following process:
- DHCP server is contacted
- kernel and initrd are received over TFTP
- machine boots
- initrd mounts a Squashfs image ephemerally over iSCSI
- cloud-init triggers deployment process
- curtin installation script is run
- Squashfs image (same as above) is placed on disk
Note: The curtin installer uses an image-based method and is now the only
installer used by MAAS. The older debian-installer (preseed) method has been
removed. Some remnants of preseed may still be found however. See
The agent that triggers deployment varies depending on how the nodes are intended to be used in the long term. For instance, if the nodes are destined to be running complex, inter-related services that may involve scaling up or down, that is, if they will be regarded as a "cloud" resource, then Juju is the recommended deploy agent (it will also install & configure services on the deployed nodes). If you simply want to use MAAS to install a base operating system and work on the machines manually then you can deploy a node directly with the web UI.
Before deploying you should:
- review and possibly set the kernel boot options and HWE kernels that may get used by deployed nodes.
- ensure any pertinent SSH keys are imported to MAAS so connections can be made to the deployed node.
To deploy directly from MAAS simply select any given node and press the 'Deploy' button.
You then have the option of deviating from the default OS, release, and kernel. When ready, press 'Go'.
While a node is deploying its status will change to Deploying.
Once a node has finished deploying its status will change to Deployed. The node now has an operating system installed and will accept SSH public key authentication requests to the 'ubuntu' account.