Node Configuration
The Node Configuration DB
As mentioned in the Warewulf Configuration
section, node configs are persisted to the nodes.conf YAML file,
but generally it is best not to edit this file directly (however that
is supported, it is just prone to errors).
This method of using a YAML configuration file as a backend datastore is both scalable and very lightweight. We’ve tested this out to over 10,000 node entries which yielded update latencies under 1 second, which we felt was both tolerable and advantageous.
Adding a New Node
Creating a new node is as simple as running the following command:
# wwctl node add n001 -I 172.16.1.11
Added node: n001
Adding several nodes
Several nodes can be added with a single command if a node range is given. An additional IP address will incremented. So the command
# wwctl node add n00[2-4] -I 172.16.1.12
Added node: n002
Added node: n003
Added node: n004
# wwctl node list -n n00[1-4]
NODE NAME NAME HWADDR IPADDR GATEWAY DEVICE
==========================================================================================
n001 default -- 172.16.1.11 -- (eth0)
n002 default -- 172.16.1.12 -- (eth0)
n003 default -- 172.16.1.13 -- (eth0)
n004 default -- 172.16.1.14 -- (eth0)
has added 4 nodes with the incremented IP addresses.
Node Names
For small clusters, you can use simple names (e.g. n0000); but for
larger, more complicated clusters that are comprised of multiple
clusters and roles it is highly recommended to use node names that
include a cluster descriptor. In Warewulf, this is generally done by
using a domain name (e.g. n001.cluster01). Warewulf will
automatically assume that the domain is the equivalent of the cluster
name.
This also means that you can address groups of nodes by the cluster
descriptor with globs. For example, you are able to refer to all nodes
in “cluster01” with the following string: *.cluster01 which is
valuable for other wwctl commands.
Listing Nodes
Once you have configured one or more nodes, you can list them and their attributes as follows:
# wwctl node list
NODE NAME PROFILES NETWORK
================================================================================
n001 default
You can also see the node’s full attribute list by specifying the
-a option (all):
# wwctl node list -a n001
NODE FIELD PROFILE VALUE
=====================================================================================
n001 Id -- n001
n001 comment default This profile is automatically included for each node
n001 cluster -- --
n001 container default sle-micro-5.3
n001 ipxe -- (default)
n001 runtime -- (generic)
n001 wwinit -- (wwinit)
n001 root -- (initramfs)
n001 discoverable -- --
n001 init -- (/sbin/init)
n001 asset -- --
n001 kerneloverride -- --
n001 kernelargs -- (quiet crashkernel=no vga=791 net.naming-scheme=v238)
n001 ipmiaddr -- --
n001 ipminetmask -- --
n001 ipmiport -- --
n001 ipmigateway -- --
n001 ipmiuser -- --
n001 ipmipass -- --
n001 ipmiinterface -- --
n001 ipmiwrite -- --
n001 profile -- default
n001 default:type -- (ethernet)
n001 default:onboot -- --
n001 default:netdev -- (eth0)
n001 default:hwaddr -- --
n001 default:ipaddr -- 172.16.1.11
n001 default:ipaddr6 -- --
n001 default:netmask -- (255.255.255.0)
n001 default:gateway -- --
n001 default:mtu -- --
n001 default:primary -- true
Note
The attribute values in parenthesis are default values and can be overridden in the next section, granted, the default values are generally usable.
Setting Node Attributes
In the above output we can see that there is no kernel or container defined for this node. To provision a node, the minimum requirements are a kernel and container, and for that node to be useful, we will also need to configure the network so the nodes are reachable after they boot.
Node configurations are set using the wwctl node set command. To
see a list of all configuration attributes, use the command wwctl
node set --help.
Configuring the Node’s Container Image
# wwctl node set --container rocky-8 n001
Are you sure you want to modify 1 nodes(s): y
And you can check that the container name is set for n001:
# wwctl node list -a n001 | grep Container
n0000 Container -- rocky-8
Configuring the Node’s Kernel
While the recommended method for assigning a kernel in 4.3 and beyond is to include it in the container / node image, a kernel can still be specified as an override at the node or profile. To illustrate this, we import the most recent kernel from a openSUSE Tumbleweed release.
# wwctl container import docker://registry.opensuse.org/science/warewulf/tumbleweed/containerfile/kernel:latest tw
# wwctl kernel import -DC tw
# wwctl kernel list
KERNEL NAME KERNEL VERSION NODES
tw 6.1.10-1-default 0
# wwctl node set --kerneloverride tw n001
Are you sure you want to modify 1 nodes(s): y
# wwctl node list -a n001 | grep kerneloverride
n001 kerneloverride -- tw
Configuring the Node’s Network
To configure the network, we have to pick a network device name and provide the network information as follows:
# wwctl node set --netdev eth0 --hwaddr 11:22:33:44:55:66 --ipaddr 10.0.2.1 --netmask 255.255.252.0 n001
Are you sure you want to modify 1 nodes(s): y
You can now see that the node contains configuration attributes for container, kernel, and network:
# wwctl node list -a n001
=====================================================================================
n001 Id -- n001
n001 comment default This profile is automatically included for each node
n001 cluster -- --
n001 container default sle-micro-5.3
n001 ipxe -- (default)
n001 runtime -- (generic)
n001 wwinit -- (wwinit)
n001 root -- (initramfs)
n001 discoverable -- --
n001 init -- (/sbin/init)
n001 asset -- --
n001 kerneloverride -- tw
n001 kernelargs -- (quiet crashkernel=no vga=791 net.naming-scheme=v238)
n001 ipmiaddr -- --
n001 ipminetmask -- --
n001 ipmiport -- --
n001 ipmigateway -- --
n001 ipmiuser -- --
n001 ipmipass -- --
n001 ipmiinterface -- --
n001 ipmiwrite -- --
n001 profile -- default
n001 default:type -- (ethernet)
n001 default:onboot -- --
n001 default:netdev -- eth0
n001 default:hwaddr -- 11:22:33:44:55:66
n001 default:ipaddr -- 10.0.2.1
n001 default:ipaddr6 -- --
n001 default:netmask -- 255.255.252.0
n001 default:gateway -- --
n001 default:mtu -- --
n001 default:primary -- true
# wwctl node set --cluster cluster01 n001
Are you sure you want to modify 1 nodes(s): y
# wwctl node list -a n001 | grep cluster
n001 cluster -- cluster01
Node Discovery
The hwaddr of a node can be automatically discovered by setting –discoverable on a node. If a node attempts to provision against Warewulf using an interface that is unknown to Warewulf, that address is associated with the first discoverable node. (Multiple discoverable nodes are sorted lexically, first by cluster, then by ID.)
Once a node has been discovered its “discoverable” flag is automatically cleared.
Un-setting Node Attributes
If you wish to unset a particular value, set the value to
UNDEF. For example:
And to unset this configuration attribute:
# wwctl node set --cluster UNDEF n001
Are you sure you want to modify 1 nodes(s): y
# wwctl node list -a n001 | grep Cluster
n001 Cluster -- --