warewulf/docs/docs/quickstart/el7.md

id, title

id	title
el7	Quick Start for RHEL and CentOS 7

Install Warewulf and dependencies

sudo yum install epel-release
sudo yum install golang tftp-server dhcp nfs-utils

git clone https://github.com/hpcng/warewulf.git
cd warewulf
make all
sudo make install

Configure firewalld

Restart firewalld to register the added service file, add the service to the default zone, and reload.

sudo systemctl restart firewalld
sudo firewall-cmd --permanent --add-service warewulf
sudo firewall-cmd --reload

Configure the controller

Edit the file /etc/warewulf/warewulf.conf and ensure that you've set the appropriate configuration paramaters. Here are some of the defaults for reference:

ipaddr: 192.168.1.1
netmask: 255.255.255.0
warewulf:
  port: 9873
  secure: true
  update interval: 60
dhcp:
  enabled: true
  range start: 192.168.1.150
  range end: 192.168.1.200
  template: default
  systemd name: dhcpd
tftp:
  enabled: true
  tftproot: /var/lib/tftpboot
  systemd name: tftp
nfs:
  systemd name: nfs-server
  exports:
    - /home
    - /var/warewulf

Start and enable the Warewulf service

# Create the group the warewulfd service will run as
sudo groupadd -r warewulf

# Reload system services
sudo systemctl daemon-reload

# Start and enable the warewulfd service
sudo systemctl enable --now warewulfd

Configure system services automatically

sudo wwctl configure dhcp # Create the default dhcpd.conf file and start/enable service
sudo wwctl configure tftp # Install the base tftp/PXE boot files and start/enable service
sudo wwctl configure nfs  # Configure the exports and create an fstab in the default system overlay
sudo wwctl configure ssh  # Build the basic ssh keys to be included by the default system overlay
sudo systemctl start warewulfd

Pull and build the VNFS container and kernel

This will pull a basic VNFS container from Docker Hub and import the default running kernel from the controller node and set both in the "default" node profile.

sudo wwctl container import docker://warewulf/centos-7 centos-7 --setdefault
sudo wwctl kernel import $(uname -r) --setdefault

Set up the default node profile

The --setdefault arguments above will automatically set those entries in the default profile, but if you wanted to set them by hand to something different, you can do the following:

sudo wwctl profile set default -K $(uname -r) -C centos-7

Next we set some default networking configurations for the first ethernet device. On modern Linux distributions, the name of the device is not critical, as it will be setup according to the HW address. Because all nodes will share the netmask and gateway configuration, we can set them in the default profile as follows:

sudo wwctl profile set default --netdev eth0 -M 255.255.255.0 -G 192.168.1.1
sudo wwctl profile list

Add a node and build node specific overlays

Adding nodes can be done while setting configurations in one command. Here we are setting the IP address of eth0 and setting this node to be discoverable, which will then automatically have the HW address added to the configuration as the node boots.

Node names must be unique. If you have node groups and/or multiple clusters, designate them using dot notation.

Note that the full node configuration comes from both cascading profiles and node configurations which always supersede profile configurations.

sudo wwctl node add n0000.cluster --netdev eth0 -I 192.168.1.100 --discoverable
sudo wwctl node list -a n0000

Warewulf Overlays

There are two types of overlays: system and runtime overlays.

System overlays are provisioned to the node before /sbin/init is called. This enables us to prepopulate node configurations with content that is node specific like networking and service configurations.

Runtime overlays are provisioned after the node has booted and periodically during the normal runtime of the node. Because these overlays are provisioned at periodic intervals, they are very useful for content that changes, like users and groups.

Overlays are generated from a template structure that is viewed using the wwctl overlay commands. Files that end in the .ww suffix are templates and abide by standard text/template rules. This supports loops, arrays, variables, and functions making overlays extremely flexible.

:::note When using the overlay subsystem, system overlays are never shown by default. So when running overlay commands, you are always looking at runtime overlays unless the -s option is passed. :::

All overlays are compiled before being provisioned. This accelerates the provisioning process because there is less to do when nodes are being managed at scale.

Here are some of the common overlay commands:

sudo wwctl overlay list -l
sudo wwctl overlay list -ls
sudo wwctl overlay edit default /etc/hello_world.ww
sudo wwctl overlay build -a

Boot your compute node and watch it boot