This project aims to create a PXE guest to install other servers (for now CentOS7 en CoreOS)

The PXE server will contain the following services:

• Named
• TFTP
• DHCP
• Nginx

Variables

export PXE_STAGE=/opt/stage/pxe
mkdir -p ${PXE_STAGE}
cd ${PXE_STAGE}
export CENTOS_ISO=CentOS-7-x86_64-DVD-1810.iso

Downloads

curl -s http://mirrors.up.pt/pub/centos/7.6.1810/isos/x86_64/CentOS-7-x86_64-DVD-1810.iso -O ${PXE_STAGE}/CentOS-7-x86_64-DVD-1810.iso

Create a network in the host for the private use of the PXE process

cat > ${PXE_STAGE}/pxe-net.xml <<EOF
<network>
  <name>pxe-net</name>
  <bridge name="pxe-br0" />
  <forward/>
  <ip address="192.168.40.1" netmask="255.255.255.0" />
</network>
EOF

sudo virsh net-define ${PXE_STAGE}/pxe-net.xml
sudo virsh net-autostart pxe-net
sudo virsh net-start pxe-net

Create the PXE guest

mkdir -p ${PXE_STAGE}/guests/pxe/

virt-install \
 -n pxe \
 -v \
 --description="PXE machine" \
 --os-type=Linux \
 --os-variant=generic \
 --ram=512 \
 --vcpus=1 \
 --graphics=vnc \
 --disk path=${PXE_STAGE}/guests/pxe/pxe.img,bus=virtio,size=10 \
 --cdrom=${PXE_STAGE}/${CENTOS_ISO} \
 --network=bridge:pxe-br0,model=virtio,mac=52:54:00:e2:87:5a

Install Linux Centos7 using VNC

When the guest boots will present a graphical interface, the PXE server is installed with the minimum packages

To start de installation vncviewer should be used:

vncviewer :0

• IP: 192.168.40.10
• Gateway: 192.168.40.1
• DNS: 192.168.40.1
• Hostname: pxe.demobox.local
• Root password: Welcome1
• Keyboard:
• Timezone:

Get host IP to run the playbook against the guest

for mac in `virsh domiflist pxe |grep -o -E "([0-9a-f]{2}:){5}([0-9a-f]{2})"` ; do  ip n  |grep $mac  |grep -o -P "^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}" ; done

Copy my ssh key to the host (have to make this better)

ssh-keygen -R 192.168.40.10 -f ~/.ssh/known_hosts
ssh-keyscan -t rsa 192.168.40.10 >> ~/.ssh/known_hosts
ssh-copy-id [email protected]

Stop the guest to release the console

ssh [email protected] shutdown -h now

Attach the CDROM to the guest, is will be used to serve the installation files

cat > ${PXE_STAGE}/pxe-cdrom.xml <<EOF
<disk type='block' device='cdrom'>
  <driver name='qemu' type='raw'/>
  <source dev='${PXE_STAGE}/${CENTOS_ISO}'/>
  <target dev='hda' bus='ide'/>
  <readonly/>
</disk>
EOF

virsh update-device pxe ${PXE_STAGE}/pxe-cdrom.xml

virsh domblklist pxe

Start again the server (will run in background)

virsh start pxe

Execute Ansible playbook to configure the server

Adjust the hosts file to the environment you plan to use

The hosts_names is a list of guest to be installed, the mac addresses should match with the parameter --network network=pxe-net,model=virtio,mac=52:54:00:e2:87:5c in the virt-install

    pxeservers:
      hosts:
        192.168.122.219:
        
        hosts_names: ["pxe-boot","pxe-master1","pxe-agent1"]
        hosts_ips: ["192.168.30.100","192.168.30.101","192.168.30.102"]
        hosts_mac_addrs: ["52:54:00:e2:87:5c","52:54:00:e2:87:5d","52:54:00:e2:87:5e"]
        hosts_roles: ["boot","master","agent"]

Run the playbook from the base of the project clone

ansible-playbook -i conf/hosts pxe.yml

Stop the guest to apply the changes in the enterprise Linux

ssh [email protected] reboot

Cleanup

If need to clean up the pxe server

virsh destroy pxe;virsh undefine pxe;rm -rf ${PXE_STAGE}/guests/pxe/

If need to remove the network

virsh net-destroy pxe-net
virsh net-undefine pxe-net

Now the guests for the other applications can be created

Some other commands

• Insert a cdrom in the guest drive: virsh change-media pxe hda --insert /opt/stage/CentOS-7-x86_64-DVD-1708.iso
• Eject the cdrom: virsh attach-disk pxe " " hda --type cdrom --mode readonly
• Start a guest: virsh start pxe
• List the block devices of a guest: virsh domblklist pxe
• List the network devices of a guest: virsh domiflist pxe-boot