How to Create Cluster 7 (Ubuntu 20.04)

Introduction

Here are the instructions on how to build Cluster 7 using Ubuntu 20.04.

The build is not complete as of October 19, 2021.

Hardware Requirements (so far)

• 2 x 1 gigabit unmanaged switches

• one switch for private IP
• one switch for public IP

• 4 x unused ProLiant DL160 G5 Machines

• one for NAT machine
• one for Foreman Server
• one for LDAP Server
• one extra for any testing

• 1 x USB for Operating System (OS)

Create a Network Address Translation(NAT) machine

A NAT machine will act as a local VPN to the cluster. This will be the first machine you SSH into.

Current machine:

• Hostname: segundo.dot
• IP Address: 10.70.1.2

Instructions

1. Install Ubuntu 20.04 using USB. You can set everything to default but make sure to disable network interfaces if DHCP Server is not set up yet.
2. After OS installation, grab MAC Address of network interface enp4s0. You'll need it to make a public IP.
   • ip a
3. Create a DNS entry for this machine in the website below to give you a public IP address
   • https://www.cgl.ucsf.edu/cgi-bin/secure/dns_dhcp_registration.py?action=view_zone&name=compbio.ucsf.edu
4. File a ticket to UCSF IT to open port 22 on the public interface
   • https://ucsf.service-now.com/ucsfit?id=ucsf_sc_cat_item&sys_id=10ea7459e0cef000e2dc0adb442e954c&sysparm_category=6654dac6877050009b5428676d434dec
5. Configure private and public network interfaces
   • vim /etc/netplan/00-installer-config.yaml
   • Configuration should look like this:

   # This is the network config written by 'subiquity'

   network:

   ethernets:

   enp3s0:

   addresses:

   - 10.70.1.2/16

   gateway4: 127.0.0.1

   nameservers:

   addresses:

   - 10.70.1.1

   search:

   - dot

   enp4s0:

   addresses:

   - 169.230.26.58/16

   gateway4: 169.230.26.1

   nameservers:

   addresses:

   - 8.8.8.8

   - 8.8.4.4

   - 128.218.254.10

   - 128.218.254.40

   search:

   - dot

   - compbio.ucsf.edu

   version: 2

6. Test if configuration works by pinging google
   • ping google.com
7. Enable and allow ssh in UFW firewall
   • ufw enable
   • ufw allow ssh
   • ufw status
8. Enable NAT in UFW
   • vim /etc/default/ufw
     • Change parameter of "DEFAULT_FORWARD_POLICY" to "ACCEPT"
   • vim /etc/ufw/sysctl.conf
     • Uncomment "net.ipv4.ip_forward=1"
   • vim /etc/ufw/before.rules
     • Add these lines at the beginning of the file:

   # NAT table rules

   *nat

   :POSTROUTING ACCEPT [0:0]

   -A POSTROUTING -s 169.230.26.58/16 -o enp4s0 -j MASQUERADE

   COMMIT

   • ufw reload
9. Test by setting another machine's gateway to 10.70.1.2