OCPv4 UPI HelperNode

Description:The main point of the helpernode is to simplify the prerequisites needed for a Bare Metal UPI install

In this live stream, Christian Hernandez will walk through what helpernode is, how to get the helpernode up and running, and getting and OpenShift 4 cluster stood up with helpernode's assistance.

https://github.com/RedHatOfficial/ocp4-helpernode

Transcript

1. OCPv4 UPI HelperNode
   And what it can do for you!
   

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2. Challenge - You need more prereqs with 4.x
   ● DNS entries
   ○ Wildcard
   ○ Forward/Reverse records for hosts
   ○ SRV records (no longer needed for 4.4+)
   ● Load Balancer
   ○ Internal API
   ○ External API
   ○ Machine Config API
   ○ Router
   ■ 80/443
   ● Web Server
   ○ Used during install
   ○ Host RHCOS bios files
   ○ Host ignition files
   ● DHCP
   ○ Docs State Static IPs aren’t supported
   ■ It is supported
   ○ “Static DHCP” is recommended
   ○ It’s, in fact, very easy
   ■ But not very common with
   customers.
   ● PXE
   ○ You can boot via ISO
   ○ If using Virtualization; you can use “HTTP
   Install”
   ■ Might be useful for customers that
   add/remove hosts often
   ● Install host
   ○ AKA a “bastion” server
   

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3. HelperNode Playbook to the rescue!
   ● Meant to help you with the install
   ○ Doesn’t do the install for you
   ● Takes care of a LOT of he prereqs
   ○ DNS
   ○ DHCP
   ○ PXE/TFTP
   ○ HAProxy
   ○ HTTPD
   ○ Bastion Host
   ○ Client Tools
   ○ Podman
   ● Has two “modes”
   ○ Standard/DHCP (default)
   ○ Static IPs
   ● Built/tested on Libvirt
   ○ Libvirt NOT required
   ○ Agnostic to the environment
   ● Keep relatively up to date
   ○ Standardizing on every other Z stream
   ■ 4.y.z
   ○ After install just click the “update” button :)
   ● Meant for “lab” environments
   ○ You CAN use it for customers to do POCs
   ○ Probably will never be supported by RH
   ● Built on CentOS 7/8
   ○ Should work on RHEL7/8
   https://github.com/RedHatOfficial/ocp4-helpernode
   

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4. MASTER
   WORKER
   NETWORK
   You
   Your Laptop
   ● DNS Server
   ● Load Balancer
   ● Web Server
   ● Bastion Host
   ● DHCP
   ● PXE
   ● TFTP
   ● NFSv4
   Helper DNS
   DNS Delegation
   (Optional)
   ???
   ???
   ???
   Other, ancillary,
   services/servers not needed
   for the HelperNode. That
   you may have in your
   environment
   MASTER
   MASTER
   WORKER
   WORKER
   3 Masters
   Minimum of
   2 Workers
   

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5. Demo Environment
   Me
   My Laptop
   Virt Server
   ● Virt Server is running Libvirt
   ○ With virt-* tools installed
   ● 8vCPUs
   ○ But I suggest 12 vCPUs
   ● 64 GB RAM
   ● 1TB HD
   ○ store virtual Machines
   ● RHEL 8 64bit
   ● VNC Viewer HIGHLY recommended
   SSH/VNC
   INSIDE THE VIRT SERVER
   NAT
   Internet
   Virtual Network “openshift4”
   N
   M M M
   N
   H
   192.168.7.0/24
   

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6. Anyway...on with the install!
   

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7. OpenShift 4 install workflow (regardless of IPI/UPI)
   

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8. Disconnected
   

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9. WORKER
   MASTER MASTER MASTER
   WORKER
   WORKER
   REGISTRY
   LB
   ???
   ???
   ???
   Ancillary Services:
   DNS
   DHCP
   Apache
   ... Restricted network
   Connected Network
   (Full Internet Access)
   OpenShift Cluster
   Two Network Interfaces Quay and other
   Red Hat Services
   Internet
   Registry will mirror
   repos from Red Hat
   and serve them
   

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