openshift-home-lab

Sample script to build a KVM environment for OpenShift 3.10 in my homelab

...This README needs updating for 3.10...

I (irc: MarcNo) needed to setup a local OpenShift environment for experimentation on a local desktop with 32GB memory. These config files work for me to do a simple install of OpenShift.

If you want to do the same, here are some scripts and configuration files to help get you going.

This is still a bit rough and requires some editing of files. Please send patches/PR.

Thanks to mmagnani and ruchika for kickstarting the initial work.

What do you get

• Three RHEL7.3 VMs running in KVM
• Registered and appropriate subscriptions attached
• required RPMs installed, including atomic-openshift-installer
• docker installed and storage configured
• ready to install the OpenShift cluster from the jump VM.

Requirements

• Access to DNS server. I'm using a personal domain hosted on domains.google.com.
• Access to DHCP server. I'm using my home MikroTik router and tie specific IP addresses to known mac addresses. ie: VMs always get the same IP address from DHCP.
• RHEL 7 KVM hypervisor host
• rhel-guest-image-7.3-35.x86_64.qcow2 (from https://access.redhat.com/downloads/)
• 2 NICs on your hypervisor. I use an onboard NIC plus an inexpensive USB NIC.

editing scripts

You should only have to edit one configuration file, env.sh

edit various files

• Edit env.sh for your environment:

  • DOMAIN - the domain name to use for the hosts (ie: gwiki.org)
  • MACADDRESS - MAC addresses for your VMs (be unique)
  • OCPDOMAIN - the domain name for the cluster (ie: ocp.nozell.com, *.apps.nozell.com)
  • WORKSPACE, VMS - where VMs, etc are stored
  • ISOS - where your ISOs can be found
  • RHEL_IMAGE - your rhel-guest-image-7.3-35.x86_64.qcow2 is
  • BRIDGE - which bridge to use. See Network Notes below

• Update your DNS server. Google hosts my DNS records, so I don't need to hack /etc/resolv.conf. But you will need to update your DNS A records to point to the local addresses so it looks like this. eg:

    $ nslookup jump.$DOMAIN
    Server:		8.8.8.8
    Address:	8.8.8.8#53
    
    Non-authoritative answer:
    Name:	jump.$DOMAIN
    Address: 192.168.88.99
  

Also setup wildcard DNS entry for *.ocp.$OCPDOMAIN, *.apps.$OCPDOMAIN to point to the master0.$OCPDOMAIN

• Update your DHCP server

Tie those specific IP addresses defined in DNS to known mac addresses. ie: VMs always get the same IP address from DHCP.

Network Notes

Getting the network setup properly is a trick. You can use the default virb0 bridge that KVM automatically sets up, but that will only allow the VMs be connected to from the hypervisor or other VMs on the same host.

I want to be able to connect to the individual VMs from any system, so I added a second NIC in the form of an inexpensive USB 3 NIC (enp0s20f0u1)

Here are the NetworkManager CLI commands to create another bridge (br0) and have enp0s20f0u1 bound (aka slaved) to it.

nmcli con add type bridge ifname br0

nmcli con show # some will be yellow

nmcli -f bridge con show bridge-br0 # just take a look

nmcli con add type bridge-slave ifname enp0s20f0u1 master br0

ifup br0

nmcli con show # all green

Then edit /etc/qemu-kvm/bridge.conf to add:

allow br0

Optional just finishing up libvirt config

virsh net-list --all

If you don't see a default network entry from the previous command, do this:

virsh net-define /usr/share/libvirt/networks/default.xml

virsh net-start default

virsh net-autostart default

edit variables.yml

• You need to set the openshift_subscription_pool for your own Red Hat account. Use this command will find your pool id:

  subscription-manager list --all --available --matches "*openshift*"

  Make variable.yml look something like this:

  openshift_subscription_pool: 8a85f9833e1404a9013e3cddf95a0599

create ansible-vault vault.yml

• Create a vault to store your own Red Hat subscription username/password in variables. (ie: what you use on the Red Hat portal)

  ansible-vault create vault.yml

  Make variable.yml look something like this:

  vault_rhn_username: my-rhn-support-username

  vault_rhn_password: secretpassword-for-rhn

  Take a look at the resulting file and it should not have the variables in cleartext.

Run on your hypervisor

• 0-generate.sh -- Create hosts and hosts.ocp based on your env.sh settings
• 1-create.sh -- Create qemu files for OS, container storage, OS config
• 2-build.sh -- Install VMs and attach disks
• start-all.sh -- boot them up
• 3-keys.sh -- push ssh keys around
• 4-prep.sh -- update the VMs with required packages, etc
• 5-cluster.sh -- copy files to jump VMs and remind the next steps

Post configuration

Install OpenShift

• hypervisor# ssh [email protected] # password is redhat

• jump# ssh-keygen

• jump# bash ./3-keys.sh

• jump# ansible-playbook -i hosts.ocp /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml

• Once the cluster is created, ssh root@master0 and create a non-admin user:

  # touch /etc/origin/master/htpasswd

  # htpasswd /etc/origin/master/htpasswd someuser

Start using OpenShift

The easiest way to get started is to point a browser to https://ocp.$OCPDOMAIN:8443/ (in my example, https://ocp.nozell.com:8443)

TODO

• fix warning messages from ansible (replace sudo with become/become_user/become_method, service module, etc)