Setting up CentOS on VirtualBox for RDO

Create a CentOS Virtual Machine (VM)

NOTE: There are several different ways in creating a base VM CentOS image. These steps are the more manual approach, however they are provided for completeness in understanding varying options.

To create a virtual machine in VirtualBox select the New icon. This will prompt you for some initial configuration. Use these recommendations:

  • Name and operating System
    • Name: RDO
    • Type: Linux
    • Version: Red Hat (64-bit)
  • Memory Size
    • Use at minimum 4GB.
  • Hard Disk
    • Use the default settings including 8.0GB, VDI type, dynamically allocated, File location and size.

By default your virtual machine is ready to install however by making the following network recommendation it will be easier to access your running virtual machine via SSH and the RDO web interface and APIs from your host computer.

  • Click Settings
  • Select Network
  • Enable Adapter 2 and attach to a Host-only Adapter and select vboxnet0
  • Ok

Install CentOS Operating System

You are now ready to install the Operating System on the virtual machine with the following instructions.

  • Click Start
  • Open the CentOS .iso file you just downloaded.
  • You will be prompted for a number of options, select the default provided and use the following values when prompted.
  • Install CentOS 7
  • Select English and English (United States) (or your choice of language)
  • Select System to configure your installation destination
    • Click Done to use the default VM disk and automatically configure partitioning
  • Select Network & hostname
    • Enable both of the listed Ethernet connections
    • Enter rdo for the Host Name
    • Click Done
  • Click Begin Installation
  • Click Root Password
    • Enter password of your choosing
  • Click User Creation
    • Enter rdo for user name (or any value of your choice)
    • Enter Openstack for password (or any password of your choice)
    • Click Done

When the installation is complete, click Reboot.

You will now be able to login with username: rdo and password: Openstack (or the values you chose).

Post Installation

While the second ethernet adapter for your VM is configured it is not enabled.

$ su -
# Enter root password
$ sed -ie "s/ONBOOT=no/ONBOOT=yes/" /etc/sysconfig/network-scripts/ifcfg-enp0s8
$ ifup enp0s8
$ ip addr
# RDO does not operate with NetworkManager
$ sudo systemctl stop NetworkManager.service
$ sudo systemctl disable NetworkManager.service

The ip output will verify the IP address that was assigned. If you configured the VirtualBox host-only adapter with defaults, the address will be 192.168.56.1XX.

To verify access to your virtual machine from your host computer, you should SSH with:

$ ssh rdo@192.168.56.1XX

VirtualBox networking for beginners

When using VirtualBox for my OpenStack development I always configure two network adapters for ease of development. The first is a NAT adapter that enables the guest VM connectivity to the Internet via the host. The second network adapter is a host-only Adapter that enables my host computer (aka my terminal windows) to SSH directly to the guest VM, or to access a web interface for example. This enables the use of tools like ssh, scp, rsync etc easily with multiple VMs without thinking of different ports.

Having the two adapters is very convenient, however when you install products such as devstack or RDO these require additional steps to manage the interface and configure the installation. These steps are relatively straightforward but they make the most simple instructions more complex.

There are alternatives to using the NAT only adapter and enable port forwarding. For example you can configure port forwarding of port 2222 to the guest 22 with (when VM is not running):

$ VBoxManage modifyvm "vm-name" --natpf1 "guestssh,tcp,,2222,,22"
$ VBoxManage startvm "vm-name"

You can now connect to the guest VM via port forwarding on your host, in this case connecting to port 2222.

$ ssh user@localhost -p 2222

Personally I find this a disadvantage. You need to provide port forwarding for all ports you want to communicate on e.g. ssh (22), http (80) and keystone (5000). You need to do it in advance of using your VM, and you also need to do this for each VM.

However, depending on your needs and experience this is a valid alternative.

Ubuntu two adapter configuration

On Ubuntu, the following configuration file defines two DHCP network adapters.

$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet dhcp

You can verify adapter information (e.g. IP address) using ifconfig.

$ ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:7f:a0:e2  
          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe7f:a0e2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:585 errors:0 dropped:0 overruns:0 frame:0
          TX packets:455 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:129820 (129.8 KB)  TX bytes:64215 (64.2 KB)

eth1      Link encap:Ethernet  HWaddr 08:00:27:66:8d:cb  
          inet addr:192.168.56.102  Bcast:192.168.56.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe66:8dcb/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:221 errors:0 dropped:0 overruns:0 frame:0
          TX packets:152 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:28289 (28.2 KB)  TX bytes:19443 (19.4 KB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:371 errors:0 dropped:0 overruns:0 frame:0
          TX packets:371 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:90509 (90.5 KB)  TX bytes:90509 (90.5 KB)

The ip command is also available.

To configure an IP with a fixed address on the host-only adapter network which is useful for many machines, you would use:

auto eth1
iface eth1 inet static
address 192.168.56.50
netmask 255.255.255.0
gateway 192.168.56.1

CentOS two adapter configuration

CentOS keeps a configuration file per interface. We start be determining the interface names.

$ ls -l /etc/sysconfig/network-scripts/ifcfg-*
-rw-r--r--. 1 root root 310 Mar 30 16:53 /etc/sysconfig/network-scripts/ifcfg-enp0s3
-rw-r--r--. 1 root root 278 Mar 30 17:00 /etc/sysconfig/network-scripts/ifcfg-enp0s8
-rw-r--r--. 1 root root 277 Mar 30 16:53 /etc/sysconfig/network-scripts/ifcfg-enp0s8e
-rw-r--r--. 1 root root 254 Sep 16  2015 /etc/sysconfig/network-scripts/ifcfg-lo

And then can review the per interface configuration with:

$ cat /etc/sysconfig/network-scripts/ifcfg-enp0s3
TYPE="Ethernet"
BOOTPROTO="dhcp"
DEFROUTE="yes"
PEERDNS="yes"
PEERROUTES="yes"
IPV4_FAILURE_FATAL="no"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
IPV6_DEFROUTE="yes"
IPV6_PEERDNS="yes"
IPV6_PEERROUTES="yes"
IPV6_FAILURE_FATAL="no"
NAME="enp0s3"
UUID="2c0bdd66-badc-449c-8db8-b2c85a716dab"
DEVICE="enp0s3"
ONBOOT="yes"

$ cat /etc/sysconfig/network-scripts/ifcfg-enp0s8
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_FAILURE_FATAL=no
NAME=enp0s8
UUID=4127685d-a7b9-4b8d-a399-6dcacdb3396d
DEVICE=enp0s8
ONBOOT=yes

You can verify the network configuration using the ip command.

$ ip addr
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s3:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:32:c0:4c brd ff:ff:ff:ff:ff:ff
    inet 10.0.2.15/24 brd 10.0.2.255 scope global dynamic enp0s3
       valid_lft 15876sec preferred_lft 15876sec
    inet6 fe80::a00:27ff:fe32:c04c/64 scope link 
       valid_lft forever preferred_lft forever
3: enp0s8:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:43:22:85 brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.103/24 brd 192.168.56.255 scope global dynamic enp0s8
       valid_lft 1056sec preferred_lft 1056sec
    inet6 fe80::a00:27ff:fe43:2285/64 scope link 
       valid_lft forever preferred_lft forever

CentOS does not provide ifconfig by default, it’s included in the net-tools package (RDO for example installs this).

$ sudo yum install -y net-tools
$ ifconfig
enp0s3: flags=4163  mtu 1500
        inet 10.0.2.15  netmask 255.255.255.0  broadcast 10.0.2.255
        inet6 fe80::a00:27ff:fe32:c04c  prefixlen 64  scopeid 0x20
        ether 08:00:27:32:c0:4c  txqueuelen 1000  (Ethernet)
        RX packets 437445  bytes 441847285 (421.3 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 142720  bytes 8897712 (8.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp0s8: flags=4163  mtu 1500
        inet 192.168.56.103  netmask 255.255.255.0  broadcast 192.168.56.255
        inet6 fe80::a00:27ff:fe43:2285  prefixlen 64  scopeid 0x20
        ether 08:00:27:43:22:85  txqueuelen 1000  (Ethernet)
        RX packets 14250  bytes 1708162 (1.6 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 15367  bytes 13061787 (12.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10
        loop  txqueuelen 0  (Local Loopback)
        RX packets 5706360  bytes 778262566 (742.2 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 5706360  bytes 778262566 (742.2 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

References

Setting up a Virtual IP address (VIP)

These instructions are for CentOS/Redhat Linux distributions.

1. Identify your current NIC’s and IP addresses in use.

$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 00:30:48:98:9C:A6
          inet addr:192.168.53.201  Bcast:192.168.53.255  Mask:255.255.255.0
          inet6 addr: 0080::230:48ff:fe98:9ca6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6159779 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6137085 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:1158210510 (1.0 GiB)  TX bytes:541617489 (516.5 MiB)
          Memory:e8000000-e8020000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:3791468208 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3791468208 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:740660664181 (689.7 GiB)  TX bytes:740660664181 (689.7 GiB)

Determine which NIC you want the VIP on, in this case eth0 (the private address). We want to add the address 192.168.53.220

$  echo "DEVICE=eth0
BOOTPROTO=static
BROADCAST=192.168.53.255
IPADDR=192.168.53.220
NETMASK=255.255.255.0
NETWORK=192.168.53.0
ONBOOT=yes" > /etc/sysconfig/network-scripts/ifcfg-eth0:0
$ /etc/sysconfig/network-scripts/ifup-aliases eth0

Check your /sbin/ifconfig and now you should have a virtual IP address.

$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 99:30:48:98:9C:A6
          inet addr:192.168.53.201  Bcast:192.168.53.255  Mask:255.255.255.0
          inet6 addr: 0080::230:48ff:fe98:9ca6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6159779 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6137085 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:1158210510 (1.0 GiB)  TX bytes:541617489 (516.5 MiB)
          Memory:e8000000-e8020000

eth0:0    Link encap:Ethernet  HWaddr 99:30:48:98:9C:A7
          inet addr:192.168.53.220  Bcast:192.168.53.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Memory:e8100000-e8120000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:3791468208 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3791468208 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:740660664181 (689.7 GiB)  TX bytes:740660664181 (689.7 GiB)