Lab template: CentOS 7.2

Posted on September 19, 2016 by brian.wuchner

Recently I’ve been working in a couple of different / disconnected labs. This means I’m managing a couple copies of all my templates manually. Sometimes its hard to find the right section of my notes depending on when/where I’m working on the lab, so I decided to post a couple quick blog posts so I can always find them. The following notes are for creating a template based on CentOS 7.2, and include notes on setting a static IP and joining to the domain with pbis-open (formerly likewise-open).

Special thanks to http://www.tecmint.com/things-to-do-after-minimal-rhel-centos-7-installation/… which showed me how to get ifconfig in my minimal install. I’m not sure who decides what makes the cut for minimal installations, but ifconfig and nslookup seem like they should be in to me.

Install CentOS 7.2 Minimal install from ISO image (http://isoredirect.centos.org/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1511.iso), accepting all defaults. Create an administrator account named hostadmin during the install.

Once the install is complete, login as hostadmin. Switch to root and set a password for the root user.

sudo su -
passwd

In my testing, the VM did not get an IP address from DHCP, even though DHCP was available and working. To get online I had to change ONBOOT=no to ONBOOT=yes in the file:

vi /etc/sysconfig/network-scripts/ifcfg-eno16777984

I then restarted networking to bring the interface back up with an IP:

service network restart

Now that I have an IP, I update/upgrade my installation and install some handy/useful packages:

yum update && yum upgrade
yum install net-tools bind-utils nano ntp wget -y

Get the template ready for PowerBroker Identity Services (formerly likewise-open) domain joins:

rpm --import http://repo.pbis.beyondtrust.com/yum/RPM-GPG-KEY-pbis
wget -O /etc/yum.repos.d/pbiso.repo http://repo.pbis.beyondtrust.com/yum/pbiso.repo
yum clean all
yum install pbis-open

At this point, I shutdown the VM and convert it to a template. When I’m ready to use the VM, I deploy a copy from template and follow the remaining steps.

If needed, set a static IP by updating the following file… this is the same file we edited earlier to enable DHCP:

nano /etc/sysconfig/network-scripts/ifcfg-eno16777984

For Static IP, remove bootproto=dhcp, and add the following

IPADDR="192.168.0.101"
PREFIX="24"
GATEWAY="192.168.0.1"
DNS1="192.168.0.20"
SEARCH="lab.enterpriseadmins.org"

Verify that the hostname is properly set:

nano /etc/hostname

Join the Linux VM to the domain and create a DNS record:

domainjoin-cli join lab.enterpriseadmins.org adminbw
/opt/pbis/bin/config AssumeDefaultDomain true
/opt/pbis/bin/config LoginShellTemplate /bin/bash
/opt/pbis/bin/config HomeDirTemplate %H/%U
/opt/pbis/bin/config RequireMembershipOf "lab\\domain^users"
/opt/pbis/bin/update-dns

Once I reach this point, I kick off a quick reboot (just to make sure the domain join took) and am now free to use the VM.

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Lab template: Ubuntu 16.04

Posted on September 19, 2016 by brian.wuchner

Recently I’ve been working in a couple of different / disconnected labs. This means I’m managing a couple copies of all my templates manually. Sometimes its hard to find the right section of my notes depending on when/where I’m working on the lab, so I decided to post a couple quick blog posts so I can always find them. The following notes are for creating a template based on Ubuntu 16.04.1, and include notes on setting a static IP and joining to the domain with pbis-open (formerly likewise-open).

Install Ubuntu 16.04.1 Server from ISO image (http://www.ubuntu.com/download/server/thank-you?version=16.04.1&architecture=amd64), accepting all defaults. When prompted for an admin user, use the name hostadmin.

Once the install is complete, login as hostadmin. Switch to root and set a password for the root user.

sudo su -
passwd

Apply updates and install the packages openssh-server and ntp:

apt-get update && apt-get upgrade
apt-get install openssh-server ntp -y

Get the template ready for PowerBroker Identity Services (formerly likewise-open) domain joins:

wget http://download1.beyondtrust.com/Technical-Support/Downloads/PowerBroker-Identity-Services-Open-Edition/pbiso/850/pbis-open-8.5.0.153.linux.x86_64.deb.sh
chmod +x pbis-open-8.5.0.153.linux.x86_64.deb.sh
./pbis-open-8.5.0.153.linux.x86_64.deb.sh
cd /opt/pbis/bin/ 

At this point, I shutdown the VM and convert it to a template. When I’m ready to use the VM, I deploy a copy from template and follow the remaining steps.

If needed, set a static IP by updating the following file:

nano /etc/network/interfaces

The important sections to include in the iface settings are address, netmask, gateway, dns-search, and dns-nameservers. An example has been included below:

iface eth0 inet static
address 192.168.0.100
netmask 255.255.255.0
gateway 192.168.0.1
dns-search lab.enterpriseadmins.org
dns-nameservers 192.168.0.20

Verify that the hostname is properly set:

nano /etc/hostname

Join the Linux VM to the domain and create a DNS record:

domainjoin-cli join lab.enterpriseadmins.org adminbw
/opt/pbis/bin/config AssumeDefaultDomain true
/opt/pbis/bin/config LoginShellTemplate /bin/bash
/opt/pbis/bin/config HomeDirTemplate %H/%U
/opt/pbis/bin/config RequireMembershipOf "lab\\domain^users"
/opt/pbis/bin/update-dns

Once I reach this point, I kick off a quick reboot (just to make sure the domain join took) and am now free to use the VM.

Posted in Virtualization | 1 Comment

Reload syslog configuration on ESXi

Posted on June 13, 2016 by brian.wuchner

I recently updated Log Insight to version 3.3.2 in my lab. After selecting the appropriate PAK file, the UI displayed a warning containing the following text:

Note that certain builds of ESXi need to have 
their syslog configuration reloaded after restart, 
otherwise log data will stop forwarding. 
Configuration can be reloaded from the vSphere 
Integration page. See the Online Help for 
more information.

I waited a couple hours after the upgrade to check back on the system and noticed that I was no longer collecting syslog data. I visited the vSphere Integration page and reviewed my hosts, but they were already configured as expected. I picked just one host and updated the configuration anyway, and that host started logging data again. For another host, I manually cleared the syslog.global.logHost value from the web client and then re-entered the logHost text. This also caused the host to start sending syslog data again. Interested in the minimum effort to ‘reload’ syslog configuration (without needing to update/reset logHost values) I found the following KB article: https://kb.vmware.com/kb/2003322. It appears that esxcli has an option to simply reload the configuration (using esxcli system syslog reload). To run this on all hosts remaining in my inventory, I executed the following code:

Get-VMHost | Sort-Object Name | %{
  write-host -nonewline "$($_.Name) reloading syslog:"
  (Get-EsxCli -VMHost $($_.Name) -v2).system.syslog.reload.invoke()
}

Note: this requires the latest version (6.3 release 1) of PowerCLI. I hope someone finds this information helpful.

Posted in Scripting, Virtualization | Leave a comment

Find ESXi Installation Date with PowerCLI

Posted on January 10, 2016 by brian.wuchner

I recently noticed a link to a very interesting article on Twitter: Find ESXi Installation Date — http://vcdx56.com/2016/01/05/find-esxi-installation-date/. These steps are straight forward and show how to calculate the original ESXi install date, looking at the first section of the UUID. I didn’t realize so much useful information was coded into the UUID, but this could be useful information for certain reports. To understand the process, please check out the original article on vcdx56.com.

The following few lines of code will return this information for all hosts in a vCenter using PowerCLI.

# Find ESXi install date: http://vcdx56.com/2016/01/05/find-esxi-installation-date/
# Convert HEX to DEC: http://michaelflanakin.com/Weblog/tabid/142/articleType/ArticleView/articleId/1073/Converting-ToFrom-Hex-with-PowerShell.aspx
# Convert epoch to date: http://stackoverflow.com/questions/10781697/convert-unix-time-with-powershell

Get-VMHost | Sort Name | %{
  $thisUUID = (Get-EsxCli -VMHost $_.name).system.uuid.get()
  $decDate = [Convert]::ToInt32($thisUUID.Split("-")[0], 16)
  $installDate = [timezone]::CurrentTimeZone.ToLocalTime(([datetime]'1/1/1970').AddSeconds($decDate))
  [pscustomobject][ordered]@{
    Name="$($_.name)"
    InstallDate=$installDate
  } # end custom object
} # end host loop
Posted in Scripting, Virtualization | 1 Comment

Do you have any way of getting IPs from a list of server names?

Posted on August 10, 2015 by brian.wuchner

A few days ago, someone asked a very basic question. Where is the opposite version of this script:
http://enterpriseadmins.org/blog/scripting/do-you-have-any-way-of-getting-server-name-from-the-attached-list-of-ips/? They had a list of host names and wanted the associated IP addresses. Since it is somewhat common for a name to resolve to multiple IP addresses, this function has a few more lines as it will loop through each result.

Function Get-HostIP ([string]$hostName) {
  try {
    [system.net.dns]::GetHostByName($hostName).AddressList | %{
      New-Object psobject -Property @{
        HostName = $hostName
        IPAddress = $_.IPAddressToString
      } # End result object
    } # end foreach loop
  } catch {
    New-Object psobject -Property @{
      HostName = $hostName
      IPAddress = "Unknown/Error"
    } # end result object
  } # end try/catch
} # end function

Here is a sample result running this function against google.com:

Get-HostIP 'google.com'

IPAddress     HostName
---------     --------
173.194.46.67 google.com
173.194.46.71 google.com
173.194.46.65 google.com
173.194.46.66 google.com
173.194.46.69 google.com
173.194.46.72 google.com
173.194.46.70 google.com
173.194.46.78 google.com
173.194.46.68 google.com
173.194.46.73 google.com
173.194.46.64 google.com
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