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Implementing log rotation for the Jamf Infrastructure Manager logs on Red Hat Enterprise Linux

November 4, 2017 Leave a comment

A while back, I had set up the Jamf Infrastructure Manager (JIM) in a VM running Red Hat Enterprise Linux (RHEL) to provide a way for a Jamf Pro server hosted outside a company’s network to be able to talk to an otherwise inaccessible Active Directory domain. The JIM software has been running fine since I configured it, but I recently needed to take a look at the JIM logs as part of diagnosing another issue.

For those not familiar with the JIM software, it has several log files and those logs are available in the following location on RHEL:

/var/log/jamf-im-launcher.log
/var/log/jamf-im.log
/var/log/jamf-im-pre-enroll.log

Screen shot 2017 04 29 at 5 32 52 pm

When I checked the logs, I noticed that /var/log/jamf-im.log had grown to almost 500 MBs in size.

Considering this log is a plaintext file, that’s a big log file and it seemingly had been not been rotated or otherwise changed since I first installed the JIM software. To help make sure that the host VM would not eventually run out of space because of this growing log file, I needed to implement log rotation for the JIM logs. For more details, see below the jump.

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Managing AWS-hosted VMs using EC2 Systems Manager

May 30, 2017 Leave a comment

I’ve been doing a lot of work recently with Linux VMs that are hosted on Amazon Web ServicesEC2 service. As part of this work, I’ve been working on two problems in parallel:

  • Enabling automation of certain management commands for the VMs
  • Securing SSH

Part of the issue was that I thought I needed to have SSH available to enable remote administration. If that was true, I also needed to secure SSH access so that I could use it and malicious third parties couldn’t. However, whatever method I chose also needed to be easily accessible to my team so that they could access the AWS-hosted VMs in case of an emergency where I wasn’t available.

I went through a few iterations of SSH solutions, including investigating multi-factor authentication and setting up SSH bastions. In the end though, I discovered a surprising solution that fixed both of my problems: AWS’s EC2 Systems Manager

Systems Manager allowed me to do the following:

  1. Manage my Linux VMs on EC2 without using SSH
  2. Block SSH access on my Linux VMs
  3. Run commands on multiple VMs at once
  4. Create a library of frequently used tasks and run those commands without needing to re-enter the scripts used to run those tasks.
  5. Not spend extra money on a management solution because AWS makes Systems Manager available at no cost to AWS customers.

For more details, please see below the jump.

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Installing and configuring the Jamf Infrastructure Manager on Red Hat Enterprise Linux

April 29, 2017 4 comments

I recently needed to configure Jamf’s Jamf Infrastructure Manager (JIM) to provide a way for a Jamf Pro server hosted outside a company’s network to be able to talk to an otherwise inaccessible Active Directory domain.

The documentation on how to set up an Infrastructure Manager covers the essentials of how to do it, but doesn’t include any screenshots or have information about how to access the logs to help debug problems. After some research and working with the JIM a bit, I was able to figure out the basics. For more details, see below the jump.

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Using IAM roles on Amazon Web Services to generate temporary credentials for EC2 instances

April 27, 2017 Leave a comment

While working on a project involving Amazon Web Services, I ran across the concept of being able to use temporary credentials with AWS’s Command Line Interface (awscli) tool. When using the awscli tool, it is necessary to provide authentication credentials so that the aws tool is able to authorize its actions with AWS. When running the awscli tool on an EC 2 instance, AWS has provided a way to get temporary authentication credentials on demand, through the use of IAM roles.

In my research on the topic, I found a lot of posts showing how to use temporary credentials, but not a lot of information on how to set up the needed IAM roles. After some additional research, in addition to trial and error, I was able to figure out the IAM role setup process. For more details, see below the jump.

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Categories: Amazon Web Services, Linux

Performance tuning for the Casper JSS

April 17, 2016 1 comment

One of the challenges Casper admins can run into is performance tuning, which can require going into parts of the JSS that you normally go into only when JAMF Support asks you to do so. To help with this process, there are formulas which you can use to calculate if your JSS’s Tomcat and MySQL services are configured for best performance.

Before proceeding further, I want to emphasize that a) check with JAMF Support first and b) you should always, always, always make backups of your JSS before changing settings. I assume no responsibility and bear no culpability if your JSS breaks as a result of anything you implement as a result of reading this post. I am also not responsible for incorrect math, ruining anyone’s weekend, or that long talk you now need to have with your boss about why your JSS is now broken.

One other thing to be aware of is that I’m going to be focusing on Linux and Windows in this post since those are the platforms that I’m most familiar with for hosting a Casper 9 JSS.

For more details, see below the jump:

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First look at Veertu

January 10, 2016 5 comments

One of the lesser-known changes that Apple introduced with OS X Yosemite was a Hypervisor framework, which was designed to allow virtualization solutions to be built for OS X without the need for third-party kernel extensions.

Screen Shot 2016 01 08 at 11 58 50 PM

One reason for this was that eliminating the need for kernel extensions allowed the possibility of virtualization software to be distributed and sold via the Mac App Store. While neither VMware or Parallels have taken advantage of this, a new virtualization product named Veertu has recently become available in the MAS.

Screen Shot 2016 01 08 at 8 13 38 AM

Veertu is available for free from the MAS, and allows installation of selected Linux VMs, downloaded from Veertu’s online library. For more details, see below the jump.

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Status report script for Linux-hosted Casper servers

December 14, 2015 1 comment

As part of keeping an eye on my support systems, I’ve been using a script for my Casper servers running on Linux which emails me a status report on a daily basis. I adapted this script from an earlier one I wrote to monitor Tomcat and alert me if Tomcat was having issues. The script tells me a number of things that are useful to know, including the following:

  • Uptime
  • Free space on all attached drives
  • Who’s logged in via SSH or in the console
  • Virtual memory statistics
  • Current system tasks
  • SMB connections information
  • Recent entries in the Apache server logs
  • Recent entries in the JSS server log

In my case, my Casper servers are hosted on Red Hat Enterprise Linux so I’ve focused this script’s development and testing on compatibility with RHEL-based Linux distributions. That said, nothing in it is RHEL-specific so it should also work on other Linux distributions. For more information, see below the jump.

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Categories: Casper, JSS, Linux, Scripting
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