Category: Linux

Convert OVFs to an OVA without the ovftool.exe

VMware requires you to have an account to logon and download a free tool called “VMware OVF Tool”.  That alone is not annoying.  What is annoying is that the tool is extremely slow.  There is a much faster way to create an OVA without the need of this tool. Using the ovftool is easy enough, the following is an example…

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NFL Pick ‘Em buildSchedule.php for any season

I have been playing around with the buildSchedule.php component of NFL PHP Pick ‘Em as this is the component that makes it all possible to generate tables needed to create the SQL script to import into the new season.  My previous post on this subject required a spreadsheet, which never really was necessary.  Even though the output filename contains a…

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NFL Pick ‘Em for 2019 Season

NFL PHP Pick ‘Em is a free php web app that allows you to host a weekly NFL pick ’em football pool on your website.  This fantastic tool replaced the use of spreadsheets.  There was a time that this tool was not supported.  However, I just checked out the www.phpickem.org website it is is updated for 2019. I wish I…

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Automatically clean /tmp or /var/tmp files that are in protected PrivateTmp directories in CentOS / RHEL 7

With CentOS/RHEL 6 there was a function called tmpwatch that was launched /etc/cron.daily/tmpwach This process has changed in CentOS/RHEL 7. There is a system target that runs daily: system-tempfiles-clean.timer. Although tmpwatch does a pretty good job in cleaning out the /tmp or /var/tmp files, it does not by default clean out the /tmp/systemd-private directories as these are secure.  There are…

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Install CentOS 7 on a GPT labeled disk

For one reason or another it was difficult to find the “complete” answer to installing CentOS 7 on a GPT labeled disk.  For the most part the answer was too complicated, incomplete, or inaccurate. After some trial and error the answer turns out to be a simple one. Process This was an example of a very basic install only to…

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Extend the swap logical volume size

Extend the swap size in a logical volume may be needed.  Assume that there is a swap partition that requires an additional 1G of space.  The following process should work on a CentOS 7 Linux install. Assuming that the disk space is available, use lvextend will add 1G, disable and flush out the existing swap space.  It may take some…

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Root Login Permission Denied on CentOS7

A system that was a fresh installation of CentOS 7 Linux was just completed. After all the updates, the user began to install an application. After some time, the user logged out of the system and could not log back into it. As a root user, the administrator was unable to access the virtual machine even via console. This eliminated…

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Disk Full Error: Cannot logon via SSH

The issue is that there may be a policy in place to prevent logons if there is any mount that is full.  There are a couple of approaches towards resolution.  Both approaches require a system shutdown.  One approach requires access to the ISO, which leaves a plausible solution. reboot Hit CTL+X to edit the boot kernel ##CHECK THIS ONE, MIGHT…

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SELinux: Compile a policy package

You have generated a SELinux human readable .te file and want to compile it into a .pp policy file. Prerequisites Only needed for sealert yum install setroubleshoot-server Troubleshooting This is a series of commands used to troubleshoot a recent zabbix-server service that would not start. It was the results of the ausearch that revealed the semodule command that differed from…

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Apache Tomcat 9 – SSL/TLS Configuration HOW-TO

In this exercise, Tomcat 9 will be installed with OpenJDK 8 using a self-signed certificate in a PKS12 keystore on a clean CentOS 7 Linux server using the Http11NioProtocol protocol.  These are the steps. Enjoy Tomcat Check the Cert You can check the cert by using your browser. http2.Http2Protocol Alternately, you can use the http2.Http2Protocol protocol.  However, there is one prerequisite…

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Install Elastic Stack 5.6 on CentOS 7

By combining the massively popular Elasticsearch, Logstash, and Kibana (what was the ELK Stack is now the Elastic Stack), Elastic has created an end-to-end stack that delivers actionable insights in real time from almost any type of structured and unstructured data source. There are many resources that offer installation procedures from simple to complex configurations. This is my take on…

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Migrate User Accounts from one CentOS server to another CentOS server

There are many articles that suggest that simply copying certain files from one CentOS to another CentOS server will be sufficient enough to migrate the user accounts along with their permissions and passwords.  Other arguments suggest that certain files such as the passwd and shadow files should never be manually edited; but the caveat is that there is no “utility”…

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Automate the kinit process with a secure password

If in the event you want to automate the kinit process and automate this process at logon, the steps outlined below will work.  This has been tested on a CentOS 7 installation. ktutil ktutil: addent -password -p username@DOMAIN.COM -k 1 -e rc4-hmac Password for username@DOMAIN.COM: [enter your password] ktutil: addent -password -p username@DOMAIN.COM -k 1 -e aes256-cts Password for username@DOMAIN.COM:…

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Atlassian JIRA support for unsupported OpenJDK

Atlassian JIRA does not support OpenJDK. Oracle has changed it licensing for Oracle JDK.  With that in mind, the goal is to use OpenJDK as a replacement for the Oracle JDK. This is possible and easy to do. Search for your jira install %JIRA_HOME/jira/bin/check-java.sh.  On the line that contains “java version” change it to “openjdk version“, then restart your install…

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pihole becomes unresponsive

If pihole becomes unresponsive, one reason may be that the diskspace is full. The diskspace may become full from an excessively large pihole database and or /var/log entries.  In a recent case, both were the cause.  Stopping the services and truncating the logs in /var/log and deleting the database worked in this case.  The following logs were large, but I…

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pihole reset all stats

There may be a time where you want to have a fresh dashboard without the stats and logs.  A case maybe a misconfigured NIC that may dump millions of DNS queries into the logs.  Yup I have seen this happen. Whenever you need to reset the pihole stats and logs that display on the /admin dashboard, the following options will…

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Create systemd services for Atlassian Apps

While working with the Atlassian products over the years, a pattern emerges. Even though there are distinct differences in their setup and configurations, the installation process can be generalized. One of the post-installation considerations to make is in the manual creation of a service.  The benefit of a service is that it will automate the running of the application, rather…

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