A Technical I.T./DevOps Blog
Problem scenario
Some s3cmd commands work fine. But others give you this error:
“ERROR: S3 error: 400 (InvalidRequest): The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256.”
What can you do to get s3cmd commands to work consistently?
Solution
Upgrade your s3cmd to a newer version.
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Problem scenario
On a Windows server in AWS, you are trying to download a file with Internet Explorer. You get this error: “Your current security settings do not allow this file to be downloaded.” How do you solve this problem?
Solution
Using Internet Explorer 11, go to Internet Options. Go to the Security tab. Click on “Internet.” Scroll down to “Downloads.” For “File download” (beneath “Downloads”), choose “Enable.” Click “Ok” twice.
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Problem scenario
You want to install Maven with a script. You want the script to work regardless of what distribution of Linux you are using (e.g., Ubuntu/Debian, RedHat (including CentOS/Fedora), or SUSE). How do you write a script to install the latest version of Maven?
Solution
Update: This script was updated on 9/23/19.
1. Create this file in /tmp/ and call it maven.sh. Below is the content:
#!/bin/bash
# Written by www.continualintegration.com
mvnversion=3.6.2 # Change this version as necessary
distro=$(cat /etc/*-release | grep NAME)
debflag=$(echo $distro | grep -i “ubuntu”)
if [ -z “$debflag” ]
then # If it is not Ubuntu, …
Continue reading “How Do You Install Maven on Any Type of Linux?”
Problem scenario
You want a Bash script to install Java on Linux. (If you want to install Java on Windows, see this posting.) You want it to work regardless if it is a Linux that is part of the Debian/Ubuntu family, RedHat family (e.g., CentOS/Fedora), or SUSE. What do you do to write a universal script to make it easy for other systems administrators to install Java (or potentially automate the process across several servers)?
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Continue reading “How Do You Install Java on Any Type of Linux with a Script?”
Question
What are the different acronym stacks in I.T.?
Answer
There are many open source combinations of technologies that are in wide use. These acronyms referred to as “full stacks” or “stacks” appear in articles and job descriptions. A full stack is a bundle of software that (includes an OS and) can create a complete and functional product when properly configured.
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Continue reading “What Are the Different Acronym Stacks in I.T.?”
Problem scenario
Recently you deployed Kubernetes to AWS using JuJu. You are now eliminating the Security Groups that it created. You cannot delete a Security Group in AWS. You get an error about the Security Group being associated with one or more network interfaces. You cannot detach the network interface. You even click the “Force detachment” and then click “Yes, Detach.” Nothing works to delete the network interface or remove the Security Group.
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Problem scenario
You want to know what version of MariaDB is installed on your Linux server. You do not have credentials to log into the SQL prompt. What OS command can you run to determine the version of MariaDB?
Solution
Run this command:
mysql -h localhost -V
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Continue reading “How Do You Find the Version of MariaDB That Is Installed on Your Linux Server?”
Problem scenario
You want to install Splunk Enterprise on your RedHat Enterprise Linux server. How do you do this?
Solution
You can get a free trial here if you input the data the Splunk company requires and can agree to the terms that they have. Use an SFTP client (e.g., WinSCP) to move it to your server.
From the Linux server run this: sudo yum -y localinstall splunk-*
Run this command: sudo /opt/splunk/bin/splunk version
Read the License Agreement.
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Continue reading “How Do You Install Splunk Enterprise on a RHEL Server?”
Updated on 1/6/21
Problem scenario
You want to install open source Hadoop. You may want a single-node or multi-node deployment with CentOS/RedHat/Fedora, Debian/Ubuntu, and/or SUSE Linux distributions. You want to have most of it scripted and have the same script work on any variety of Linux. How do you install Hadoop quickly with a script that works on almost any type of Linux?
Solution
1.
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Continue reading “How Do You Install Hadoop with a Script for Any Type of Linux Server?”
Problem scenario
You want to list the instrumented JVMs on your Linux OS. Therefore you want to run the command jps. What package(s) do you need to install?
Solution
For CentOS/RedHat/Fedora run this:
sudo yum -y install java-1.8.0-openjdk-devel
For Linux SUSE run this:
sudo zypper -n install java-1_8_0-openjdk-devel
For Ubuntu/Debian Linux run this:
sudo apt-get -y install openjdk-8-jdk-headless default-jre
If you want to learn more about the Java process status tool,
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