A Technical I.T./DevOps Blog
Question
What Is an ARM in Modern Information Technology Vernacular?
Answer / Disambiguation
In I.T. jargon the term ARM can refer to a number of different things. Here are some potential definitions of this acronym in random order:
#1 Azure Resource Manager is a component of Azure. It can be interacted with in the console if you log into a Azure via a web browser.
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Continue reading “What Is an ARM in Modern Information Technology Vernacular?”
Problem scenario
You are trying to create a Linux server in Azure with the Azure Tools for PowerShell. You receive this message:
“Destination path for SSH public keys is currently limited to its default value due to a known issue in Linux provisioning agent.”
You see “StatusCode: 400 … ReasonPhrase: Bad Request.”
What do you do to create an Ubuntu 16.x server and not get this error?
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Problem scenario
You want to configure the LAMP stack (Linux, Apache web server, MySQL/MariaDB, and PHP) on a running a RedHat distribution of Linux. How do you do this?
Solution
Run this command:
sudo yum -y install php httpd mariadb-server
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Continue reading “How Do You Deploy LAMP to a RedHat/CentOS/Fedora Server?”
Problem scenario
You are trying to start HDFS. But you get this error: “WARN conf.Configuration: bad conf file: element not <property>”
What should you do?
Solution
Look at mapred-site.xml, hdfs-site.xml, and core-site.xml files. Verify you have a <property> tag in each file.
cat /path/to/mapred-site.xml | grep -i property
cat /path/to/hdfs-site.xml | grep -i property
cat /path/to/core-site.xml | grep -i property
If there is no <property>
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Problem scenario
Your enterprise’s policies are to install a version of Jenkins that is lower than the latest. How do you install Jenkins 1.651.1 on Ubuntu 16.04?
Solution
1. Install Java. See this posting if you do not know how.
2. Run these three commands to install Jenkins 1.651.1 (but you can chance the version whichever one is available):
curl -L https://pkg.jenkins.io/debian-stable/binary/jenkins_1.651.1_all.deb /tmp/jenkins_1.651.1_all.deb
sudo apt-get -y install daemon
sudo dpkg -i /tmp/jenkins_1.651.1_all.deb
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Continue reading “How Do You Install an Older Version of Jenkins (e.g., 1.x) on Ubuntu Linux?”
Problem scenario
You are using a RedHat derivative distribution of Linux (e.g., CentOS/RHEL/Fedora). To eliminate a Hadoop error, you need to install a variety of packages. How do you install Maven, openjdk, libssl-Dev, build-Essential, and pkgconf?
Solution
To install Maven, see this article.
For the rest of the packages, run these commands:
sudo yum -y install java-1.8.0-openjdk-devel openssl-devel cmake protobuf
sudo yum -y groupinstall ‘Development Tools’
curl ftp://rpmfind.net/linux/fedora/linux/updates/25/x86_64/p/pkgconf-1.3.7-1.fc25.x86_64.rpm pkgconf-1.3.7-1.fc25.x86_64.rpm
curl ftp://rpmfind.net/linux/fedora/linux/updates/25/x86_64/l/libpkgconf-1.3.7-1.fc25.x86_64.rpm libpkgconf-1.3.7-1.fc25.x86_64.rpm
sudo rpm -ivh *.rpm …
Problem scenario
You want to know how to discuss Microsoft’s public cloud offering. You do not know how to pronounce “Azure.” How should it be pronounced?
Solution
It is pronounced “azh-er” according to Dictionary.com. To hear it pronounced you can click on the link above. Another related video is here.
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Problem scenario
You set up Chef server and Chef client on Linux servers. On the Chef client server you run this command:
knife client list
You get this as the output:
ERROR: The object you are looking for could not be found
Response: <!DOCTYPE html>
<html xmlns=”http://www.w3.org/1999/xhtml”>
<head>
<meta http-equiv=”Content-Type” content=”text/html; charset=utf-8″ />
<meta http-equiv=”X-UA-Compatible” content=”IE=EmulateIE7″ />
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Problem scenarios
This is a two-in-one posting. The same solution works for two different problem scenarios.
Problem scenario A
You want to create a certificate signing request permissions file (a csr.pem) to learn more about it. You also want to try to use HTTPS as a test. How do you do these things?
Problem scenario B
You want to implement a solution with TLS.
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Problem scenario
You have installed Chef server on a RedHat Enterprise Linux (RHEL) server in AWS. You have installed Chef client on another RHEL instance in AWS. You simply want your Chef client to receive configuration management changes (e.g., you want Chef recipes to work). The command “chef node list” on your Chef client server returns no servers. You ran this command from the Chef client:
sudo chef-client -S https://<FQDN of Chef server>/organization/contint
But you received an error like this:
Chef encountered an error attempting to create the client “<FQDN of Chef Client computer>”
================================================================================
System Info:
————
chef_version=13.4.19
ruby=ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]
program_name=chef-client worker: ppid=5156;start=14:10:31;
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