When Running Oracle VirtualBox on a Windows Host with a Linux Guest, What Does the Linux Guest Think Is the IP Address of the Host?

Problem scenario:  You have Oracle VirtualBox installed on a Windows host.  You have Linux CentOS as a guest VM. You want to test network connectivity (e.g., hostname resolution).  You want to know what IP address the Linux guest could use to interact with the Windows host.

Solution
Install traceroute with this command:

sudo yum -y install traceroute

Then use this command:

traceroute 8.8.8.8

The results of the above traceroute command will show you the packet hop from the Linux guest to the Windows host. 

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How Do You Install Docker on an AWS Instance of RHEL?

UPDATE: If you are using RHEL 8.x use these directions instead of the ones below.

Problem scenario
You want to install Docker on an AWS instance of RedHat Linux.  You do not want to use CentOS packages.  What do you do?

Solution
For RedHat Linux running via AWS, you have to run one command to enable numerous yum repositories. 

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How Do You Configure Updates for a RedHat Server Running on AWS?

Question:  How Do You Get Yum Repositories to Work with a AWS Instance of RHEL?
Problem scenario:   You are using RedHat Linux via AWS and very few yum commands work.  The repositories are very limited, and few packages are available.  When trying to use yum to install packages, you see output like this:

“Loaded plugins: amazon-id, rhui-lb

No package lynx available.

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How Do You Troubleshoot Yum Commands Not Working with the Error “Could Not Resolve Host: mirror.centos.org Unknown Error”?

Problem scenario:  Yum commands to install packages are not working.  When you use “yum install coolpackage” you get an error like this:


http://mirror.centos.org/altarch/7/os/i386/repodata/repomd.xml: [Errno 14] curl#6 – “Could not resolve host: mirror.centos.org; Unknown error”
Trying other mirror.
https://yum.dockerproject.org/repo/main/centos/7/repodata/repomd.xml: [Errno 14] curl#6 – “Could not resolve host: yum.dockerproject.org; Unknown error”
Trying other mirror.


 One of the configured repositories failed (Docker Repository),

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When Did Automation Become an Important Concept to Businesses?

Question
When did automation become a division or a department in a business?  When did the term automation start to be used regularly?

Answer
A competitive market will push companies to be competitive.  With the conclusion of World War 2, America transitioned to a peace time economy.  Detroit stopped producing large numbers of tanks and started producing large numbers of cars.  1947 was the year Ford created its automation department (www.assemblymag.com). 

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How Do You Install Kubernetes on an AWS Instance of RedHat Linux?

Problem scenario:  You are using RHEL 7.x via AWS.  You want to install Kubernetes.  What do you do?

Solution
1.  Log into the Linux server as ec2-user.  Then run this command:
sudo yum-config-manager –enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional

2.  Create this file: /etc/yum.repos.d/kubernetes.repo
3.  Have this be the content of the file (with the first line being “[kubernetes]” and the last line ending in “…

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How Do You Deploy a Kubernetes Cluster in AWS Using an Ubuntu Linux Instance?

Updated on 12/2/18.

Problem scenario
You want to deploy a Kubernetes cluster in AWS.  You have an Ubuntu server (e.g., with a nano flavor in AWS or a minimally powered Azure instance).  It has no software packages installed on it (e.g., it does not have Docker or Kubernetes).  How do you deploy Kubernetes in AWS?

Solution
Warning:  This will automatically create EC2 servers in you AWS account behind the scenes. 

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How Do You Compile a C++ Program When You Get “Gcc: Error Trying to Exec ‘cc1plus’: Execvp: No Such File or Directory”?

Problem scenario:  When trying to compile a C++ program (e.g., $ gcc hello.cpp), you receive this error:
“gcc: error trying to exec ‘cc1plus’: execvp: No such file or directory”

What do you do?

Solution
Install gcc-c++.  For a RedHat distribution of Linux, use this command:

yum -y install gcc-c++

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How Do You Enable Virtualization Technology (VTx) with an HP Probook?

Problem scenario:  You want to use Oracle VirtualBox or some other hosted hypervisor with your HP Probook laptop.  You need “Virtualization Technology (VTx)” enabled.  How do you do this?

Solution

1.  Boot up.  When you see the “HP” splash screen (a blue image with a black background), press F10.

2.  At the prompt, “Log in as a Guest User” choose “Yes.” (This step may be crucial to your success.)

3.

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How Do You Write a C Program to Writes Hexadecimal Numbers 1 Through F Each on New Lines of a New File?

Problem scenario:  Using the C programming language, you want to write a program that produces a file (we’ll call it contint.txt) that has the following content:

1
2
3
4
5
6
7
8
9
a
b
c
d
e
f

Solution
Overview of the approach:  Hexadecimal numbers use base 16. 

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