Category Archives: Uncategorized

How To Enable Root On Mac

A full blog post with all the steps listed out can be found here. Macs are built on Unix and as such, you can use the terminal to run commands. However, by default root is disabled. This video will show you how to enable root on mac so you can run commands as sudo.

  • Click the apple symbol the upper left of your screen.
  • Click System Preferences
  • In the screen that appears click Users and Groups.
  • Click login options and then click the lock to allow you to make changes.
  • In the screen that appears enter your username and password.
  • Click Join next to Network account Server.
  • Then click Open Directory Utility.
  • In the screen that appears click the lock to allow you to make changes.
  • Enter your username and password.
  • Now at the top of the screen click edit & then Enable Root User.
  • Enter your root password and then click ok.
  • You can now run commands as root from the Mac Terminal

A full video can be found here:

 

AWS User Data | How to run commands on startup Amazon Linux

Userdata on AWS allows you to run commands on start-up when you launch an EC2 instance on AWS. This is known as boot strapping your instance. In this example we will be boot strapping Amazon Linux with the Apache web server.

Step 1

First log into you AWS portal and then click services and EC2

Step 2

Next Click launch instance.

Step 3

Select Amazon Linux

Step 4

Leave the instance as mirco to get the free tier and click next Configure instance details

Step 5

Leave the defaults and scroll down to advanced details and expand it – enter the following lines into the textbox:

#!/bin/bash
yum install httpd -y
systemctl start httpd
systemctl stop firewalld
cd /var/www/html
echo "this is my test site" > index.html

The text in the code block above installs apache and adds an simple webpage that reads this is my test site. Finally click Next add storage

Step 6

Leave the defaults and click next add tags

Step 7

Give your machine a name and click Next Configure Security Group.

Step 8

Allow port 80 from 0.0.0.0/0 on the security group and click review and launch

Step 9

Click Launch

Step 10

You can proceed without a keypair as we will not log into this instance

Step 11

click your instance ID

Step 12

Wait until your instance is running and then copy it’s pubic IP or dns name

Step 13

Open a new browser and enter the pubic IP of your Linux instance into the address bar. You should now see the simple webpage we created.

A full video tutorial can be found here:

How to set up HTTPS on Tomcat

Apache Tomcat, often referred to as Tomcat Server, is an open-source Java Servlet Container developed by the Apache Software Foundation (ASF). Tomcat implements several Java EE specifications including Java Servlet, JavaServer Pages (JSP), Java EL, and WebSocket, and provides a “pure Java” HTTP web server environment in which Java code can run.

This Tomcat Tutorial will show you how to create a self signed cert that you can then use to secure Tomcat.

Step 1

Open a command prompt window and navigate to your JAVA_HOME bin folder, in our case:

C:\Program Files\Java\jre1.8.0_171\bin

Step 2

Enter the command:

keytool -genkey -alias tomcat -keyalg RSA -keystore “C:\apache-tomcat-8.5.34\conf\localhost.jks”

Note: You should update the tomcat path to match your path 

Step 3

You will then be prompted for a series of values, in our case we entered:

enter Keystore password: password
retype keystore password: password
what is your first and last name: localhost
what is the name of your orgainsation unit: IT
what is the name of your organisation: Darren
what is the name of your city: Dublin
what is the name of your state or province: Leinster
What is the two-letter country code for this unit: IE

When prompted type yes to confirm all is correct.

Next you will be asked to use the same password for <tomcat>, press enter here:

Step 4

Now open the tomcat server.xml file, in our case the file is located here:

C:\apache-tomcat-8.5.34\conf\server.xml

Step 5

Add the following block to the file:

	<Connector
		protocol="HTTP/1.1"
		port="8443" maxThreads="200"
		scheme="https" secure="true" SSLEnabled="true"
		keystoreFile="conf\localhost.jks" keystorePass="password"
		clinetAuth="false" sslProtocol="TLS" />

Step 6

Restart Tomcat.

Step 7

Navigate to https://localhost:8443.

You should first see a certificate warning, click to bypass the warning.

Step 8

You should now see Tomcat working over HTTPS

A full video tutorial can be found here:

How to install IIS on server 2016

Internet Information Services (IIS, formerly Internet Information Server) is an extensible web server created by Microsoft for use with the Windows NT family.[2] IIS supports HTTP, HTTP/2, HTTPS, FTP, FTPS, SMTP and NNTP. It has been an integral part of the Windows NT family since Windows NT 4.0, though it may be absent from some editions (e.g. Windows XP Home edition), and is not active by default.

This IIS web server tutorial will show you how to install IIS 10 on Windows server 2016.

step 1

Click on the start menu and then server manager

Step 2

Next click on manage and then add Roles and Features.

Step 3

Click Next

Step 4

Click Next again.

Step 5

Click next one last time.

Step 6

Scroll down and click Web Server (IIS)

Step 7

In the screen that appears click Add Features.

Step 8

Click Next.

Step 9

Click Next

Step 10

Click Next again.

Step 11

Leave the default and click next.

Step 12

Click install

You should now see a message saying Install successful. Click close to exit the installer.

A full video tutorial can be found here:

 

How to install VirtualBox on Windows Server 2016 / Windows 10

“Oracle VM VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and Innotek VirtualBox) is a free and open-source hypervisor for x86 computers currently being developed by Oracle Corporation. Developed initially by Innotek GmbH, it was acquired by Sun Microsystems in 2008 which was in turn acquired by Oracle in 2010.”

In this tutorial you will see how to install VirtualBox on Windows Server 2016. The process for the install will be the same for windows 1o.

Step 1

Go to https://www.virtualbox.org/wiki/Downloads and click windows hosts:

Step 2

When the download has completed go to your downloads folder and double click the VirtualBox installer :

Step 3

Click next

Step 4

Click next again

Step 5

Click Next again

Step 6

Note that your network card will briefly go off and on again, if you are happy to proceed click next

Step 7

Click install.

Step 8

Click Finish.

A full video guide can be found here:

VirtualBox host only adaptor disappeared (Interface (‘VirtualBox Host-Only Ethernet Adapter’) is not a Host-Only Adapter interface (VERR_INTERNAL_ERROR) SOLVED

Hi there,

After recently updating Windows 10, none of my VMs in VirtualBox would power on. I kept receiving an error that read:

(Interface (‘VirtualBox Host-Only Ethernet Adapter’) is not a Host-Only Adapter interface (VERR_INTERNAL_ERROR) SOLVED

 

After looking around the settings of my Windows 10 machine I noticed that the host only adaptor was missing. To fix it I added a new adaptor by doing the following:

Step 1

I clicked file and then Host Network Manager

Step 2

In the screen that appears I then clicked Create, to create a new Host Only Network.

Step 3

I then right clicked on the VM i wanted to start and clicked settings.

Step 4

I then did the following:

  • Clicked on Network.
  • Selected the checkbox to enable Network adaptor.
  • Assigned the Host only adaptor I created.
  • I then clicked ok.

The VM then booted without issue.

A full video Tutorial can be found here:

Linux Keyboard wrong

Subscribe to Darrenoneill.eu to get a free Linux Cheat Sheet! 

This is a tip which has got be out of a few binds before. So what happens is you are called to a job to troubleshoot a issue on a Linux server. You access the terminal and the keys you are typing are not appearing on the screen. For example, when you type @ you see ” and when you type # you see \.

This is happening because the terminal is expecting input from a US keyboard and you are using a UK keyboard.

You can solve this very quickly by typing the command:

sudo loadkeys uk

When this command is run successfully you should see a screen that looks like the one below.

Your keys should now be working correctly.

A video that shows this process can be found here:

 

How to Install Wildfly on windows

“WildFly  formerly known as JBoss AS, or simply JBoss, is an application server authored by JBoss, now developed by Red Hat. WildFly is written in Java and implements the Java Platform, Enterprise Edition (Java EE) specification. It runs on multiple platforms.”

In this tutorial we will be installing Wildfly on windows server 2016, however the process should be much the same on windows 10.

Installing Java

First we will download and install Java JRE. it is available from:

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

And we downloaded the windows 64 bit version.

Once it downloads install it.

Downloading WildFly

Go to http://wildfly.org/downloads and click to download the Java EE7 Full & Web Distribution

When it downloads unzip it to your C drive.

Running WildFly for the first time.

Navigate to C:\wildfly-12.0.0.Final\bin and run standalone.ps1 in PowerShell

When WildFly has started you should see a screen similar to the below:

Now open a browser and navigate to http://localhost:8080 you should see the WildFly welcome screen:

 

  • Next minimise your browser and navigate back to  C:\wildfly-12.0.0.Final\bin.
  • Run add-user.ps1 with PowerShell by right clicking and selecting run with PowerShell

 

Add a management user by pressing enter at the below screen (it is the default option)

  • Enter the details of your user.
  • when asked “What groups do you want this user to belong to?” press enter
  • and then type yes to add the user for the realm ManagemntRealm

  • When asked; “Is this new user going to be used for one AS process to connect to another AS process?” type no
  • Return to the PowerShell window that has WildFly running and press ctrl+c to kill the process, the PowerShell window should close.
  • open a bowser and navigate to
    • http://localhost:9990
  • You will be promoted to log in, enter the username and password that you set and click ok.

  • You should now see the management console.

 

  • Minimise your browser and navigate back to the PowerShell window and stop wildly by running ctrl + c

Installing WildFly as a service.

  • navigate to C:\wildfly-12.0.0.Final\docs\contrib\scripts\
  • Copy the service directory to C:\wildfly-12.0.0.Final\bin

  • open up and admin CMD and navigate into C:\wildfly-12.0.0.Final\bin\service

Next run “service.bat install”

Next open windows Services, you should see WilDfly installed, you can now start it from here and set it to automatic.

a full video tutorial can be found here:

How to set up Crontab on CentOs7 Linux

This short video will show you how to set up cron jobs on CentOS 7.

Although the Linux distro in the tutorial is CentOS 7, this tutorial should work on most versions of Linux.

We first set up a script that will allow us to test cron.

We then enter cron by running crontab -e.

We then tell cron to run the script every minute of everyday to see if output is generated.

The cron test script that we use is called crontest.sh. It contains the following lines:

#!/bin/bash
today=$(date)
touch /home/scripts/"$today"

The crontab examples that we use in the video are:

* * * * * /home/darren/scripts/crontest.sh #runs every minute
*/5 * * * * /home/darren/scripts/crontest.sh #runs every minute
0 * * * *  /home/darren/scripts/crontest.sh #runs every hour
0 0 * * * /home/darrenscripts/crontest.sh #runs every day

And the Cron website that was shown in the tutorial can be found here:

https://crontab.guru 

If you encouter any difficulty while following along to this tutorial please do comment below 🙂

How To Delete Pages From a PDF without adobe acrobat (free)

This video tutorial shows you how to delete pages from a PDF for free.

 

Software such as adobe reader does not allow you to delete pages from PDF documents.

 

Software such as Adobe Acrobat is expensive.

 

In this tutorial we use PDF Edit which is a freeware program.

 

The link for the PDF edit software used in this tutorial is:

 

https://sourceforge.net/projects/pdfedit/

 

This tutorial first shows you how and where to download the pdf edit software for free.

 

Next it will show you how to install the pdf edit software.

 

It will then show you how to open a pdf in pdf edit.

 

It will then show you how to remove / delete pages from a pdf.

 

After deleting pages from your pdf you will then see how to save your new pdf.