Category Archives: Linux

How to install NodeJS on a Raspberry Pi

Installing NodeJS on a Raspberry Pi can be a bit tricky.  Over the years, the ARM based processor has gone through several versions (ARMv6, ARMv7, and ARMv8), in which there are different flavors of NodeJS to each of these architectures.

Depending on the version you have, you will need to manually install NodeJS vs grabbing the packages via a traditional apt-get install nodejs.

Step 1: Validate what version of the ARM chipset you have

First let’s find out what ARM version you have for your Raspberry Pi.  To do that, execute the following command:

uname -m

You should receive something like: armv61

Step 2: Find the latest package to download from nodeJS’s website

Navigate to https://nodejs.org/en/download/ and scroll down to the latest Linux Binaries for ARM that match your instance.  Right click and copy the address to the instance that matches your processor’s architecture.  For example, if you saw armv61, you’d copy the download for ARMv6

Step 3: Download and install nodeJS

Within your SSH/console session on the Raspberry Pi, change to your local home directory and execute the following command (substituting in the URL you copied in the previous step in what’s outlined in red below).  For example:

cd ~
wget https://nodejs.org/dist/v8.11.3/node-v8.11.3-linux-armv6l.tar.xz

Next, extract the tarball (substituting in the name of the tarball you downloaded in the previous step) and change the directory to the extracted files

tar -xvf node-v8.11.3-linux-armv6l.tar.xz
cd node-v8.11.3-linux-armv6l

Next, remove a few files that aren’t used and copy the files to /usr/local

rm CHANGELOG.md LICENSE README.md
cp -R * /usr/local/

Step 4: Validate the installation

You can validate that you have successfully installed NodeJS by running the following commands to return the version numbers for NodeJS and npm

node -v
npm -v

That’s it!  Have fun!

 

How to build a LEMP stack

Growing up it was always common to spin up a “LAMP” box to host a website.  The typical setup was:
Linux
Apache
MySQL
PHP

Over the past few years, this model has slightly changed due to new open source technologies bringing new ideas to solve performance and licensing issues at massive scale.  In this tutorial, we are going to look at setting up a LEMP box on Debian Stretch (9.1).
Linux
nginx [engine x]
MariaDB
PHP

Please note, MariaDB could easily be swapped out with MySQL in this tutorial, however many have opted to jump over to MariaDB as an open source alternative (actually designed by the original developers of MySQL) over fear Oracle may close source MySQL.

Installing Linux

This tutorial assumes you already have either a copy of Ubuntu 14+ or Debian 7+.  This probably works on earlier versions as well, but I haven’t tested them.  On a side note, I typically don’t install Linux builds with an interactive desktop environment, so grab yourself a copy of Putty and ssh in or open up Terminal if you have interactive access to the Desktop Environment.  Before continuing, go ahead and update apt-get repos and upgrade any packages currently installed:

apt-get update && apt-get upgrade

Installing nginx

Grab a copy of nginx

apt-get install nginx

Installing MariaDB

Grab a copy of MariaDB

apt-get install mariadb-server

Installing PHP

In this case, I want to roll with PHP7.  You can specify php5 or php7 depending on your application, but PHP7 has some great performance enhancements, so for new apps, I’d leverage it.  The biggest thing here is to make sure you use the FastCGI Process Manager package.  If you specify just php or php7, package manager will pull down apache2 as a dependency.  That is not what we want in our LEMP stack.

apt-get install php7.0-fpm

Once installed, fire up your favorite text editor (it’s ok if it’s vi :)) and edit the default site for nginx

vi /etc/nginx/sites-enabled/default

Search for the comment # Add index.php to the list if you are using PHP and add index.php to the line below it.  For example:

index index.html index.htm index.php index.nginx-debian.html;

Next, find the comment # pass PHP scripts to FastCGI server and change the block of code to the following to tell nginx to process .PHP files with FastCGI-PHP:

# pass PHP scripts to FastCGI server
#
location ~ \.php$ {
include snippets/fastcgi-php.conf;
#
# # With php-fpm (or other unix sockets):
fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
# # With php-cgi (or other tcp sockets):
# fastcgi_pass 127.0.0.1:9000;
}

Save the file.  If using vi, you can do that by executing :wq

Next, reload the nginx service to pickup the new changes to our configuration:

service nginx reload

Test

At this point, we can create a php file to validate things are working well. Go ahead and create a new file /var/www/html/info.php and add the following line:

<?php
phpinfo();

If you see a page listing the PHP version and the corresponding environment configuration, congratulations, you have finished setting up your new LEMP stack! 🙂

[Tutorial] Adding firewall rules via system-config-firewall-tui on CentOS 6

Here is a quick tutorial on how to add an ingress firewall rule on your CentOS 6 machine.  In this example, we will be forwarding port 443 for HTTPS.

  1. Open up terminal if you are on the GUI version of CentOS 6
    CentOS6 - Terminal
  2. Execute the following command
    1. system-config-firewall-tui
      Terminal - system-config-firewall-tui
  3. Use your arrow keys to select Customize and hit enter
    system-config-firewall-tui - Customize Rules
  4. Use your arrow keys to select which service you would like to allow.  Hit the spacebar to enable or disable the rule and then select Close once you have enabled/disabled the rules you wish.
    1. In this case, I arrowed down to HTTPS and hit the spacebar.
      system-config-firewall-tui - Select Rules
  5. Select OK
    system-config-firewall-tui - Apply Rules
  6. Select Yes
    system-config-firewall-tui - Apply Rules - Confirmation

[Tutorial] How-to install VMTools on CentOS 6

Here is a quick tutorial on how to get VMware Tools up and running on a CentOS 6 Linux machine.  Although the instructions are shown with the GUI, we’ll use terminal so the guide works with both gui and non-gui based installs.

  1. Mount the VM tools installer to your VM
    Install-Upgrade VMware Tools
  2. Open up Terminal
    CentOS6 - Terminal
  3. Execute the following command (this will create a mount point for our CD drive)
    1. mkdir /cdrom
      CentOS6 - VMware Tools - New Mount Point
  4. Execute the following command (this will map the CD drive to our cdrom mount point)
    1. mount /dev/cdrom /cdrom
      CentOS6 - VMware Tools - Map Mount Point cdrom
  5. Execute the following command to move to your temporary files folder
    1. cd /tmp
      CentOS6 - VMware Tools - Temporary Files
  6. Execute the following command to extract the VMware Tools tarball
    1. tar -xvf /cdrom/VMwareTools (tab to autofill the rest of the package)
      CentOS6 - VMware Tools - Extract VMware Tools
  7. Execute the following command to run the VMware Tools installer
    1.  ./vmware-tools-distrib/vmware-install.pl
      CentOS6 - VMware Tools - Install VMware Tools
  8. Press Enter/Return through each of the questions, using their defaults
    CentOS6 - VMware Tools - Install Default Values
    CentOS6 - VMware Tools - Install Default Values Continued
    CentOS6 - VMware Tools - Install Default Values Continued Continued
  9. Verify VMtools is running by looking at the client status in vSphere
    CentOS6 - VMware Tools - vSphere Status

Set static IP on CentOS 6 via command line

Here is how to configure a static IP on CentOS 6 via command line.

  1. Determine which interface you want to configure–in this example, I will be using eth0
    1. ifconfig -a
    2. Show all linux interfaces
  2. Edit the interface you wish to configure (I’ll use nano as vi requires some knowledge for beginner Linux users)
    1. nano /etc/sysconfig/network-scripts/ifcfg-eth0
    2. nano ifcfg-eth0
  3. Use the following settings and then use Control+O to Save and Control+X to Exit
    1. nano /etc/sysconfig/network-scripts/ifcfg-eth0
    2. DHCPCLASS=
      IPADDR=192.168.1.100
      NETMASK=255.255.255.0
      ONBOOT=yes
      BOOTPROTO=STATIC
    3. static IP CentOS
  4. Next, let’s configure the hostname and default gateway.  We will use nano again to edit the file.
    1. nano /etc/sysconfig/network
    2. Ensure GATEWAY=192.168.1.1 has been set
    3. Static Gateway
  5. Next, let’s configure our DNS servers to resolve domain names (in this case, I will set mine to use Google’s DNS servers)
    1. nano /etc/resolv.conf
    2. nameserver 8.8.8.8
      nameserver 8.8.4.4
    3. static nameservers
  6. Restart the networking service for the changes to take effect
    1. /etc/init.d/network restart
    2. restart interface

sh: /usr/bin/vmware-config-tools.pl: Permission denied VMware Tools Linux

Symptom: You see the following permissions error when trying to install VMware Tools on a Linux OS regardless if you are running as su or root:

[[email protected] vmware-tools-distrib]# ./vmware-install.pl
Creating a new VMware Tools installer database using the tar4 format.

Installing VMware Tools.

In which directory do you want to install the binary files?
[/usr/bin]

What is the directory that contains the init directories (rc0.d/ to rc6.d/)?
[/etc/rc.d]

What is the directory that contains the init scripts?
[/etc/rc.d/init.d]

In which directory do you want to install the daemon files?
[/usr/sbin]

In which directory do you want to install the library files?
[/usr/lib/vmware-tools]

The path “/usr/lib/vmware-tools” does not exist currently. This program is
going to create it, including needed parent directories. Is this what you want?
[yes]

In which directory do you want to install the documentation files?
[/usr/share/doc/vmware-tools]
The path “/usr/share/doc/vmware-tools” does not exist currently. This program
is going to create it, including needed parent directories. Is this what you
want? [yes]

The installation of VMware Tools 9.0.5 build-1137270 for Linux completed
successfully. You can decide to remove this software from your system at any
time by invoking the following command: “/usr/bin/vmware-uninstall-tools.pl”.

Can’t exec “/usr/lib/vmware-tools/bin/configure-gtk.sh”: Permission denied at ./vmware-install.pl line 3955.
Before running VMware Tools for the first time, you need to configure it by
invoking the following command: “/usr/bin/vmware-config-tools.pl”. Do you want
this program to invoke the command for you now? [yes]

sh: /usr/bin/vmware-config-tools.pl: Permission denied
/sbin/restorecon:  Warning no default label for /tmp/vmware-block-restore0/tmp_file
[[email protected] vmware-tools-distrib]#

CentOS VMware Tools Permission Error

Solution: You need to extract the files from the tarball when installing the guest tools via the tar command rather than the build in Archive Manager installed with the OS.

  1. Mount the VMware Tools to the VM
  2. Copy the VMware Tools tarball to the desktop of the Linux OS
    Copy VMwareTools
  3. Execute the following command to extract the tar’s contents
    1. tar -zxvf VMwareTools-9.0.5-1137270.tar.gz
  4. Change directories to the vmware-tools-distrib that was just extracted from the tarball and execute the following commands to begin the installation
    1. cd vmware-tools-distrib
    2. ./vmware-install.pl
      vmware-install.pl

Setting up Java Runtime Environment 7 (JRE7) on Ubuntu 12.04 via Command Line

Need Java to run an application on your Linux workstation/server?  Follow the steps below via the terminal to install the latest version of Java.

  1. Head over to http://www.java.com/en/download/manual.jsp to find the latest Linux download from your client machine.
  2. Look at the link for the latest Java release for Linux.  Since we are using Ubuntu we do not need the RPM release.  In this case, I will be downloading Java 1.7.0_25-b15 for Linux x64.
    1. The download url is http://javadl.sun.com/webapps/download/AutoDL?BundleId=78697
  3. Head over to the Linux terminal on the machine you want to install Java on, and execute the following command to download the files from Java’s website
    1. wget http://javadl.sun.com/webapps/download/AutoDL?BundleId=78697
  4. Extract the tarball.  Since wget cannot pull the filename like a modern webrbowser, you will have to reference the weird filename AutoDL?BundleId=78697
    1. tar -xvzf AutoDL?BundleId=78697
  5. Find out what the name of the folder is of the java files you extracted by listing the files in the current directory.  At the time of writing this, the extracted folder I had was jre1.7.0_25, so I will continue to reference that moving forward.
    1. ls
  6. Create a folder in the usr folder for Java to reside.
    1. sudo mkdir /usr/java/
  7. Move the files we extracted Java files to the java folder
    1. sudo mv jre1.7.0_25/ /usr/java/
  8. Execute the following to enable the Java Runtime Environment
    1. sudo update-alternatives –install /usr/bin/java java /usr/java/jre1.7.0_25/bin/java 1
  9. Execute the following command to set the default Java to use
    1. sudo update-alternatives –config java
  10. Execute the following command to verify that the latest version of java is installed
    1. java -version
  11. Remove the tarball we downloaded from Java’s website to free up some space
    1. rm ~/AutoDL?BundleId=78697

Install Self-Signed CA Certificates on Ubuntu 12.04 via Command Line

Copy your .crt files to /usr/share/ca-certificates

Run: sudo update-ca-certificates

Hit yes to trust the certificates in the wizard (text based for CLI), and away you go! 🙂

How to enable and disable apache2 modules in Linux

a2enmod modulename – this will enable a module

a2dismod modulename – this will disable a module

 

Once you have made the changes, execute the service apache2 restart command and away you go!

How To Install VMWare Tools v4 on Ubuntu 12.04 LTS Server

Today I was faced the challenge of installing VMware Tools on a Ubuntu server via command line.  I stumbled accross a step-by-step tutorial on the exact steps to accomplish this task.  I am reposting for archival purposes, but all credit goes to @justinschier from http://ghosttx.com/2012/03/how-to-install-vmware-tools-v4-on-ubuntu-11-10-server/

Written: March 13, 2012
Last Updated: April 27, 2012
Tested With: Ubuntu 12.04 LTS Server, Ubuntu 11.10 Server

All the guides I found on the Internet, including VMWare’s website were outdated in some way, so I decided to write a guide of my own. I just went through these steps from start to finish on a fresh server and had no problems.

  1. Use Install VMWare Tools option in VMWare Client/Console to attach media
  2. Update the server
    sudo apt-get update
    sudo apt-get upgrade
  3. Create the mount point
    sudo mkdir -p /media/cdrom
  4. Mount the ISO
    sudo mount /dev/cdrom /media/cdrom

    You should see the message: mount: block device /dev/sr0 is write-protected, mounting read-only

  5. Change Directory
    cd /media/cdrom
  6. Copy the tar file to your /tmp directory
    sudo cp VM*.tar.gz /tmp
  7. Install Build tools if necessary
    sudo apt-get install linux-headers-server build-essential
  8. Change Directory
    cd /tmp
  9. Unmount the ISO
    sudo umount /media/cdrom
  10. Expand the tar
    sudo tar xzvf VM*.tar.gz
  11. Change Directory
    cd vmware-tools-distrib
  12. To prevent a potential error in the install script on Ubuntu 11.10, create a special directory
    Unable to create symlink “/usr/lib64/libvmcf.so” pointing to file ”/usr/lib/vmware-tools/lib64/libvmcf.so/libvmcf.so”.

    sudo mkdir /usr/lib64
  13. Run the Install Script. The -d flag automatically answers the default to all questions. To customize it, just omit the -d.
    sudo ./vmware-install.pl -d
  14. Reboot
    sudo reboot

Let me know if this worked for you!

Also, please follow me on Twitter: @justinschier