Hack The Sec-Leading Resource Of Linux Tutorial: Unix

How to find files containing specific text in Linux

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Find files containing specific text in Linux</div>
 
Find files containing specific text using grep command 
grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command g/re/p (globally search a regular expression and print), which has the same effect: doing a global search with the regular expression and printing all matching lines. Grep was originally developed for the Unix operating system, but later available for all Unix-like systems. 
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grep command syntax 
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">grep "text string to search” directory-path</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">grep [option] "text string to search” directory-path</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">grep -r "text string to search” directory-path</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">grep -r -H "text string to search” directory-path</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">egrep -R "word-1|word-2” directory-path</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">egrep -w -R "word-1|word-2” directory-path</pre>
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Find files containing specific text using grep command examples</div>
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In this example, we will search for 'PULSEAUDIO_SYSTEM_START' in all configuration files located in /etc directory.</div>
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Now there's a small problem, depending on your Linux distro, Find command Syntax can be slightly different.</div>
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*If you know the exact location and directory you're after, then use</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep "PULSEAUDIO_SYSTEM_START" /etc/default/pulseaudio 
PULSEAUDIO_SYSTEM_START=1
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*If you know the exact directory with the files containing that specific text, then use</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep "PULSEAUDIO_SYSTEM_START" /etc/default/*
grep: /etc/default/kdm.d: Is a directory
/etc/default/pulseaudio:PULSEAUDIO_SYSTEM_START=1
root@hackthesec:~#
</pre>
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If you don't know the exact location of the file that contains the specific text you’re looking for, then you need to search all sub-directories recursively.</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep -r "PULSEAUDIO_SYSTEM_START" /etc/default/*
/etc/default/pulseaudio:PULSEAUDIO_SYSTEM_START=1
root@hackthesec:~#</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep -R "PULSEAUDIO_SYSTEM_START" /etc/default/*
/etc/default/pulseaudio:PULSEAUDIO_SYSTEM_START=1
root@hackthesec:~#</pre>
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Now what if you are searching through a massive file and there might be many outputs similar to what you’re looking for.. you might want to use --col flag to color code your output which searching files containing specific strings.</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep --col 'usb 1-1.4' /var/log/messages
Apr 4 09:14:25 kali kernel: [1191164.780496] usb 1-1.4: new low-speed USB device number 21 using ehci-pci
root@hackthesec:~#</pre>
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Now I want to display all files with colorer output with containing specific text and instead of showing the whole content of the files</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep --col -r 'Linux version 3.14-kali1' /var/log/* | cut -d: -f1
/var/log/dmesg
/var/log/dmesg.0
/var/log/installer/syslog
root@hackthesec:~#</pre>
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When you're using grep, depending on the commands used and permission you have on the system, you might see any of the following errors.</div>
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* Input/output error</div>
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* recursive directory loop</div>
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* No such file or directory</div>
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* No such device or address</div>
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* Permission denied</div>
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If you want to hide all errors or warning message spamming your output window(specifically useful when you're trying to use grep on a script) generated by the grep command, append 2>/dev/null to grep command. This will send and hide unwanted output to /dev/null device:</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep -R "PULSEAUDIO_SYSTEM_START" /etc/* 2>/dev/null 
/etc/default/pulseaudio:PULSEAUDIO_SYSTEM_START=1
/etc/init.d/pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/init.d/pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc0.d/K01pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc0.d/K01pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc1.d/K01pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc1.d/K01pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc2.d/S20pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc2.d/S20pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc3.d/S20pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc3.d/S20pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc4.d/S20pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc4.d/S20pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc5.d/S20pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc5.d/S20pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
/etc/rc6.d/K01pulseaudio:PULSEAUDIO_SYSTEM_START=0
/etc/rc6.d/K01pulseaudio:if [ "$PULSEAUDIO_SYSTEM_START" != "1" ]; then
root@hackthesec:~#</pre>
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What if you're not sure about the case of the text you're after? You can use -i to ignore case.</div>
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Below example shows the difference between -i flag. First command didn’t find the text, second command did as we used -i flag to ignore case.</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">root@hackthesec:~# grep -r "pulseaudio_system_start" /etc/default/*
root@hackthesec:~# 
root@hackthesec:~# grep -i -r "pulseaudio_system_start" /etc/default/*
/etc/default/pulseaudio:PULSEAUDIO_SYSTEM_START=1
root@hackthesec:~#</pre>
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I always prefer using grep command with -r and --col flag in Debian Linux as -r complains less about permissions, files, directory etc. and of course some color helps on the eyes when you’re browsing through many lines.</div>
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How to find files containing specific text in Linux

Find files containing specific text in Linux Find files containing specific text using grep command grep is a command-line utility for ...

How-to extend a root LVM partition online

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Extend a root LVM partition online</div>
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There is also a quick remedy for the emergency situation when your root partition runs out of disk space. There is a feature specific to ext3 and ext4 that can help the goal of resolving the full disk situation. Unless explicitly changed during filesystem creation, both by default reserve five percent (5%) of a volume capacity to the superuser (root). 
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vg_main-lv_root
 ext4 8.4G 8.0G 952K 100% /
tmpfs tmpfs 499M 0 499M 0% /dev/shm
/dev/vda1 ext4 485M 33M 428M 8% /boot

# dumpe2fs /dev/vg_main/lv_root | grep 'Reserved block count'
dumpe2fs 1.41.12 (17-May-2010)
Reserved block count: 111513</pre>
It turned out 111513 of 4KB blocks were reserved for the superuser, which was exactly five percent of the volume capacity. 
 
How to enable it? 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># tune2fs -m 0 /dev/vg_main/lv_root 
tune2fs 1.41.12 (17-May-2010)
Setting reserved blocks percentage to 0% (0 blocks)
# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vg_main-lv_root
 ext4 8.4G 8.0G 437M 95% /
tmpfs tmpfs 499M 0 499M 0% /dev/shm
/dev/vda1 ext4 485M 33M 428M 8% /boot</pre>
 
Now that we have some free space on the root partition to work on we can extend the LVM partition: 
 
 
Create a new partition of appropriate size using fdisk 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">fdisk /dev/sdb1</pre>
 
This is a key sequence on the keyboard to create a new LVM type (8e) partition: 
 
n, p, 1, enter (accept default first sector), enter (accept default last sector), t, 8e, w 
 
 
Create a new Physical Volume 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># pvcreate /dev/sdb1
 Writing physical volume data to disk "/dev/sdb1"
 Physical volume "/dev/sdb1" successfully created</pre>
Extend a Volume Group 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># vgextend vg_main /dev/sdb1
 Volume group "vg_main" successfully extended</pre>
Extend your LVM 
 
 
- extend the size of your LVM by the amount of free space on PV 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># lvextend /dev/vg_main/lv_root /dev/sdb1
 Extending logical volume lv_root to 18.50 GiB
 Logical volume lv_root successfully resized</pre>
- or with a given size 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">lvextend -L +10G /dev/vg_main/lv_root</pre>
 
Finally resize the file system online 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># resize2fs /dev/vg_main/lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_main/lv_root is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/vg_main/lv_root to 4850688 (4k) blocks.
The filesystem on /dev/vg_main/lv_root is now 4850688 blocks long.</pre>
Now we can set the reserved blocks back to the default percentage - 5% 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">tune2fs -m 5 /dev/mapper/vg_main-lv_root
Results:

# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vg_main-lv_root
 ext4 19G 8.0G 9.4G 46% /
tmpfs tmpfs 499M 0 499M 0% /dev/shm
/dev/vda1 ext4 485M 33M 428M 8% /boot</pre>
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How-to extend a root LVM partition online

Extend a root LVM partition online There is also a quick remedy for the emergency situation when your root partition runs out of disk s...

Enabling email authentication (SPF and DKIM) for all existing accounts – cPanel/WHM

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Enabling email authentication (SPF and DKIM)</h1>
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cPanel is a <a href="http://www.hackthesec.co.in/search/label/Linux%20Tutorial">Linux-based</a> web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site. cPanel utilizes a 3 tier structure that provides capabilities for administrators, resellers, and end-user website owners to control the various aspects of website and server administration through a standard web browser.</div>
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In addition to the GUI, cPanel also has command line and API-based access that allows third party software vendors, web hosting organizations, and developers to automate standard system administration processes.</div>
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cPanel is designed to function either as a dedicated server or virtual private server. The latest cPanel version supports installation on CentOS, Red Hat Enterprise Linux (RHEL), and CloudLinux OS. cPanel 11.30 is the last major version to support FreeBSD.</div>
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Application-based support includes Apache, PHP, MySQL, PostgreSQL, Perl, and BIND (DNS). Email based support includes POP3, IMAP, and SMTP services. cPanel is accessed via https on port 2083</div>
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cPanel script to enable SPF via commandline:</div>

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<ins class="adsbygoogle" data-ad-client="ca-pub-5744890361111211" data-ad-slot="1658755283" style="display: inline-block; height: 15px; width: 728px;"></ins></center>
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Syntax</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># /usr/local/cpanel/bin/spf_installer $username</pre>
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Where, $username is the cPanel user name</div>
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cPanel script to enable DKIM via commandline: 
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Syntax</div>
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># /usr/local/cpanel/bin/dkim_keys_install $username</pre>
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Replace $username with the actual cPanel username.</div>
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The above commands will help you to enable email authentications for single cPanel users. If you have hundreds of accounts and you want to enable SPF and DKIM for all accounts, please follow the simple for loop.</div>
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Here we can get the cPanel usernames from "/var/cpanel/users". Then give that to installations scripts. Please see the sample script below:</div>
<div>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">for username in `ls -A /var/cpanel/users` ; do
 /usr/local/cpanel/bin/dkim_keys_install $username &&
 /usr/local/cpanel/bin/spf_installer $username ; done</pre>
</div>
<div style="color: #333333; font-family: verdana, geneva, sans-serif; font-size: 15px;">
Thanks for support</div>
</div>
<div style="color: #333333; font-family: verdana, geneva, sans-serif; font-size: 15px;">
<a href="http://www.hackthesec.co.in/">www.hackthesec.co.in</a></div>
</div>
</div>

Enabling email authentication (SPF and DKIM) for all existing accounts – cPanel/WHM

Enabling email authentication (SPF and DKIM) cPanel is a Linux-based web hosting control panel that provides a graphical interface and...

How to Install Go 1.7 on Ubuntu 16.04 / 14.04 / CentOS 7 / Fedora 24

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Install Go 1.7 on Ubuntu 16.04 / 14.04 / CentOS 7 / Fedora 24 
 
Go (often referred to as golang) is a free and open source programming language created at Google in 2007 by Robert Griesemer, Rob Pike, and Ken Thompson. It is a compiled, statically typed language in the tradition of Algol and C, with garbage collection, limited structural typing, memory safety features and CSP-style concurrent programming features added. 
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBBvny9pyLCA-DGCTjvXwcsfTDyRGFmfSw3muCt-XMd3aEDl_ZXEUtltnvg2NFm9Y73eB_VOu_bmnO9GbFQp1pDoWLHLQ9gK6WUEI0B-_fkqUzvIseI95633MHVY_ictfMUMH1434iFeEV/s1600/appenginegophercolor.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBBvny9pyLCA-DGCTjvXwcsfTDyRGFmfSw3muCt-XMd3aEDl_ZXEUtltnvg2NFm9Y73eB_VOu_bmnO9GbFQp1pDoWLHLQ9gK6WUEI0B-_fkqUzvIseI95633MHVY_ictfMUMH1434iFeEV/s1600/appenginegophercolor.jpg" /></a></div>
 
The language was announced in November 2009; it is used in some of Google's production systems,as well as by other firms. Two major implementations exist: Google's Go compiler, "gc", is developed as open source software and targets various platforms including Linux, OS X, Windows, various BSD and Unix versions, and since 2015 also mobile devices, including smartphones.A second compiler, gccgo, is a GCC frontend. The "gc" toolchain is self-hosting since version 1.7 
 
Download and Install Go Language: 
Switch to the root user. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$ su -

### Ubuntu 16.04 / 14.04 ###

# apt-get update
# apt-get -y upgrade

### CentOS / RHEL / Fedora ###

# yum -y update
</pre>
Download the Go language binary package using the following command. Alternatively, you can visit <a href="https://golang.org/dl/">Go Language download</a> page to download the latest version of Go. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># wget https://storage.googleapis.com/golang/go1.7.1.linux-amd64.tar.gz</pre>
Extract the archive and move it to /usr/local. You can also place the Go lang binary to your custom location instead of /usr/local. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># tar -zxvf go1.7.1.linux-amd64.tar.gz -C /usr/local/</pre>
Setup Go Environment variables: 
 
 
Setup two important variables for Go, GOROOT (PATH) and GOPATH. Add /usr/local/go/bin to your path variable.run below command (temporary) or place the following command in /etc/profile or $HOME/.profile file for persistent across sessions. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">export PATH=$PATH:/usr/local/go/bin</pre>
For Go custom location replace /usr/local/go/bin/ with /path/to/bin/ directory. 
 
 
GOPATH is a Go environment variable for your project workspace. Create a workspace directory called "projectwork" in your home directory. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">mkdir $HOME/projectwork</pre>
Set GOPATH variable run below command (temporary) or place the following command in /etc/profile or $HOME/.profile file for persistent across sessions. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">export GOPATH=$HOME/projectwork</pre>
Verify Go Installation: 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># go version
go version go1.7.1 linux/amd64</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># go env

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/root/projectwork"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"</pre>
Create your first project: 
The workspace called "projectwork" located in $HOME directory. I am a root user, in my case "/root/projectwork" is my workspace. goto your workspace using below command 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># cd $GOPATH
or
# cd $HOME/work</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># mkdir -p src/hello</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># vi src/hello/hello.go</pre>
and place the following content in the hello.go file. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">package main

import "fmt"

func main() {
 fmt.Printf("Welcome To hackthesec\n")
}</pre>
Compile it with go command. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># go install hello</pre>
go command will put an executable command (hello) inside the bin directory of your workspace. Execute the executable using the following command. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># $GOPATH/bin/hello</pre>
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">Welcome To hackthesec</pre>
Thanks for reading.. 
<a href="http://www.hackthesec.co.in/">www.hackthesec.co.in</a> 
 </div>

How to Install Go 1.7 on Ubuntu 16.04 / 14.04 / CentOS 7 / Fedora 24

Install Go 1.7 on Ubuntu 16.04 / 14.04 / CentOS 7 / Fedora 24 Go (often referred to as golang) is a free and open source programming lang...

How to Install and Configure phpLDAPAdmin on CentOS 7 / Ubuntu 16.04

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<div style="text-align: center;">
Install and Configure phpLDAPAdmin on Linux</div>
<div style="text-align: center;">
 </div>
phpLDAPadmin is a web application for administering Lightweight Directory Access Protocol (LDAP) servers.It's written in the PHP programming language, and is licensed  
 
under the GNU General Public License. The application is available in 14 languagesand supports UTF-8 encoded directory strings. 
 
<a href="http://www.hackthesec.co.in/2016/11/how-to-migrate-local-users-to-ldap.html" itemprop="url" style="background-color: white; display: block; font-family: "Open Sans", serif, sans-serif; font-weight: 600; text-decoration: none;">How to migrate local users to LDAP accounts</a>

On CentOS / RHEL: 
 
 
phpLDAPAdmin is not available in the main repository, so you need to enable <a href="http://www.hackthesec.co.in/2016/01/how-to-install-epel-repo-on-centos-and.html">EPEL repository for Redhat</a> based derivatives. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">### For RHEL 7 ###

# rpm -ivh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

### For CentOS 7 ###

# yum -y install epel-release</pre>
Install phpLDAPAdmin: 
<div style="clear: both; margin: 10px 0;">
<center>
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</div>
Install phpLDAPAdmin using "yum" on CentOS and "apt-get" on Ubuntu. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">### CentOS 7 / RHEL 7 ###

# yum install -y phpldapadmin

### Ubuntu 16.04 ###

$ sudo apt-get update
$ sudo apt-get install -y phpldapadmin</pre>
Configure Apache virtual host on CentOS 7 / RHEL 7: 
 
Default phpLDAPAdmin web config file in /etc/httpd/conf.d directory, it has rules and access permission. phpLDAPAdmin can be accessed only from the localhost (127.0.0.1) check the bellow settings. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># vi /etc/httpd/conf.d/phpldapadmin.conf</pre>
Update the configuration file shown like below.  
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">Alias /phpldapadmin /usr/share/phpldapadmin/htdocs
Alias /ldapadmin /usr/share/phpldapadmin/htdocs

usr/share/phpldapadmin/htdocs>
 <IfModule mod_authz_core.c>
 # Apache 2.4
 # Require local
 Require all granted
 IfModule>
 <IfModule !mod_authz_core.c>
 # Apache 2.2
 Order Deny,Allow
 Deny from all
 Allow from 127.0.0.1
 Allow from ::1
 </IfModule>
</Directory></pre>
Start the apache service in CentOS 7 / RHEL 7. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># systemctl restart httpd.service</pre>
Configure the FirewallD to allow external machines to access the dashboard (CentOS / RHEL). 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># firewall-cmd --permanent --zone=public --add-service=http
# firewall-cmd --reload</pre>
Configure phpLDAPAdmin: 
<div style="clear: both; margin: 10px 0;">
<center>
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<ins class="adsbygoogle" data-ad-client="ca-pub-5744890361111211" data-ad-slot="1658755283" style="display: inline-block; height: 15px; width: 728px;"></ins></center>
</div>
phpLDAPadmin by modifying some of its configuration values. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">### CentOS 7 / RHEL 7 ###

# vi /etc/phpldapadmin/config.php

### Ubuntu 16.04 ###

$ sudo nano /etc/phpldapadmin/config.php</pre>
A handy name that will appear in the left tree viewer and throughout phpLDAPadmin to identify this LDAP server to users. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('server','name','HackTheSec Local LDAP Server');</pre>
If you are planning to manage the LDAP server other than localhost then you can modify the below parameter. (Optional) 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('server','host','127.0.0.1');</pre>
To connect to the LDAP server which listens on the non-standard port. (Optional) 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('server','port',389);</pre>
Array of base domain names of your LDAP server. ( Must be set in Ubuntu 16.04) 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('server','base',array('dc=hackthesec,dc=local'));</pre>
On CentOS 7 / RHEL 7: 
 
Uncomment the line 397 and comment out the 398, like below. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('login','attr','dn');
// $servers->setValue('login','attr','uid');</pre>
If you have SELinux enabled on CentOS 7 / RHEL 7 then run this command. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;"># setsebool -P httpd_can_connect_ldap on</pre>
Access phpLDAPAdmin: 
 
Open up the web browser and navigate it to the following URL. 
http://your-ip-add-ress/phpldapadmin 
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgC4H8H_DLb4Dyi-bXqjSL_veED94b5UY1xEBUIxIukoKxr8EseQ1Au9cgKdVHXb8OCyT66b5eGIqh2geQkEDvt_BEHCWoMgVeHRjkpl6VQJte7BronBi7aF3MyWpPysTJsax-flqu-9_pn/s1600/xConfigure-phpLDAPAdmin-on-CentOS-7.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgC4H8H_DLb4Dyi-bXqjSL_veED94b5UY1xEBUIxIukoKxr8EseQ1Au9cgKdVHXb8OCyT66b5eGIqh2geQkEDvt_BEHCWoMgVeHRjkpl6VQJte7BronBi7aF3MyWpPysTJsax-flqu-9_pn/s1600/xConfigure-phpLDAPAdmin-on-CentOS-7.jpg" /></a></div>
Click on the "login" link that is visible on the left-hand side of the page. You will be taken to the login page, log in using the LDAP root (ldapadm) account in the form of "cn=ldapadm,dc=hackthesec,dc=local". 
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzDHfhjd21ThBzLktS38edIbS5plu0X9viwsIy1xxjmmfO4nzjkSx2BIVG8rQtogqCMvvOhpEBQP42DJ1ByYMAzHnu5vRaRzqGc1s8lJZRuI_39EVv-RkzDe7BtsxvM_pQXOST07Xn8FBF/s1600/phpLDAPAdmin-Login.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzDHfhjd21ThBzLktS38edIbS5plu0X9viwsIy1xxjmmfO4nzjkSx2BIVG8rQtogqCMvvOhpEBQP42DJ1ByYMAzHnu5vRaRzqGc1s8lJZRuI_39EVv-RkzDe7BtsxvM_pQXOST07Xn8FBF/s1600/phpLDAPAdmin-Login.jpg" /></a></div>
If you have below values set in /etc/phpldapadmin/config.php file then the Login DN: will be automatically pre-populated. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">$servers->setValue('login','bind_id','cn=ldapadm,dc=hackthesec,dc=local');</pre>
Now you can start managing your LDAP server via phpLDAPAdmin. 
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhelI5SDN1eQLU2LR0SwZS9nCJFSxRK28tJP4p4X5ktsrdANL0qO6F5om2W_4YtQ0n2uYFrl-EvATpvjdAntPlGixSIfUEhJRJbb6bMChJrp9duAkQUw8B9q00iC0hw51aulrNteFoMKewP/s1600/LOCAL_LDAP.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhelI5SDN1eQLU2LR0SwZS9nCJFSxRK28tJP4p4X5ktsrdANL0qO6F5om2W_4YtQ0n2uYFrl-EvATpvjdAntPlGixSIfUEhJRJbb6bMChJrp9duAkQUw8B9q00iC0hw51aulrNteFoMKewP/s1600/LOCAL_LDAP.jpg" /></a></div>
 
Thanks for watching ... 
<a href="http://www.hackthesec.co.in/">www.hackthesec.co.in</a></div>

How to Install and Configure phpLDAPAdmin on CentOS 7 / Ubuntu 16.04

Install and Configure phpLDAPAdmin on Linux phpLDAPadmin is a web application for administering Lightweight Directory Access Protocol (...

How to Install and Configure GlusterFS on Ubuntu 16.04 / Debian 8

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<div style="text-align: center;">
Install and Configure GlusterFS(CDN) on Linux</div>
GlusterFS is a scale-out network-attached storage file system. It has found applications including cloud computing, streaming media services, and content delivery networks. GlusterFS was developed originally by Gluster, Inc. and then by Red Hat, Inc., as a result of Red Hat acquiring Gluster in 2011. 
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</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdJnOaTc6MSKjAYBe4dn9k7e5ZNAFkeEU6mYamvzREsHufPleqXVl-gUhp_ySHmxGUIob5XPa-sn_QU6gFyF5eqibhdyWQt13Mz79YzQFrKVzjxHtVmOfuh21wD5XR7X6ZIMK338_-oJgO/s1600/Configure-GlusterFS-on-Ubuntu-16.04.png" imageanchor="1"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdJnOaTc6MSKjAYBe4dn9k7e5ZNAFkeEU6mYamvzREsHufPleqXVl-gUhp_ySHmxGUIob5XPa-sn_QU6gFyF5eqibhdyWQt13Mz79YzQFrKVzjxHtVmOfuh21wD5XR7X6ZIMK338_-oJgO/s1600/Configure-GlusterFS-on-Ubuntu-16.04.png" /></a></div>
 
 
In June 2012, Red Hat Storage Server was announced as a commercially supported integration of GlusterFS with Red Hat Enterprise Linux.Red Hat bought Inktank Storage in April 2014, which is the company behind the Ceph distributed file system, and re-branded GlusterFS-based Red Hat Storage Server to "Red Hat Gluster Storage" 
 
Requirements: 
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Here, we are going to configure GlusterFS volume with two replicas. Make sure you have two 64bit systems (either virtual or physical) with 1GB of memory, and one spare hard disk on each system. 
 
gluster1.hackthesec.local|192.168.12.16|Ubuntu 16.04|1GG|/dev/sdb (5GB)--Node 1 
 
gluster2.hackthesec.local|192.168.12.17|Debian 8|1GB|/dev/sdb (5GB)--Node 2 
 
client.hackthesec.local|192.168.12.8|CentOS 7 / Debian|NA|NA|Client Machine 
 
Configure DNS: 
 
GlusterFS components use DNS for name resolutions, so configure either DNS or set up a hosts entry. If you do not have a DNS on your environment, modify /etc/hosts file and update it accordingly. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo vi /etc/hosts

192.168.12.16 gluster1.hackthesec.local gluster1
192.168.12.17 gluster2.hackthesec.local gluster2
192.168.12.20 client.hackthesec.local client</pre>
Add GlusterFS Repository: 
 
Before proceeding to the installation, we need to configure GlusterFS repository on both storage nodes. Follow the instruction to add the repository to your system. 
 
Debian: 
 
Install support package for https transactions. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo apt-get install -y lsb-release
sudo apt-get install -y apt-transport-https</pre>
Add the public key for GlusterFS repository. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">wget -O - http://download.gluster.org/pub/gluster/glusterfs/LATEST/rsa.pub | sudo apt-key add -
echo deb https://download.gluster.org/pub/gluster/glusterfs/LATEST/Debian/$(lsb_release -sc)/apt $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/gluster.list</pre>
Ubuntu 16.04 / 14.04: 
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<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo apt-get install -y software-properties-common
sudo add-apt-repository ppa:gluster/glusterfs-3.8</pre>
Install GlusterFS: 
Once you have added the repository on your systems, we are good to go for the installation of GlusterFS. 
 
 
Update the repository cache. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo apt-get update</pre>
Install GlusterFS package using the following command. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo apt-get install -y glusterfs-server</pre>
Start the glusterfs-server service on all gluster nodes. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo service glusterfs-server start</pre>
Verify that the glusterfs service is running fine. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">hackthesec@gluster1:~$ sudo service glusterfs-server status

● glusterfs-server.service - LSB: GlusterFS server
   Loaded: loaded (/etc/init.d/glusterfs-server; bad; vendor preset: enabled)
   Active: active (running) since Sat 2016-09-24 21:47:20 IST; 1min 6s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 1570 ExecStop=/etc/init.d/glusterfs-server stop (code=exited, status=0/SUCCESS)
  Process: 1664 ExecStart=/etc/init.d/glusterfs-server start (code=exited, status=0/SUCCESS)
    Tasks: 7 (limit: 512)
   Memory: 25.5M
      CPU: 3.552s
   CGroup: /system.slice/glusterfs-server.service
           └─1673 /usr/sbin/glusterd -p /var/run/glusterd.pid

Sep 24 21:47:16 gluster1.hackthesec.local systemd[1]: Starting LSB: GlusterFS server...
Sep 24 21:47:16 gluster1.hackthesec.local glusterfs-server[1664]: * Starting glusterd service glusterd
Sep 24 21:47:20 gluster1.hackthesec.local glusterfs-server[1664]: ...done.
Sep 24 21:47:20 gluster1.hackthesec.local systemd[1]: Started LSB: GlusterFS server.</pre>
Configure Firewall: 
 
You would need to either disable the firewall or configure the firewall to allow all connections within a cluster. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo iptables -I INPUT -p all -s <ip-address> -j ACCEPT</pre>
Add Storage: 
Assuming that you have one spare hard disk on your machine, /dev/sdb is the one I will use here for a brick. Create a single partition on the spare hard disk shown like below. 
 
 
You would need to perform the below steps on both nodes. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none !important; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px !important; margin-top: 10px !important; overflow: auto; padding: 10px !important; width: auto !important; word-break: break-all;">sudo iptables -I INPUT -p all -s <ip-address> -j ACCEPT</pre>
Add Storage: 
 
Assuming that you have one spare hard disk on your machine, /dev/sdb is the one I will use here for a brick. Create a single partition on the spare hard disk shown like below. 
 
You would need to perform the below steps on both nodes. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; color: white; font-family: monospace, serif; font-size: 14px; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">sudo fdisk /dev/sdb</pre>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi77o2pDFqlYzs1YeLig6t_MyZiWZDp-gZdp520aemOh3gJRCGdVn6dTfCQiZGYpfiNOVTEB0sSQDTNJ7J_m0dpeJZv7hPWlF23BhrMIt6h1R3256r4AzsIGbGroniCMLuCVpl2DQLp9v01/s1600/xCreate-a-Partition.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi77o2pDFqlYzs1YeLig6t_MyZiWZDp-gZdp520aemOh3gJRCGdVn6dTfCQiZGYpfiNOVTEB0sSQDTNJ7J_m0dpeJZv7hPWlF23BhrMIt6h1R3256r4AzsIGbGroniCMLuCVpl2DQLp9v01/s1600/xCreate-a-Partition.png" /></a></div>


Format and Mount the created partition with the filesystem of your choice.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">sudo mkfs.ext4 /dev/sdb1
sudo mkdir -p /data/gluster
sudo mount /dev/sdb1 /data/gluster
echo "/dev/sdb1 /data/gluster ext4 defaults 0 0" | sudo tee --append /etc/fstab
</pre>
Configure GlusterFS on Ubuntu 16.04: 
 
Before creating a volume, we need to create trusted storage pool by adding gluster2.hackthesec.local. You can run GlusterFS configuration commands on any one server in the cluster will execute the same command on all other servers. 
 
Here I will run all GlusterFS commands in gluster1.hackthesec.local node. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo gluster peer probe gluster2.hackthesec.local
peer probe: success.

hackthesec@gluster1:~$ sudo gluster peer status

Number of Peers: 1

Hostname: gluster2.hackthesec.local
Uuid: 51470928-dfa8-42e1-a221-d7bbcb8c13bd
State: Peer in Cluster (Connected)

hackthesec@gluster1:~$ sudo gluster pool list

UUID Hostname State
51470928-dfa8-42e1-a221-d7bbcb8c13bd gluster2.hackthesec.local Connected
dc7c1639-d21c-4adf-b28f-5150229e6980 localhost Connected
</pre>
Setup GlusterFS Volume: 
 
Create a brick (directory) called "gvol0" in the mounted file system on both nodes. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">sudo mkdir -p /data/gluster/gvol0</pre>





Since we are going to use replicated volume, so create the volume named "gvol0" with two replicas.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo gluster volume create gvol0 replica 2 gluster1.hackthesec.local:/data/gluster/gvol0 gluster2.hackthesec.local:/data/gluster/gvol0
volume create: gvol0: success: please start the volume to access data</pre>

Start the volume.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo gluster volume start gvol0
volume start: gvol0: success</pre>

Check the status of the created volume. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo gluster volume info gvol0

Volume Name: gvol0
Type: Replicate
Volume ID: ca102e4b-6cd1-4d9d-9c5a-03b882c76da0
Status: Started
Snapshot Count: 0
Number of Bricks: 1 x 2 = 2
Transport-type: tcp
Bricks:
Brick1: gluster1.hackthesec.local:/data/gluster/gvol0
Brick2: gluster2.hackthesec.local:/data/gluster/gvol0
Options Reconfigured:
transport.address-family: inet
performance.readdir-ahead: on
nfs.disable: on</pre>
Setup GlusterFS Client: 
 
Install glusterfs-client package to support the mounting of GlusterFS filesystems. Run all commands as root user. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">$ su -

### CentOS / RHEL ###
yum install -y glusterfs-client

### Ubuntu / Debian ###
apt-get install -y glusterfs-client</pre>



Create a directory to mount the GlusterFS filesystem. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">mkdir -p /mnt/glusterfs</pre>

Now, mount the GlusterFS filesystem to /mnt/glusterfs using the following command.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">mount -t glusterfs gluster1.hackthesec.local:/gvol0 /mnt/glusterfs</pre>
You can also use gluster2.hackthesec.local instead of gluster1.hackthesec.com in the above command. 
 
Verify the mounted GlusterFS filesystem. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">[root@client ~]# df -hP /mnt/glusterfs
Filesystem Size Used Avail Use% Mounted on
gluster1.hackthesec.local:/gvol0 4.8G 11M 4.6G 1% /mnt/glusterfs</pre>



You can also use below command to verify the GlusterFS filesystem.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">[root@client ~]# cat /proc/mounts
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
devtmpfs /dev devtmpfs rw,seclabel,nosuid,size=490448k,nr_inodes=122612,mode=755 0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,seclabel,nosuid,nodev 0 0
devpts /dev/pts devpts rw,seclabel,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,seclabel,nosuid,nodev,mode=755 0 0
tmpfs /sys/fs/cgroup tmpfs ro,seclabel,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpuacct,cpu 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,nosuid,nodev,noexec,relatime,hugetlb 0 0
cgroup /sys/fs/cgroup/net_cls cgroup rw,nosuid,nodev,noexec,relatime,net_cls 0 0
configfs /sys/kernel/config configfs rw,relatime 0 0
/dev/mapper/centos-root / xfs rw,seclabel,relatime,attr2,inode64,noquota 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=25,pgrp=1,timeout=300,minproto=5,maxproto=5,direct 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,seclabel,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
mqueue /dev/mqueue mqueue rw,seclabel,relatime 0 0
/dev/mapper/centos-home /home xfs rw,seclabel,relatime,attr2,inode64,noquota 0 0
/dev/sda1 /boot xfs rw,seclabel,relatime,attr2,inode64,noquota 0 0
tmpfs /run/user/0 tmpfs rw,seclabel,nosuid,nodev,relatime,size=100136k,mode=700 0 0
gluster1.hackthesec.local:/gvol0 /mnt/glusterfs fuse.glusterfs rw,relatime,user_id=0,group_id=0,default_permissions,allow_other,max_read=131072 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0</pre>

Add below entry to /etc/fstab for automatically mounting during system boot.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">gluster1.hackthesec.local:/gvol0 /mnt/glusterfs glusterfs defaults,_netdev 0 0</pre>
Test GlusterFS Replication and High-Availability: 
 
GlusterFS Server Side: 
 
To check the replication, mount the created GlusterFS volume on the same storage node. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo mount -t glusterfs gluster1.hackthesec.local:/gvol0 /mnt
hackthesec@gluster2:~$ sudo mount -t glusterfs gluster2.hackthesec.local:/gvol0 /mnt</pre>



Data inside the /mnt directory of both nodes will always be same (replication). 
 
GlusterFS Client Side: 
Let’s create some files on the mounted filesystem on the client.hackthesec.local. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">touch /mnt/glusterfs/file1
touch /mnt/glusterfs/file2

[root@client ~]# ll /mnt/glusterfs/
total 0
-rw-r--r--. 1 root root 0 Sep 26 11:22 file1
-rw-r--r--. 1 root root 0 Sep 26 11:22 file2
</pre>


Test the both GlusterFS nodes whether they have same data inside /mnt. 
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ ll /mnt/
total 12
drwxr-xr-x 4 root root 4096 Sep 26 20:52 ./
drwxr-xr-x 24 root root 4096 Sep 25 21:57 ../
-rw-r--r-- 1 root root 0 Sep 26 20:52 file1
-rw-r--r-- 1 root root 0 Sep 26 20:52 file2

hackthesec@gluster2:~$ ls -al /mnt/
total 12
drwxr-xr-x 4 root root 4096 Sep 26 06:30 .
drwxr-xr-x 23 root root 4096 Sep 24 08:39 ..
-rw-r--r-- 1 root root 0 Sep 26 2016 file1
-rw-r--r-- 1 root root 0 Sep 26 2016 file2</pre>
As you know, we have mounted GlusterFS volume from gluster1.hackthesec.local on client.hackthesec.local, now it is the time to test the high-availability of the volume by shutting down the node. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo poweroff</pre>

Now test the availability of the files, you would see files that we created recently even though the node is down.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">[root@client ~]# ll /mnt/glusterfs/
total 0
-rw-r--r--. 1 root root 0 Sep 26 11:22 file1
-rw-r--r--. 1 root root 0 Sep 26 11:22 file2</pre>

Create some more files on the GlusterFS filesystem to check the replication. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">touch /mnt/glusterfs/file3
touch /mnt/glusterfs/file4</pre>

Verify the files count.
 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">[root@client ~]# ll /mnt/glusterfs/
total 0
-rw-r--r--. 1 root root 0 Sep 26 11:22 file1
-rw-r--r--. 1 root root 0 Sep 26 11:22 file2
-rw-r--r--. 1 root root 0 Sep 26 11:26 file3
-rw-r--r--. 1 root root 0 Sep 26 11:26 file4</pre>
Since the gluster1 is down, all your data’s are now written on gluster2.hackthesec.local due to High-Availability. Now power on the node1 (gluster1.hackthesec.local). 
 
Check the /mnt of the gluster1.hackthesec.local; you should see all four files in the directory, this confirms the replication is working as expected. 
<pre style="background: rgb(68, 67, 65); border-radius: 6px; border: 1px solid rgb(227, 227, 227); box-sizing: border-box; clear: none; margin-bottom: 10px; margin-top: 10px; overflow: auto; padding: 10px; width: auto; word-break: break-all;">hackthesec@gluster1:~$ sudo mount -t glusterfs gluster1.hackthesec.local:/gvol0 /mnt
[sudo] password for hackthesec:

hackthesec@gluster1:~$ ll /mnt/
total 12
drwxr-xr-x 4 root root 4096 Sep 26 20:59 ./
drwxr-xr-x 24 root root 4096 Sep 25 21:57 ../
-rw-r--r-- 1 root root 0 Sep 26 20:52 file1
-rw-r--r-- 1 root root 0 Sep 26 20:52 file2
-rw-r--r-- 1 root root 0 Sep 26 20:56 file3
-rw-r--r-- 1 root root 0 Sep 26 20:56 file4</pre>
Thanks for watching... 
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