Powershell: Installing google chrome browser

 To install chrome browser, using windows Powershell.

• Open Powershell as Administrator
• Paste below command

• 
    $LocalTempDir = $env:TEMP; $ChromeInstaller = "ChromeInstaller.exe"; (new-object    System.Net.WebClient).DownloadFile('http://dl.google.com/chrome/install/375.126/chrome_installer.exe', "$LocalTempDir\$ChromeInstaller"); & "$LocalTempDir\$ChromeInstaller" /silent /install; $Process2Monitor =  "ChromeInstaller"; Do { $ProcessesFound = Get-Process | ?{$Process2Monitor -contains $_.Name} | Select-Object -ExpandProperty Name; If ($ProcessesFound) { "Still running: $($ProcessesFound -join ', ')" | Write-Host; Start-Sleep -Seconds 2 } else { rm "$LocalTempDir\$ChromeInstaller" -ErrorAction SilentlyContinue -Verbose } } Until (!$ProcessesFound)
    
    

  Hope it helps

Arch Linux - Frequent or Random Freezes

I have bought a new Leveno Thinkpad AMD Series laptop and installed EndeavourOS in it. Endeavour is a Arch flavour and Arch is known for stability. Usually I am CentOS fan but as Corporate made its choice with CentOS future, I did research thoughting of sticking with one of my favorite Arch Linux. But Arch, you have to setup everything and its an interesting process though time taking. So I have chosen its flavour which comes with everything setup from GUI to Stack OS

One problem kept me frustrated that its freezes randomly and started connecting Ethernet adapter suddenly and that hangs the entire OS and sometimes I have experienced restarts as well.

On searching around Arch Linux forums I came across installed a LTS kernel solving the issue.

If you are also facing the issue you can solve it by installing LTS kernel with below commands

sudo pacman -S linux-lts linux-lts-headers
sudo grub-mkconfig -o /boot/grub/grub.cfg

And reboot your machine. While Booting make sure you are selecting the LTS kernel instead of regular one.

Hope it helps.

How to start sonarqube using dockers ?

SonarQube is an open-source platform developed by SonarSource for continuous inspection of code quality to perform automatic reviews with static analysis of code to detect bugs, code smells, and security vulnerabilities on 20+ programming languages. SonarQube offers reports on duplicated code, coding standards, unit tests, code coverage, code complexity, comments, bugs, and security vulnerabilities.

If you have Docker installed, then its very easy to have a SonarQube instance running your machine below instructions.

docker pull sonarqube

docker run -d --name sonarqube_container -p 9000:9000 sonarqube

In your browser access http://localhost:9000

And login with default credentials as below

username = admin password = admin

Hope it helps.
Thank you.

How to install nodejs in CentOS ?

If you choose default yum install of nodejs you will get 6.x release which is very old.
To install latest version of nodejs in centos you can execute below command
Command 1

  
  	curl -sL https://rpm.nodesource.com/setup_14.x | sudo bash -
   

You will get output as below

[vagrant@localhost ps-sinonjs]$ curl -sL https://rpm.nodesource.com/setup_14.x | sudo bash -

## Installing the NodeSource Node.js 14.x repo...


## Inspecting system...

+ rpm -q --whatprovides redhat-release || rpm -q --whatprovides centos-release || rpm -q --whatprovides cloudlinux-release || rpm -q --whatprovides sl-release
+ uname -m

## Confirming "el7-x86_64" is supported...

+ curl -sLf -o /dev/null 'https://rpm.nodesource.com/pub_14.x/el/7/x86_64/nodesource-release-el7-1.noarch.rpm'

## Downloading release setup RPM...

+ mktemp
+ curl -sL -o '/tmp/tmp.KNA1QsAK2D' 'https://rpm.nodesource.com/pub_14.x/el/7/x86_64/nodesource-release-el7-1.noarch.rpm'

## Installing release setup RPM...

+ rpm -i --nosignature --force '/tmp/tmp.KNA1QsAK2D'

## Cleaning up...

+ rm -f '/tmp/tmp.KNA1QsAK2D'

## Checking for existing installations...

+ rpm -qa 'node|npm' | grep -v nodesource

## Run `sudo yum install -y nodejs` to install Node.js 14.x and npm.
## You may also need development tools to build native addons:
     sudo yum install gcc-c++ make
## To install the Yarn package manager, run:
     curl -sL https://dl.yarnpkg.com/rpm/yarn.repo | sudo tee /etc/yum.repos.d/yarn.repo
     sudo yum install yarn

Your main instructions are here

## Run `sudo yum install -y nodejs` to install Node.js 14.x and npm.
## You may also need development tools to build native addons:
     sudo yum install gcc-c++ make
## To install the Yarn package manager, run:
     curl -sL https://dl.yarnpkg.com/rpm/yarn.repo | sudo tee /etc/yum.repos.d/yarn.repo
     sudo yum install yarn

I mean simply after executing command1 you can execute below commands and it will install latest Node.js version for you.

 sudo yum install -y nodejs 
 sudo yum install gcc-c++ make
 curl -sL https://dl.yarnpkg.com/rpm/yarn.repo | sudo tee /etc/yum.repos.d/yarn.repo
 sudo yum install yarn

Hope it helps.
Thank you for reading the article.

Install R Programming Language in Ubuntu

This post describe about installation steps for R- Programming Language.

For Windows we have direct exe file but for Linux its in a single click way but you can still do it below commands easily.

Open your terminal and type below commands as root user.

echo "
deb https://cloud.r-project.org/bin/linux/ubuntu xenial/
deb https://cloud.r-project.org/ trusty-backports main restricted universe" >> /etc/apt/sources.list
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 51716619E084DAB9
sudo apt-get update
sudo apt-get install -y r-base r-base-dev
sudo apt-get install r-cran-boot r-cran-class r-cran-cluster r-cran-codetools r-cran-foreign r-cran-kernsmooth r-cran-lattice r-cran-mass r-cran-matrix r-cran-mgcv r-cran-nlme r-cran-nnet r-cran-rpart r-cran-spatial r-cran-survival r-cran-rodbc

If any questions please dont hesitate to ask.

Thank you.

Installing Chef server in your CentOS 6.7 easily.

I have tried to install chef in my CentOS 6.7 but it was like complicated thing till today.

So many problems I have faced and I am giving them as precautions to you.

1. You should have minimum 1 Mbps unlimited connection. Atleast 5 GB data you are going to download.

2. Always you have to choose your current OS version builds, If you choose other version builds you will be stopped with library issues.

3. Atleast 6 - 7 GB of freespace

and Lot of patience.

I will give you in a simple way. Just open your terminal and turn into root user if you were not.

Then Download files from below links. Open them via browser and get the final link and download in your way.

1. https://packagecloud.io/chef/stable/packages/el/6/chef-server-core-12.3.1-1.el6.x86_64.rpm/download

2.https://packagecloud.io/chef/stable/packages/el/6/opscode-reporting-1.5.5-1.el6.x86_64.rpm/download

3.https://packagecloud.io/chef/stable/packages/el/6/opscode-push-jobs-server-1.1.6-1.x86_64.rpm/download

4.https://web-dl.packagecloud.io/chef/stable/packages/el/6/chef-sync-1.0.0~rc.7-1.el6.x86_64.rpm

5. https://packagecloud.io/chef/stable/packages/el/6/chef-manage-2.1.1-1.el6.x86_64.rpm/download

6. https://opscode-omnibus-packages.s3.amazonaws.com/el/6/x86_64/chefdk-0.10.0-1.el6.x86_64.rpm


After download all these files place them in any directory.

Now let us assume these files are in /home/mypc/chef directory.


Step 1:

rpm -ivh chef-server-core-12.3.1-1.el6.x86_64.rpm

chef-server-ctl reconfigure

chef-server-ctl user-create rajachef Raja G [email protected]  abc123 --filename /home/virt01/userkey.pem

Original Syntax : $ chef-server-ctl user-create user_name first_name last_name email password --filename FILE_NAME

chef-server-ctl org-create virt02 "virt02.myserver.com." --association_user virt02 --filename /home/virt02/virt02-validator.pem

Original Syntax: $ chef-server-ctl org-create short_name "full_organization_name" --association_user user_name --filename ORGANIZATION-validator.pem

Step 2: 

chef-server-ctl install opscode-manage --path /home/mypc/chef/chef-manage-2.1.1-1.el6.x86_64.rpm

chef-server-ctl reconfigure

opscode-manage-ctl reconfigure

Step 3: 

chef-server-ctl install opscode-push-jobs-server --path /home/mypc/chef/opscode-push-jobs-server-1.1.6-1.x86_64.rpm

chef-server-ctl reconfigure

opscode-push-jobs-server-ctl reconfigure

Step 4:

chef-server-ctl install chef-sync --path /home/mypc/chef/chef-sync-1.0.0~rc.7-1.el6.x86_64.rpm

chef-server-ctl reconfigure

chef-sync-ctl reconfigure

Step 5: 

chef-server-ctl install opscode-reporting --path /home/mypc/chef/ opscode-reporting-1.5.5-1.el6.x86_64.rpm

chef-server-ctl reconfigure

opscode-reporting-ctl reconfigure

Step 6:

And now install Chef Development Kit.

rpm -ivh chefdk-0.10.0-1.el6.x86_64.rpm

That's it chef server successfully installed in your system. To access chef , just open your browser and type localhost or IP of your PC. And you will get Login page and login with those credentials given initially at Step 1. 

If you are facing any issues please dont hesitate to ask. 

Thank you.

Regards

Raja

True transparency in CentOS

I have enabled transparency for my gnome terminal but I am always getting my desktop wallpaper as background of terminal after googling I found compiz missing.

Compiz is available in base repo itself.

After installing look for system-Preferences-WindowsTweak Manager and last option would give compiz and there enable transparency.

Install lshw in CentOS 6.X

While I am trying to use the command lshw in CentOS 6 , I just came to know that it is not installed and not available in main repo.

To install lshw in your CentOS PC .

1. Open Link :  http://pkgs.repoforge.org/lshw/?C=M;O=D
2. Copy download link of latest rpm package
3. Install with yum rather than using rpm , if you use rpm then it will fail due to missing dependencies. so better to use yum.

# wget http://pkgs.repoforge.org/lshw/lshw-2.17-1.el3.rf.i386.rpm
# yum install lshw-2.17-1.el3.rf.i386.rpm

After installing you can use it, simply type as lshw in the terminal.

lshw - simple meaning is list hardware. It will list total information about hardware in your PC or Server.

It will give very big output , so you better choose the desired output by using grep.

For example I just want VGA information :

[root@localhost ~]# lshw | grep VGA
             description: VGA compatible controller
             product: SVGA II Adapter
[root@localhost ~]#

Install & configure SSH in CentOS 6.X

Today I am going to start writing an article about SSH installation and configuration in CentOS. SSH means Secure Shell. When ever we are doing any kind of remote transmission though telnet,It will transmit the information as clear text and anybody is in the network can see whats being transferred and username/password and other sensitive information which supposed to be very secure.So to protect remote data operations SSH invented.
For Information : http://en.wikipedia.org/wiki/Secure_Shell
--------------------- How to install SSH ----------------------
Open your terminal and type

yum install openssh-server openssh-clients

After installing it , we have to make it as autostart with system boot. to make it so execute below command
chkconfig sshd on
To start,stop,restart and to know status of service

service sshd start
service sshd stop
service sshd restart
service sshd status

-----------------------------------------------------------------
Now we have to configure SSH.
------------------------------------------------------------------
Main purpose of SSH is remote host access , so to accept remote incoming connections we must allow the port in IPTables. So add the below line IPTables

vim /etc/sysconfig/iptables
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

Then restart IPTables

service iptables restart

---------------------------------------------------------------------
GIVE ME TIME TO UPDATE IT

Install osTicket in your Ubuntu

Hello Readers!!

Today we are going to know how to install & run osTicket , a open source(commercial too) Ticket management tool in your Ubuntu(Linux too).

Step 1: Open your terminal and run these below commands one after one.

sudo -i
aptitude install apache2 php5 libapache2-mod-php5 php5-imap
aptitude install mysql-server mysql-client php5-mysql
aptitude install phpmyadmin
aptitude install unzip

 php5enmod imap && sudo service apache2 restart

Those above commands will install Apache2,MySQL server,PHP, unzip software. If you dont aptitude installed you can install or instead you may use apt-get,yum similar tools.

Step 2: After installing , download osTicket from OS_Ticket_Download  and save it.

Step 3: Then Open your terminal and paste these commands one after one in your terminal

 mkdir /var/www/osticket
 mv  <here_path_to_OS_ticket> /var/www/osticket/
 unzip <here_path_to_OS_ticket>

Step 4: Next change your directory to extracted osticket and then do following steps.

 mv /uploads/* /var/www/osticket/

Step 5: Now rename ost-config.sample.php to ost-config.php with

 /var/www/osticket/include/ost-config.sample.php /var/www/osticket/include/ost-config.php

Then

Step 6: Now change permissions to global equal mode to ost-config.php with

chmod 777 /var/www/osticket/include/ost-config.php

Step 7: Then type as ifconfig to find your IP and then open your browser

http://<IP_here>/osticket/setup

From there you can follow remaining instructions with clicking at continue button.

Install & Configure DNS service in RHEL6

         DNS (Domain Name System) is one of the most dependable service in a network. All of us know that the DNS service resolves hostname into ip address and vice versa.  The DNS server translates the domain name into its corresponding ip address. So it makes us easy to remember the domain names instead of its ip address.

DNS Server Installation in RHEL6

         In this article we will see how to install and configure Primary and Scondary DNS server. The steps provided here are tested in RHEL6 64 bit edition.

Scenario

Domain Name : avr.com

Primary(Master) DNS Server Details:

Hostname             : server01.avr.com
IP Address           : 192.168.22.2
Subnetmask          : 255.255.255.0

Secondary(Slave) DNS Server Details:

Hostname             : server02.avr.com
IP Address           : 192.168.22.3
Subnetmask          : 255.255.255.0

Setup Primary(Master) DNS Server

1. Install DNS server
# yum install bind* -y

2. Configure DNS Server
#vim /etc/named.conf

options {
        listen-on port 53 { 192.168.22.2; };
//      listen-on-v6 port 53 { ::1; };    
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { 192.168.22.0/24; };
        allow-recursion { 192.168.22.0/24; };
        allow-transfer  { 192.168.22.3; };
        recursion yes;
        forwarders { 192.168.10.1; };   // DNS provided by ISP
        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside auto;
        /* Path to ISC DLV key */
        bindkeys-file "/etc/named.iscdlv.key";
};
logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};
zone "." IN {
        type hint;
        file "named.ca";
};
include "/etc/named.rfc1912.zones";

3. Create forward and reverse lookup zones
# vim /etc/named.rfc1912.zones

zone "avr.com" IN {
        type master;
        file "named.localhost";
        allow-update { none; };
};
zone "localhost" IN {
        type master;
        file "named.localhost";
        allow-update { none; };
};
zone "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
        type master;
        file "named.loopback";
        allow-update { none; };
};
zone "22.168.192.in-addr.arpa" IN {
        type master;
        file "named.loopback";
        allow-update { none; };
};
zone "0.in-addr.arpa" IN {
        type master;
        file "named.empty";
        allow-update { none; };
};


4. Edit the zone records file
Forward lookup zone file
# vim /var/named/named.localhost

$TTL 1D
@       IN SOA  server01.avr.com. root.server01.avr.com. (
                                        2       ; serial
                                        1D      ; refresh
                                        1H      ; retry
                                        1W      ; expire
                                        3H )    ; minimum
                NS      server01.avr.com.
                NS      server02.avr.com.
server01        A       192.168.22.2
server02        A       192.168.22.3
windesk01       A       192.168.22.12

Reverse lookup zone file
# vim /var/named/named.loopback

$TTL 1D
@       IN SOA  server01.avr.com. root.server01.avr.com. (
                                        2       ; serial
                                        1D      ; refresh
                                        1H      ; retry
                                        1W      ; expire
                                        3H )    ; minimum
        NS      server01.avr.com.
        NS      server02.avr.com.
2       PTR     server01.avr.com
3       PTR     server02.avr.com
12      PTR     windesk01.avr.com

5. Check the named configuration
# named-checkconf /etc/named.conf
# echo $?
0

# named-checkconf /etc/named.rfc1912.zones
# echo $?
0

6.Check zone configuration
Forward lookup zone configuration
# named-checkzone flz /var/named/named.localhost
zone flz/IN: loaded serial 2
OK

Reverse lookup zone configuration
# named-checkzone rlz /var/named/named.loopback
zone rlz/IN: loaded serial 2
OK

7. Add the following exception rules to firewall to accept DNS requests from the network 192.168.22.0/24
#iptables -t filter -A INPUT -p tcp -m state --state NEW --dport 53  -j ACCEPT
#iptables -t filter -A INPUT -p udp -m state --state NEW --dport 53 -j ACCEPT
#service iptables save
#service iptables restart

8. Make your server as DNS client itself.
#vim /etc/resolv.conf
search avr.com
nameserver 192.168.22.2
nameserver 192.168.10.1

9. Enable IP Forwarding
#vim /etc/sysctl.conf
      --> Modify the following line set ( 0 to 1)
net.ipv4.ip_forward = 1
#sysctl -p

10. Finally start the service
#service named start
#chkconfig named on

Setup Secondery(Slave) DNS Server

1. Install DNS server
# yum install bind* -y

2. Configure DNS Server
#vim /etc/named.conf

options {
        listen-on port 53 { 192.168.22.3; };
//      listen-on-v6 port 53 { ::1; };    
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { 192.168.22.0/24; };
        allow-recursion { 192.168.22.0/24; };
        allow-transfer  { none; };
        recursion yes;
        forwarders { 192.168.10.1; };   // DNS provided by ISP
        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside auto;
        /* Path to ISC DLV key */
        bindkeys-file "/etc/named.iscdlv.key";
};
logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};
zone "." IN {
        type hint;
        file "named.ca";
};
include "/etc/named.rfc1912.zones";

3. Create forward and reverse lookup zones
# vim /etc/named.rfc1912.zones

zone "avr.com" IN {
        type slave;
        file "slaves/named.localhost";
        masters { 192.168.22.2; };
};
zone "localhost" IN {
        type master;
        file "named.localhost";
        allow-update { none; };
};
zone "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
        type master;
        file "named.loopback";
        allow-update { none; };
};
zone "22.168.192.in-addr.arpa" IN {
        type slave;
        file "slaves/named.loopback";
        masters { 192.168.22.2; };
};
zone "0.in-addr.arpa" IN {
        type master;
        file "named.empty";
        allow-update { none; };
};

4. This step is not required for slave DNS, because the zone records will het updated automatically form master DNS (i.e 192.168.22.2)


5. Check the named configuration
# named-checkconf /etc/named.conf
# echo $?
0

# named-checkconf /etc/named.rfc1912.zones
# echo $?
0

6.Similar to step no.4 this step is not required for slave DNS, because the zone records will het updated automatically form master DNS (i.e 192.168.22.2). Note that the zone record files will be downloaded to the location "/var/named/slaves/ " on slave DNS as we configured it so in Step:3.

7. Add the following exception rules to firewall to accept DNS requests from the network 192.168.22.0/24

#iptables -t filter -A INPUT -p tcp -m state --state NEW --dport 53  -j ACCEPT
#iptables -t filter -A INPUT -p udp -m state --state NEW --dport 53 -j ACCEPT

#service iptables save
#service iptables restart

8. Make your server as DNS client itself.
#vim /etc/resolv.conf
search avr.com
nameserver 192.168.22.3
nameserver 192.168.22.2

9. Enable IP Forwarding
#vim /etc/sysctl.conf
      --> Modify the following line set ( 0 to 1)
net.ipv4.ip_forward = 1
#sysctl -p

10. Finally start the service
#service named start
#chkconfig named on