How To Install Open vSwitch on CentOS 8 | RHEL 8

Here we’ll use the os-net-confi script for the configuration of Open vSwtich on CentOS/RHEL. So, follow the below steps to configure the Open vSwitch on your system.

Step 1: Install os-net-config Tool

To configure the Open vSwitch we need os-net-config tool as it will help us to perform configuration steps more easily. It provides the configuration of host networking using YAML or JSON files format.

By default, os-net-config use the YAML file that can be located under /etc/os-net-config/config.yaml. You can also customize this by –config-file(-c) CLI option.

Installing os-net-config by using OpenStack Repository

Hit the following command to install the os-net-config tool using OpenStack repository if you’ve already configured it.

sudo yum install os-net-config

Find out more details about the package by typing

[sabi@localhost ~]$ rpm -qi os-net-config
Name : os-net-config
Version : 11.3.1
Release : 1.el8
Architecture: noarch
Install Date: Sat 08 Aug 2020 02:20:02 AM EDT
Group : Unspecified
Size : 3760703
License : ASL 2.0
Signature : RSA/SHA1, Sun 19 Apr 2020 12:34:05 PM EDT, Key ID f9b9fee7764429e6
Source RPM : os-net-config-11.3.1-1.el8.src.rpm
Build Date : Fri 28 Feb 2020 08:55:33 AM EST
Build Host : c1be.rdu2.centos.org
Relocations : (not relocatable)
Packager : CBS cbs@centos.org
Vendor : CentOS
URL : http://pypi.python.org/pypi/os-net-config
Summary : Host network configuration tool
Description :
Host network configuration tool for OpenStack.

Installing os-net-config with the help of Pip

You can also install the os-net-config tool using pip or pip3 as it is distributed as python package.

CentOS 8:

sudo dnf install python3-pip

CentOS 7:

sudo yum install -y epel-release
sudo yum -y install python-pip
sudo pip install os-net-config

Make sure to verify the PATH once the installation finished.

[sabi@localhost ~]$ which os-net-config
/usr/bin/os-net-config

Step 2: Configuring Open vSwitch by using os-net-config

Let’s dive into the configuration of Open vSwitch by using os-net-config tool as we’ve already installed the Open vSwitch and the configuration tool.

Here we’ll see some example to understand that how we can configure.

Single Interface Configuration with Static IP Address

First create a YAML file to save configuration.

sudo nano ovs-interface.yml

And then configure as shown below:

network_config:
- type: interface
 name: eth1
 use_dhcp: false
 use_dhcpv6: false
 addresses:
- ip_netmask: 172.11.101.10/24
routes:
- ip_netmask: 0.0.0.0/0
next_hop: 172.11.101.254
default: true

Result:

It’ll configure the eth1 interface along with the static IP address as 172.11.101/24 and the gateway is 172.11.101.254.

Run the given command to apply the configuration changes.

sudo os-net-config -c ovs-interface.yml

Configure OVS bridge With Single Attached Interface (Port)

First create the file for configuration and then do the changes as given below:

sudo nano ovs-bridge-single-interface.yml

It’ll look like this:

network_config:
- type: ovs_bridge
 name: br-ex 
use_dhcp: false 
use_dhcpv6: false 
addresses:
 - ip_netmask: 172.11.101.10/24
routes:
- ip_netmask: 0.0.0.0/0
next_hop: 172.11.101.254
default: true
members:
-
type: interface
name: eth1

Finally apply the configuration.

os-net-config -c ovs-bridge-single-interface.yml

Configure OVS Bridge on OVS Bond

Follow the below configuration for OVS bridge.

network_config:
- type: 
ovs_bridge 
name: br-ex 
use_dhcp: true 
members: 
- type: ovs_bond 
name: bond1 
members: 
- type: interface
name: em1
- type: interface
name: em2

Apply the changes in a file as done in above step.

Configure Tagged VLAN Interface On Top of OVS Bridge

Here’s the configuration sample.

network_config:
- type: ovs_bridge 
name: br-ctlplane
 use_dhcp: true 
members: 
- type: interface
name: em1
- type: vlan 
vlan_id: 20 
addresses:
- ip_netmask: 192.0.2.1/24

Creating an OVS Bond

You can create OVS bond by doing the changes as given below:

network_config:
- type: ovs_bridge
 name: bond1 
use_dhcp: true
 members: 
- type: interface
name: eno1
- type: interface
name: eno2

Checking OVS Configuration

Once the settings are applied, network config script will be added automatically to /etc/sysconfig/network-scripts/ directory.

ls /etc/sysconfig/network-scripts/

Verify the settings by hitting

ovs-vsctl show

Step 3: Creating KVM Network with OVS

For users who are using Open vSwitch with KVM virutalization, need to define the network that Virtual Machine will use.

Create xml config file.

sudo nano kvm-ovs.xml

Then add the bridge details in the file and save it.

<network>
<name>ovs-bridge </name>
<forward mode='bridge'/>
<bridge name='br-ex'/>
<virtualport type='openvswitch'/>
<network/>

Note:

ovs-bridge: Name of the libvirt network
br-ex: Name of OVS bridge

To define a network from the XML file, without starting it hit

sudo virsh net-define kvm-ovs.xml

If you want to start the inactive network(previously defined) type

sudo virsh net-start ovs-bridge

To start a network when service started, type the following command:

sudo virsh net-autostart ovs-bridge

Verify that autostart flag is turned to yes.

sudo virsh net-list --all

So, this is how you can configure the Open vSwitch on CentOS/RHEL.

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The post Configuring Open vSwitch on CentOS | RHEL | Fedora appeared first on Linux Windows and android Tutorials.

Features of RStudio

• Support Windows, Linux, and macOS
• Syntax highlighting, code completion, and smart indentation
• Integrated support for Git and Subversion
• Execute R code directly from the source editor
• Fastly jump to function definitions
• Manage multiple working directories using projects
• Integrated R help and documentation
• Interactive debugger to diagnose and fix errors quickly
• Extensive package development tools
• Support for interactive graphics with Shiny and ggvis
• Supports authoring HTML, PDF, Word Documents, and slide shows

Step 1: Update Your System

First of all update the system.

sudo yum update

After the update finished run the below command to add the EPEL repositories.

sudo yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
sudo dnf config-manager --set-enabled PowerTools

Step 2: Installing R on CentOS 8

To install the R on CentOS 8 we’ll use the automated script. Just copy and paste the below command in your terminal.

sudo bash -c "$(curl -L https://rstd.io/r-install)"

Output:

You’ll see the similar output.

[sabi@localhost ~]$ sudo bash -c "$(curl -L https://rstd.io/r-install)"
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- 0:00:01 --:--:-- 0
100 11861 100 11861 0 0 3785 0 0:00:03 0:00:03 --:--:-- 482k
Available Versions
4.0.0
3.6.3
3.6.2
3.6.1
3.6.0
3.5.3
3.5.2
3.5.1
3.5.0
3.4.4
3.4.3
3.4.2
3.4.1
3.4.0
3.3.3
3.3.2
3.3.1
3.3.0
3.2.5
3.2.4
3.2.3
3.2.2
3.2.1
3.2.0
3.1.3
3.1.2
3.1.1
3.1.0
3.0.3
3.0.2
3.0.1
3.0.0
Enter version to install: ( for latest)

You can pick the version to install on your system from the above list. To install the latest version just hit the Enter.

Verify the installation by checking the version of R installed.

/opt/R/${R_VERSION}/bin/R --version

Output:

[sabi@localhost ~]$ /opt/R/4.0.0/bin/R --version
R version 4.0.0 (2020-04-24) -- "Arbor Day"
Copyright (C) 2020 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
https://www.gnu.org/licenses/.

Note: ${R_VERSION} is the version of your installed R. So, in my case it would be.

Now, add the path to R binary to your $PATH.

vim ~/.bashrc

export PATH=$PATH:/opt/R/4.0.0/bin/R --version

export PATH=$PATH:/opt/R/4.0.0/bin/

Then source the file & confirm it.

Output:

[sabi@localhost ~]$ source .bashrc
[sabi@localhost ~]$ which R
/opt/R/4.0.0/bin/R
[sabi@localhost ~]$ R --version
R version 4.0.0 (2020-04-24) -- "Arbor Day"
Copyright (C) 2020 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
https://www.gnu.org/licenses/.

Step 3: Installing RStudio on CentOS 8

To install the RStudio on CentOS 8 first, download the package from the official page. We’ll get it through terminal with the help of wget.

sudo yum -y install wget

wget https://download1.rstudio.org/desktop/centos8/x86_64/rstudio-1.3.959-x86_64.rpm

Once the download finished, install it using rpm or yum command.

sudo yum localinstall ./

And press “Y” when prompted.

Wait for the installation to be finished. Now, you can launch it from CLI or Desktop.

[sabi@localhost ~]$ sudo yum localinstall ./rstudio-1.3.959-x86_64.rpm
Last metadata expiration check: 0:33:14 ago on Fri 05 Jun 2020 05:14:10 AM EDT.
Dependencies resolved.
Package Architecture Version Repository Size
Installing:
rstudio x86_64 1.3.959-1 @commandline 143 M
Transaction Summary
Install 1 Package
Total size: 143 M
Installed size: 821 M
Is this ok [y/N]: y

So, you’ve learned that how to Install R & RStudio on CentOS 8.

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The post How To Install R and Rstudio on CentOS 8 appeared first on Linux Windows and android Tutorials.

Step 1: Update Your System

As usual we do, first of all update the system to have the latest packages.

sudo yum -y update

Step 2: Install Dovecot on CentOS 8

As the Dovecot package is available on AppStream yum repo, so simply hit the below command to install it on CentOS*8.

sudo dnf -y install dovecot

Output:

[sabi@localhost ~]$ sudo dnf -y install dovecot
Last metadata expiration check: 0:00:54 ago on Thu 04 Jun 2020 10:29:57 AM EDT.
Dependencies resolved.
Package Arch Version Repository Size
Installing:
dovecot x86_64 1:2.2.36-10.el8 AppStream 4.6 M
Installing dependencies:
clucene-core x86_64 2.3.3.4-31.20130812.e8e3d20git.el8 AppStream 596 k
Transaction Summary
Install 2 Packages
Total download size: 5.2 M
Installed size: 21 M
Downloading Packages:
(1/2): clucene-core-2.3.3.4-31.20130812.e8e3d20 5.1 kB/s | 596 kB 01:56
(2/2): dovecot-2.2.36-10.el8.x86_64.rpm 27 kB/s | 4.6 MB 02:55
Total 30 kB/s | 5.2 MB 02:56
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : clucene-core-2.3.3.4-31.20130812.e8e3d20git.el8.x86_ 1/2
Running scriptlet: dovecot-1:2.2.36-10.el8.x86_64 2/2
Installing : dovecot-1:2.2.36-10.el8.x86_64 2/2
Running scriptlet: dovecot-1:2.2.36-10.el8.x86_64 2/2
Verifying : clucene-core-2.3.3.4-31.20130812.e8e3d20git.el8.x86_ 1/2
Verifying : dovecot-1:2.2.36-10.el8.x86_64 2/2
Installed:
dovecot-1:2.2.36-10.el8.x86_64
clucene-core-2.3.3.4-31.20130812.e8e3d20git.el8.x86_64
Complete!

Step 3: Configuring Dovecot on CentOS8

As you know the installation of Dovecot is not just necessary for its proper working you’ve to configure it to work properly. Here I’ll provide you the fast and reliable configuration so that you face no issue during the installation and configuration of Dovecot.

Edit the /etc/dovecot/dovecot.conf file and un-comment the below line.

sudo nano /etc/dovecot/dovecot.conf
###Uncomment the below lines given.###
protocols = imap pop3 lmtp
listen = *, ::

Then save and close the file.

After it edit the /etc/dovecot/conf.d/10-auth.conf file for authentication purposes & update it to the similar below given.

sudo nano /etc/dovecot/conf.d/10-auth.conf
disable_plaintext_auth = no
auth_mechanisms = plain login

Now, configure the location of the mail server. Make sure to provide the accurate location.

sudo nano /etc/dovecot/conf.d/10-mail.conf

mail_location = maildir:~/Maildir

After it edit the /etc/dovecot/conf.d/10-master.conf file and provide the user name as well as group name of the mail server.

unix_listener /var/spool/postfix/private/auth {
mode = 0666
user = postfix
group = postfix
}

Then finally edit the SSL Configuration file located under /etc/dovecot/conf.d/10-ssl.conf and edit it to use your ownSSL. If you’ve not any SSL certificate it will use it’s own.

ssl = required
ssl_cert =

Step 4: Manage Dovecot Service

To start the Dovecot service on the boot of system hit the below command in your terminal.

sudo systemctl enable dovecot.service

For start, stop and restart hit the below commands respectively.

sudo systemctl start dovecot.service
sudo systemctl stop dovecot.service
sudo systemctl restart dovecot.service

Verify the status of the Dovecot by hitting the below command.

sudo systemctl status dovecot.service

Output:

[sabi@localhost ~]$ sudo systemctl status dovecot.service
● dovecot.service - Dovecot IMAP/POP3 email server
Loaded: loaded (/usr/lib/systemd/system/dovecot.service; disabled; vendor pr>
Active: active (running) since Thu 2020-06-04 10:47:29 EDT; 2s ago
Docs: man:dovecot(1)
http://wiki2.dovecot.org/
Process: 36951 ExecStart=/usr/sbin/dovecot (code=exited, status=0/SUCCESS)
Process: 36942 ExecStartPre=/usr/libexec/dovecot/prestartscript (code=exited,>
Main PID: 36952 (dovecot)
Tasks: 4 (limit: 4884)
Memory: 11.1M
CGroup: /system.slice/dovecot.service
├─36952 /usr/sbin/dovecot
├─36959 dovecot/anvil
├─36960 dovecot/log
└─36962 dovecot/config
Jun 04 10:47:29 localhost.localdomain systemd[1]: Starting Dovecot IMAP/POP3 em>
Jun 04 10:47:29 localhost.localdomain dovecot[36951]: Warning: Corrected permis>
Jun 04 10:47:29 localhost.localdomain dovecot[36951]: master: Warning: Correcte>
Jun 04 10:47:29 localhost.localdomain systemd[1]: Started Dovecot IMAP/POP3 ema>
Jun 04 10:47:29 localhost.localdomain dovecot[36952]: master: Dovecot v2.2.36 (>

Step 5: Testing Configuration

To test the configuration create a user on your system and install the muatt to connect to the mailbox using imaps protocol.

sudo dnf install mutt

After it connect to the mail box by hitting

mutt -f imaps://sabi@localhost

Note: Replace the username “sabi” with your own username.

Accept the certificate when prompted. And provide your credentials to see the emails of your account.

Step 6: Allow Firewall Access

To access the server from remote machine, don’t forget to allow the firewall.

Here are the ports used by IMAP,IMAPS,POP3 and POP3S.

• IMAP – 143
• IMAPS – 993
• POP3 – 110
• POP3S – 995

To add firewall rules hit the below commands.

sudo firewall-cmd --add-service={pop3,imap} --permanent
sudo firewall-cmd --add-service={pop3s,imaps} --permanent

And then reload the changes to take effect.

sudo firewall-cmd --reload

So, this is how you can install dovecot on CentOS 8 and configure it.

The post How to Install Dovecot on CentOS 8 appeared first on Linux Windows and android Tutorials.