Getting Started With CentOS 7

This article is intended for Hostwinds clients who have chosen to install CentOS 7 to begin configuring and customizing the server using the command-line interface. We highly recommend taking a snapshot backup before making any modifications in case you need to restore it at any time. Below are some basic configurations you can view and configure to fit your needs. This article is meant to offer our Unmanaged clients some basic commands and information to help you get started with a clean install of CentOS 7 on your Instance.

Any commands that are preceded with a # are suggested to be using root user access. Commands preceded with a $  indicate that a regular user can perform these tasks.

Basic System Configuration

Date and Time

Displaying Current Date and Time using one of the following commands

date

timedatectl

Changing Local Time

timedatectl list-timezones

timedatectl set-timezone [time_zone]

Change [time_zone]  to the time zone you prefer to use for your local time from an option on the list-timezones  results

System Locale

List all available locales

localectl list-locales

Show current locale setting

localectl status

Set or change system locale

localectl set-locale LANG=[locale]

Replace [locale]  above with the locale setting of your choice

Manage Software using Yum

List all enabled repositories

yum repolist

Search for a package using yum

yum search [string]

Replace [string]  above with what you are searching for

Install a package

yum install [package_name]

Replace [package_name]  above with the package name

Update all packages and their dependencies

yum update

Enable service on boot

systemctl enable [service]

Disable a service on boot

systemctl disable [service]

Replace [service]  with the name of the service.

Install ConfigServer Security & Firewall (CSF) or Firewalld

Install CSF

If you decide to use CSF instead of firewalld, here are the installation instructions:

cd /usr/src

rm -fv csf.tgz

wget https://download.configserver.com/csf.tgz

tar -xzf csf.tgz

cd csf

sh install.sh

Enable csf and lfd using your favorite text editor to be started and taken out of testing. Just open the /etc/csf/csf.conf file and replace TESTING = "1"  with TESTING = "0" and save this file.

Next, start csf:

systemctl start csf

systemctl start lfd

Now, enable csf and lfd to begin on startup:

systemctl enable csf

systemctl enable lfd

You can then configure csf and lfd by reading the documentation and configuration files in /etc/csf/csf.conf and /etc/csf/readme.txt directly or through the csf User Interface.

Install Firewalld

If you prefer to use firewalld with SELinux and not csf, the instructions are below:

yum install firewalld

Start Firewalld and begin on system startup

systemctl enable firewalld

Enable SELinux

Set SELinux to enforce permanently so that SELinux policies are enforced, modify the /etc/selinux/config configuration file using your favorite text editor, and set this to enforce as seen below and save these changes.

Generate SSH Keys

If you have not already generated a key when creating your instance, or if you would like to add another key pair, you can do so with the help of the guide to Create a Strong SSH Key in Linux

Manage User Accounts

Create a new user

# useradd [options] [user_name]

Use useradd –help to see the options to replace in [options]  above and replace [user_name]  with the username you would like to create.

Assign a password to a user

# passwd [user_name]

Replace [user_name]  above with the username.

Add a User to a Group

# usermod -a -G [group_name] [user_name]

Replace [group_name]  with the group name you want to assign the user to and the [user_name]  with the desired user name you would like to assign to a group.

If you are having any trouble with our Managed Services or have any questions, please let us know to help you.