Learning the Essentials of CentOS Enterprise Linux 7 Administration

Course Overview
Hi everyone and welcome. My name is Andrew Mallett and I'd like to introduce you to my course, Learning the Essentials of CentOS Enterprise Linux 7 Administration. Now, I'm the owner of The Urban Penguin within the UK and I train and consult in Linux and have done for many years now. I work both as a system administrator and a dabbling developer. The use of Linux, as you're probably already aware, is on the increase and you don't want to be left behind. So, no matter if you are starting out your career in system administration or you just want to complement other skillsets that you already have, expanding your CV, this course is going to get you started and up and running with CentOS 7. Very quickly and effectively you will soon understand the essentials of managing an enterprise Linux environment. Some of the major topics that we're going to cover include Linux permissions, the chmods and the chowns of the world. We'll be looking at running as the root user or the administrator and we'll using the command sudo or SU. We'll be looking at running commands across many systems at the same time as well as looking at how we can run commands both locally and remotely across our enterprise Linux systems. By the end of this Pluralsight course, you will know how to install and run commands on CentOS 7-based systems. Not wanting to stop here, you will be able to use regular expressions to search files and you'll be able to edit files either using VIM or dynamically using the Stream Editor Sed. You will be the Linux maestro you have always imagined. Before beginning this course, you should be familiar with the concepts of system administration and want to achieve Linux system administration as your goal.

Reading Files
I certainly hope you're ready to be reading some files with me. My name is Andrew Mallett, and I welcome you to this module from Pluralsight, Reading Files. And when we take a look at the objectives we'll be covering within this molecule, we'll be looking at analyzing text using regular expressions; we'll be looking at comparing text files; comparing binary files; manipulating file content programmatically, and we'll be using sed to do that; and we'll be using the find command to search for files. We'll also be using some our very basic tools for reading files, such as cat and heads and tails. We're going to be filling this module with some demonstrations and we're going to start off, as we say, working through some of those basic tools such as cat and heads and tails, reading from files. Once we're through with that, we can get straight into using regular expressions and searching files for certain text. We'll then be editing files using the sed command line editor. We'll be looking at how we can compare files, and we'll be looking at how we can use checksums to compare binary files. So when you're ready, we're going to make a start by reading from files.

Archiving Files
Hello and welcome to this presentation from Pluralsight. My name, of course, is Andrew Mallett, and I'm here as your instructor to help guide you through this module, archiving files. What I mean by that, we could be looking at creating file backups and looking at imaging disks. The objectives that we look at specifically within this module are archiving, compressing, unpacking, so extracting the archives, and decompressing files, as well as performing disk image management. As always, to help you learn we're going to be packing these modules full of demonstrations. And these demonstrations are going to include using the tar command to create and expand our archives. We'll be looking at some of our compression utilities, some of which can be used with tar as well. But gzip, bzip2, and unzipping with gunzip and bunzip2. We also have another archive, the cpio archiving utility, and we'll be looking at using that. And we'll be using the dd command so we can look at creating and imaging with disk duplicator command. Now to kick things straight off we're going to begin by looking at the tar command, the tape archive command, but don't believe too much about tapes. Don't worry, we can write to tape devices, but very often we are backing up these files through to disk devices.

Accessing the Root Account
Hello and welcome to this presentation from Pluralsight. My name is Andrew Mallett and I'm here as your instructor to help guide you through the module, Accessing the Root Account. Now, we're going to be looking at the objective here, how we can manage access through to our root user account in Linux or our administrator. Now, of course, even though we're only looking at a single objective that we're trying to meet, there are many different ways that we can gain access as our root user, so we'll be looking at a few demonstrations along the way to support your learning. And these demonstrations are going to include using the su or the substitute user command. With this, if we needed to gain root access, we would have to know the root user's password. So, this is one method but is no necessarily the best or certainly not the only method. Another way we can do is using the sudo command and with this we have delegated rights of what each individual user or group is allowed to do through sudo defined within our /etc/sudoers file. Finally, we'll be going through and taking a look at how we can restrict root access via SSH or remote access. If we have a public-facing machine, we don't necessarily want everyone trying to log onto that machine as a root user, so we'll see how we can disable a root access via SSH. So, now we know what we're going to cover, let's look at our first set of demonstrations.

Accessing Servers with SSH
I'm sure it won't have escaped your notice that throughout this course, I've been accessing server1 through ssh through the putty client on Windows, so the secure shell environment, and this certainly is a secure way of accessing the server remotely. Everything is encrypted with public key, private key mechanisms. We're going to take a look within this module, a little more detail at how we use ssh. Specifically, though, we're looking at the objectives: accessing remote systems securely using the command line, as well as transferring files securely via the network. So when you're ready, we're going to begin. And of course we're going to have lots of demonstrations. We'll be taking a look at how we can configure the Linux ssh client. We'll be looking at how we can use public key authentication rather than just passwords, and we're looking at how we can copy files with SCP. We're going to need to have set this module up and configured everything within this module to be able to go on to the next module where we're going to be looking at running commands across multiple hosts. Now to get the show started, we're going to start with a little bit more detail looking at the ssh client.