development

Objective

Our objective is to ensure that updating the operating system will run smoothly and without errors.

Operating System and Software Versions

• Operating system: Red Hat Enterprise Linux 6+

Requirements

Privileged access to the systems

Difficulty

EASY

Conventions

• # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
• $ – given linux commands to be executed as a regular non-privileged user

Introduction

Keeping the system up to date is an every day task for a sysadmin, as well as a desktop user. By applying the latest (stable) available software on the system we can take advantage of the latest features, and will be more protected from security issues and hopefully suffer less from bugs. To update the system you will need configured yum repositories that act as the source of the updated software.

If you sit next to the machine that is running the operating system to be updated, you can easily act if something goes wrong during update, like checking the output on the terminal, or boot to a live system if the upgraded one does not return from reboot – but this is not always the case. Think of a datacenter with hundreds or thousands of (virtual) machines, or simply a physical PC that you have to upgrade remotely.

There are simple steps we can perform to prepare the system for upgrade, and possibly clear any problem that would endanger a successful update.

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Objective

Our goal is to build rpm packages with custom content, unifying scripts across any number of systems, including versioning, deployment and undeployment.

Operating System and Software Versions

• Operating system: Red Hat Enterprise Linux 7.5
• Software: rpm-build 4.11.3+

Requirements

Privileged access to the system for install, normal access for build.

Difficulty

MEDIUM

Conventions

• # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
• $ – given linux commands to be executed as a regular non-privileged user

Introduction

One of the core feature of any Linux system is that they are built for automation. If a task may need to be executed more than one time – even with some part of it changing on next run – a sysadmin is provided with countless tools to automate it, from simple shell scripts run by hand on demand (thus eliminating typo errors, or only save some keyboard hits) to complex scripted systems where tasks run from cron at a specified time, interacting with each other, working with the result of another script, maybe controlled by a central management system etc.

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Objective

Our objective is to set up access to internal and remote yum repositories while some of them are behind proxy servers.

Operating System and Software Versions

• Operating system: Red Hat Enterprise Linux 7.5

Requirements

Privileged access to the system

Difficulty

EASY

Conventions

• # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
• $ – given linux commands to be executed as a regular non-privileged user

Introduction

In a corporate environment it is common to limit Internet access – both for security and accountability. This is often accomplished by using proxy servers that enable access to the Internet after some sort of authentication, while inspect and log all traffic passing trough them. This way the company can, for example find the employee who downloaded the virus that wreak havoc within the corporate system (or at least the employee who’s credentials where stolen to do so), or filter the traffic, preventing access to well-known harmful sites to protect employee equipment.

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