Disabling proxy for internal repository

How to add repositories to Red Hat Linux with and without a proxy

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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Tomcat providing the examples application

How to set up Apache webserver proxy in front of Apache Tomcat on Red Hat Linux

Objective

Our objective is to setup Apache httpd to work as a proxy in front of the Apache Tomcat application container.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5
  • Software: Apache httpd, Apache Tomcat

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

Using Apache httpd as a proxy to an Apache Tomcat application container is a common setup. It comes with many use cases, the most trivial is serving static content from httpd, while providing services implementing heavy business logic from an application written in Java that resides in the Tomcat container.

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Summary of interactive yum update

Preparing for applying updates on Red Hat Linux

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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FreeIPA login page

How to install and configure FreeIPA on Red Hat Linux

Objective

Our objective is to install and configure a standalone FreeIPA server on Red Hat Enterprise Linux.

Operating System and Software Versions

  • Operating System: Red Hat Enterprise Linux 7.5
  • Software: FreeIPA 4.5.4-10

Requirements

Privileged access to the target server, available software repository.

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

FreeIPA is mainly a directory service, where you can store information about your users, and their rights regarding login, become root, or just run a specific command as root on your systems that are joined your FreeIPA domain, and many more. Although this is the main feature of the service, there are optional components that can be very useful, like DNS and PKI – this makes FreeIPA an essential infrastructural part of a Linux-based system. It has a nice web-based GUI, and powerful command line interface.

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Solving dependencies with rpm

Working with package dependencies on Red Hat Linux

Objective

Our goal is to get used to the tools available to find out information about package dependencies on an RPM based system.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5
  • Software: rpm 4.11, yum 3.4.3

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

RPM, which stands for Red Hat Package Manager, is a well-known and mature package manager used by all Red Hat flavor distributions, as well as SuSE. With RPM the packager can define relations between packages, and even with versions of packages – for example, an Apache Tomcat server needs proper Java environment present to be able to run.

On the other hand, to install a Java environment, you don’t need a Tomcat server – you may decide to run some different Java based application, maybe one written by yourself started by hand when needed to do it’s job. In other words, the Tomcat server depends on Java.

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