Red Hat Enterprise Linux Automation with Ansible
In this course, the main computer system used for hands-on learning activities is workstation.
Four other machines are also used by students for these activities: servera, serverb, serverc, and serverd.
All these five systems are in the lab.example.com DNS domain.
All student computer systems have a standard user account, student, which has the password student. The root password on all student systems is redhat.
Table 1. Classroom Machines
| Machine name | IP addresses | Role |
|---|---|---|
bastion.lab.example.com
|
172.25.250.254
| Gateway system to connect student private network to classroom server (must always be running) |
utility.lab.example.com
|
172.25.250.8
| System with utility services required for the classroom |
workstation.lab.example.com
|
172.25.250.9
| Graphical workstation used for system administration |
servera.lab.example.com
|
172.25.250.10
| Host managed with Ansible |
serverb.lab.example.com
|
172.25.250.11
| Host managed with Ansible |
serverc.lab.example.com
|
172.25.250.12
| Host managed with Ansible |
serverd.lab.example.com
|
172.25.250.13
| Host managed with Ansible |
The primary function of bastion is that it acts as a router between the network that connects the student machines and the classroom network. If bastion is down, other student machines will only be able to access systems on the individual student network.
Several systems in the classroom provide supporting services. Two servers, content.example.com and materials.example.com, are sources for software and lab materials used in hands-on activities. Information on how to use these servers is provided in the instructions for those activities. These are provided by the classroom.example.com virtual machine. Both classroom and bastion should always be running for proper use of the lab environment.
You are assigned remote computers in a Red Hat Online Learning (ROLE) classroom. Self-paced courses are accessed through a web application that is hosted at . Log in to this site with your Red Hat Customer Portal user credentials.
The virtual machines in your classroom environment are controlled through web page interface controls. The state of each classroom virtual machine is displayed on the tab.
Table 2. Machine States
| Virtual Machine State | Description |
|---|---|
| building | The virtual machine is being created. |
| active | The virtual machine is running and available. If it just started, it still might be starting services. |
| stopped | The virtual machine is completely shut down. On starting, the virtual machine boots into the same state it was in before shutdown. The disk state is preserved. |
Table 3. Classroom Actions
| Button or Action | Description |
|---|---|
| Create the ROLE classroom. Creates and starts all the virtual machines needed for this classroom. Creation can take several minutes to complete. | |
| The ROLE classroom virtual machines are being created. Creates and starts all the virtual machines that are needed for this classroom. Creation can take several minutes to complete. | |
| Delete the ROLE classroom. Destroys all virtual machines in the classroom. All saved work on those systems' disks is lost. | |
| Start all virtual machines in the classroom. | |
| All virtual machines in the classroom are starting. | |
| Stop all virtual machines in the classroom. |
Table 4. Machine Actions
| Button or Action | Description |
|---|---|
Connect to the system console of the virtual machine in a new browser tab.
You can log in directly to the virtual machine and run commands, when required.
Normally, log in to the workstation virtual machine only, and from there, use ssh to connect to the other virtual machines. | |
| → | Start (power on) the virtual machine. |
| → | Gracefully shut down the virtual machine, preserving disk contents. |
| → | Forcefully shut down the virtual machine, while still preserving disk contents. This is equivalent to removing the power from a physical machine. |
| → | Forcefully shut down the virtual machine and reset associated storage to its initial state. All saved work on that system's disks is lost. |
At the start of an exercise, if instructed to reset a single virtual machine node, click → for only that specific virtual machine.
At the start of an exercise, if instructed to reset all virtual machines, click → on every virtual machine in the list.
If you want to return the classroom environment to its original state at the start of the course, then click to remove the entire classroom environment. After the lab has been deleted, then click to provision a new set of classroom systems.
Warning
The operation cannot be undone. All completed work in the classroom environment is lost.
The Red Hat Online Learning enrollment entitles you to a set allotment of computer time. To help conserve your allotted time, the ROLE classroom uses timers, which shut down or delete the classroom environment when the appropriate timer expires.
To adjust the timers, locate the two buttons at the bottom of the course management page. Click the auto-stop button to add another hour to the auto-stop timer. Click the auto-destroy button to add another day to the auto-destroy timer. Auto-stop has a maximum of 11 hours, and auto-destroy has a maximum of 14 days. Be careful to keep the timers set while you are working, so that your environment is not unexpectedly shut down. Be careful not to set the timers unnecessarily high, which could waste your subscription time allotment.
You might see four types of lab activities in this course:
A guided exercise is a hands-on practice exercise that follows a presentation section. It takes you step-by-step through a procedure to perform.
A quiz is typically used when checking knowledge-based learning, or when a hands-on activity is impractical for some other reason.
An end-of-chapter lab is a gradable hands-on activity to help you check your learning. You are provided with a set of high-level steps to perform, based on the guided exercises in that chapter, but the steps do not walk you through every command. You are also given a solution that provides a step-by-step walk-through.
A comprehensive review lab is used at the end of the course. It is also a gradable hands-on activity, but it covers content from throughout the entire course. You are provided with a specification that details what you need to accomplish in the activity, but not the specific steps to do so. Again, you are given a solution that provides a step-by-step walk-through that meets the specification.
To prepare your lab environment at the start of each hands-on activity, run the lab start command with an activity name specified by the activity's instructions.
Likewise, at the end of each hands-on activity, run the lab finish command with that same activity name to clean up after the activity.
Each hands-on activity has a unique name within a course.
The syntax for running an exercise script is as follows:
[student@workstation ~]$ lab action exerciseThe action is a choice of start, grade, or finish.
All exercises support start and finish actions.
Only end-of-chapter labs and comprehensive review labs support the grade action.
- start
The
startaction verifies the required resources to begin an exercise. It might include configuring settings, creating resources, checking prerequisite services, and verifying necessary outcomes from previous exercises. You can take an exercise at any time, even without taking preceding exercises.- grade
For gradable activities, the
gradeaction directs thelabcommand to evaluate your work, and displays a list of grading criteria with aPASSorFAILstatus for each. To achieve aPASSstatus for all criteria, fix any failures and rerun thegradeaction.- finish
The
finishaction cleans up resources configured during the exercise. You can take an exercise as many times as you want.
The lab command supports tab completion.
For example, to list all exercises that you can start, enter lab start and then press the Tab key twice.
