Red Hat RHCE 8 (EX294) Cert Guide

Introduction xxii
Part I: Introduction to Ansible
Chapter 1 Understanding Configuration Management 3
"Do I Know This Already?" Quiz 3
Foundation Topics 6
Understanding Automation 6
What Is Automation? 6
Understanding the DevOps Way of Working 7
Understanding Infrastructure as Code 8
Other Automation Solutions 8
Understanding Ansible Essential Components 9
Ansible Is Python 9
Ansible Architecture 9
Understanding Ansible Tower 10
Understanding the Ansible Way 11
Understanding Ansible Use Cases 11
Using Ansible for Configuration Management 11
Using Ansible for Provisioning 12
Using Ansible for Continuous Delivery 12
Summary 12
Exam Preparation Tasks 12
Review All Key Topics 12
Define Key Terms 13
Chapter 2 Installing Ansible 15
"Do I Know This Already?" Quiz 15
Foundation Topics 18
Understanding an Ansible Environment 18
Understanding Controller Host Requirements 20
Understanding Installation Methods 20
Installing Ansible on RHEL 8 21
Installing Ansible on CentOS 8 21
Using python-pip to Install Ansible 21
Configuring Managed Hosts 22
Configuring the Ansible User 23
Setting Up SSH for the Ansible User 23
Configuring sudo for the Ansible User 25
Summary 26
Exam Preparation Tasks 26
Review All Key Topics 26
Memory Tables 27
Define Key Terms 27
Review Questions 27
End-of-Chapter Lab 28
Chapter 3 Setting Up an Ansible Managed Environment 31
"Do I Know This Already?" Quiz 31
Foundation Topics 34
Understanding Projects 34
Configuring Static Inventory 35
Listing Hosts 35
Inventory Host Groups 36
Using Inventory in Commands 37
Specifying Host Variables 38
Working with Dynamic Inventory 39
Working with Community-Provided Dynamic Inventory Scripts 39
Writing Your Own Inventory Scripts 40
Using Multiple Inventory Files 42
Managing Settings in ansible.cfg 42
Summary 44
Exam Preparation Tasks 44
Review All Key Topics 44
Memory Tables 44
Define Key Terms 44
Review Questions 45
End-of-Chapter Lab 45
Chapter 4 Using Ad Hoc Commands 47
"Do I Know This Already?" Quiz 47
Foundation Topics 50
Understanding Ad Hoc Commands 50
Working with Modules 53
Exploring Essential Modules 54
command 54
shell 55
raw 55
copy 55
yum 56
service 56
ping 56
Browsing Available Modules 58
Consulting Module Documentation 58
Using ansible-doc 58
Using https://docs.ansible.com 62
Running Ad Hoc Commands from Shell Scripts 64
Summary 66
Exam Preparation Tasks 66
Review All Key Topics 66
Memory Tables 66
Define Key Terms 66
Review Questions 67
End-of-Chapter Lab 67
Chapter 5 Getting Started with Playbooks 69
"Do I Know This Already?" Quiz 69
Foundation Topics 72
Exploring Your First Playbook 72
From Ad Hoc Commands to Playbook 72
Playbook Elements 73
Running the Playbook 74
Undoing Playbook Modifications 75
Working with YAML 77
Indentation 77
Using Key-Value Pairs 78
Understanding YAML Lists 79
Using YAML Strings 79
Verifying Syntax 80
Performing a Playbook Dry Run 81
Managing Multiplay Playbooks 83
Multiplay Playbook Considerations 83
Multiplay Playbook Example 84
Increasing Output Verbosity 86
Summary 92
Exam Preparation Tasks 92
Review All Key Topics 93
Memory Tables 93
Define Key Terms 93
Review Questions 93
End-of-Chapter Lab 94
Chapter 6 Working with Variables and Facts 97
"Do I Know This Already?" Quiz 97
Foundation Topics 100
Understanding the Use of Variables in Ansible Playbooks 100
Working with Ansible Facts 101
Gathering Facts 102
Understanding How Facts Are Displayed 104
Managing Fact Gathering 108
Working with Custom Facts 109
Working with Variables 111
Defining Variables 112
Using Include Files 112
Managing Host and Group Variables 113
Using Multivalued Variables 115
Working with Magic Variables 117
Understanding Variable Precedence 119
Using Vault to Manage Sensitive Values 119
Understanding Vault 119
Managing Encrypted Files 120
Using Vault in Playbooks 120
Managing Files with Sensitive Variables 121
Capturing Command Output Using register 122
Summary 125
Exam Preparation Tasks 125
Review All Key Topics 125
Memory Tables 125
Define Key Terms 126
Review Questions 126
End-of-Chapter Labs 126
Part II: Common Ansible Management Tasks
Chapter 7 Using Task Control 131
"Do I Know This Already?" Quiz 131
Foundation Topics 134
Using Loops and Items 134
Working with Loops 134
Using Loops on Variables 135
Using Loops on Multivalued Variables 136
Understanding with_items 137
Using when to Run Tasks Conditionally 139
Working with when 139
Using Conditional Test Statements 141
Testing Multiple Conditions 144
Combining loop and when 145
Combining loop and register 147
Using Handlers 149
Working with Handlers 149
Understanding Handler Execution and Exceptions 154
Dealing with Failures 156
Understanding Task Execution 156
Managing Task Errors 156
Specifying Task Failure Conditions 158
Managing Changed Status 161
Using Blocks 163
Using Blocks with rescue and always Statements 164
Summary 169
Exam Preparation Tasks 169
Review All Key Topics 169
Memory Tables 170
Define Key Terms 170
Review Questions 170
End-of-Chapter Lab 171
Chapter 8 Deploying Files 173
"Do I Know This Already?" Quiz 173
Foundation Topics 176
Using Modules to Manipulate Files 176
File Module Manipulation Overview 176
Managing File Attributes 176
Managing File Contents 180
Creating and Removing Files 182
Moving Files Around 183
Managing SELinux Properties 187
Managing SELinux File Context 188
Applying Generic SELinux Management Tasks 189
Using Jinja2 Templates 194
Working with Simple Templates 194
Applying Control Structures in Jinja2 Using for 197
Using Conditional Statements with if 198
Using Filters 198
Summary 200
Exam Preparation Tasks 200
Review All Key Topics 200
Memory Tables 201
Define Key Terms 201
Review Questions 201
Exercise Answers 201
End-of-Chapter Labs 202
Chapter 9 Using Ansible Roles 205
"Do I Know This Already?" Quiz 205
Foundation Topics 208
Using Ansible Roles 208
Understanding Ansible Roles 208
Understanding Role Location 209
Using Roles from Playbooks 210
Creating Custom Roles 210
Managing Role Dependencies 213
Understanding File Organization Best Practices 213
Using Ansible Galaxy Roles 214
Working with Galaxy 215
Using the ansible-galaxy Command 216
Managing Ansible Galaxy Roles 218
Using RHEL System Roles 219
Understanding RHEL System Roles 220
Installing RHEL System Roles 220
Using the RHEL SELinux System Role 221
Using the RHEL TimeSync System Role 224
Summary 225
Exam Preparation Tasks 225
Review All Key Topics 226
Memory Tables 226
Define Key Terms 226
Review Questions 226
End-of-Chapter Labs 227
Chapter 10 Using Ansible in Large Environments 229
"Do I Know This Already?" Quiz 229
Foundation Topics 232
Advanced Inventory Usage 232
Working with Host Name Patterns 232
Configuring Dynamic Inventory 233
Using the ansible-inventory Command 235
Working with Multiple Inventory Files 236
Optimizing Ansible Processing 237
Managing Parallel Task Execution 237
Managing Serial Task Execution 238
Including and Importing Files 239
Importing Playbooks 240
Importing and Including Task Files 242
Using Variables When Importing and Including Files 243
Summary 247
Exam Preparation Tasks 247
Review All Key Topics 248
Define Key Terms 248
Review Questions 248
End-of-Chapter Lab 249
Chapter 11 Troubleshooting Ansible 251
"Do I Know this Already?" Quiz 251
Foundation Topics 254
Managing Ansible Errors and Logs 254
Using Check Mode 254
Understanding Output 256
Optimizing Command Output Error Formatting 259
Logging to Files 259
Running Task by Task 260
Using Modules for Troubleshooting and Testing 263
Using the Debug Module 263
Using the uri Module 263
Using the stat Module 265
Using the assert Module 268
Using Tags 271
Troubleshooting Common Scenarios 275
Analyzing Connectivity Issues 275
Analyzing Authentication Issues 276
Summary 277
Exam Preparation Tasks 277
Review All Key Topics 278
Memory Tables 278
Define Key Terms 278
Review Questions 278
End-of-Chapter Lab 279
Part III: Managing Systems with Ansible
Chapter 12 Managing Software with Ansible 281
"Do I Know This Already?" Quiz 281
Foundation Topics 284
Using Modules to Manage Packages 284
Configuring Repository Access 284
Managing Software with yum 285
Managing Package Facts 287
Using Modules to Manage Repositories and Subscriptions 289
Setting Up Repositories 290
Managing GPG Keys 291
Managing RHEL Subscriptions 292
Implementing a Playbook to Manage Software 297
Summary 301
Exam Preparation Tasks 302
Review All Key Topics 302
Memory Tables 302
Define Key Terms 302
Review Questions 302
End-of-Chapter Labs 303
Chapter 13 Managing Users 305
"Do I Know This Already?" Quiz 305
Foundation Topics 308
Using Ansible Modules to Manage Users and Groups 308
Modules Overview 308
Managing Users and Groups 308
Managing sudo 309
Managing SSH Connections 313
Understanding SSH Connection Management Requirements 313
Using the Lookup Plug-in 314
Setting Up SSH User Keys 314
Managing Encrypted Passwords 319
Understanding Encrypted Passwords 319
Generating Encrypted Passwords 319
Using an Alternative Approach 321
Managing Users Advanced Scenario Exercise 323
Summary 329
Exam Preparation Tasks 330
Review All Key Topics 330
Memory Tables 330
Define Key Terms 330
Review Questions 330
End-of-Chapter Lab 331
Chapter 14 Managing Services and the Boot Process 333
"Do I Know This Already?" Quiz 333
Foundation Topics 336
Managing Services 336
Managing Systemd Services 336
Managing cron Jobs 337
Managing at Jobs 338
Managing the Boot Process 341
Managing Systemd Targets 341
Rebooting Managed Hosts 342
Managing the Boot Process and Services Advanced Exercise 344
Summary 346
Exam Preparation Tasks 346
Review All Key Topics 346
Memory Tables 347
Define Key Terms 347
Review Questions 347
End-of-Chapter Lab 348
Chapter 15 Managing Storage 351
"Do I Know This Already?" Quiz 351
Foundation Topics 354
Discovering Storage-Related Facts 354
Using Storage-Related Facts 354
Using Storage-Related Facts in Conditional Statements 357
Managing Partitions and LVM 364
Creating Partitions 364
Managing Volume Groups and LVM Logical Volumes 366
Creating and Mounting File Systems 367
Configuring Swap Space 368
Configuring Storage Advanced Exercise 371
Summary 379
Exam Preparation Tasks 380
Review All Key Topics 380
Memory Tables 380
Define Key Terms 380
Review Questions 380
End-of-Chapter Lab 381
Chapter 16 Final Preparation 383
Generic Tips 383
Verifying Your Readiness 383
Registering for the Exam 384
On Exam Day 384
During the Exam 385
The Nondisclosure Agreement 386
Part IV: Practice Exams
Practice Exam A 387
Practice Exam B 391
Part V: Appendixes
Appendix A Answers to the "Do I Know This Already?" Quizzes and Review Questions 395
Appendix B Getting Started with Ansible Tower 415
Appendix C Red Hat RHCE 8 (EX294) Cert Guide Exam Updates 431
Glossary 433

Online Elements:
Practice Exam C
Practice Exam D
Appendix D Memory Tables
Appendix E Memory Tables Answer Key
Appendix F Study Planner
Glossary

9780136872436 TOC 8/25/2020