Red Hat RHCE 8 (EX294) Cert Guide, 1st edition

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