Description
Book SynopsisAt the impressionable age of 14, William Bo Rothwell crossed paths with a TRS-80 Micro Computer System (affectionately known as a Trash 80). Soon after the adults responsible for Bo made the mistake of leaving him alone with the TSR-80, he dismantled it and held his first computer class, showing his friends what made this computer thing work.
Since that experience, Bo's passion for understanding how computers work and sharing this knowledge with others has resulted in a rewarding career in IT training. His experience includes Linux, Unix, IT security, DevOps, cloud technologies, and programming languages such as Perl, Python, Tcl, and BASH. He is the founder and lead instructor of One Course Source, an IT training organization.
Table of Contents Introduction. . . . . . . . . . . . xxiv
Part I: System Management
CHAPTER 1: Linux Fundamentals. . . . . . . . . . . 1
Filesystem Hierarchy Standard (FHS).. . . . . . . 1
Basic Boot Process.. . . . . . . . . . 3
Kernel Panic. . . . . . . . . . . 10
Device Types in /dev.. . . . . . . . . 10
Basic Package Compilation from Source.. . . . . . 13
./configure.. . . . . . . . . . 13
make.. . . . . . . . . . . 15
make install.. . . . . . . . . . 16
Storage Concepts.. . . . . . . . . . 16
Listing Hardware Information.. . . . . . . . 22
CHAPTER 2: Manage Files and Directories.. . . . . . . . . 27
File Editing.. . . . . . . . . . . 27
File Compression, Archiving, and Backup. . . . . . 36
File Metadata.. . . . . . . . . . . 41
Soft and Hard Links.. . . . . . . . . 43
Copying Files Between Systems.. . . . . . . 46
File and Directory Operations.. . . . . . . . 49
CHAPTER 3: Configure and Manage Storage Using the Appropriate Tools.. . . 57
Disk Partitioning.. . . . . . . . . . 57
Mounting Local and Remote Devices.. . . . . . 61
Filesystem Management. . . . . . . . . 66
Monitoring Storage Space and Disk Usage. . . . . . 70
Creating and Modifying Volumes Using Logical Volume Manager (LVM).. . . . . . . . . . 71
Inspecting RAID Implementations.. . . . . . . 75
Storage Area Network (SAN)/Network-Attached Storage (NAS). . 78
Storage Hardware.. . . . . . . . . . 82
CHAPTER 4: Configure and Use the Appropriate Processes and Services.. . . 85
System Services. . . . . . . . . . 85
Scheduling Services. . . . . . . . . . 90
Process Management. . . . . . . . . 97
CHAPTER 5: Use the Appropriate Networking Tools or Configuration Files. . . 113
Interface Management.. . . . . . . . . 113
Name Resolution.. . . . . . . . . . 122
Network Monitoring.. . . . . . . . . 127
Remote Networking Tools.. . . . . . . . 132
CHAPTER 6: Build and Install Software. . . . . . . . . 139
Package Management.. . . . . . . . . 139
Sandboxed Applications.. . . . . . . . . 149
System Updates.. . . . . . . . . . 150
Part II: Security
CHAPTER 7: Manage Software Configurations.. . . . . . . . 155
Updating Configuration Files.. . . . . . . . 155
Configure Kernel Options.. . . . . . . . 158
Configure Common System Services.. . . . . . . 165
Localization.. . . . . . . . . . . 172
CHAPTER 8: Security Best Practices in a Linux Environment.. . . . . 177
Managing Public Key Infrastructure (PKI) Certificates.. . . 177
Certificate Use Cases. . . . . . . . . 181
Authentication.. . . . . . . . . . 181
Linux Hardening.. . . . . . . . . . 188
CHAPTER 9: Implement Identity Management. . . . . . . . 201
Account Creation and Deletion. . . . . . . . 201
.bashrc. . . . . . . . . . . 212
Account Management.. . . . . . . . . 212
CHAPTER 10: Implement and Configure Firewalls.. . . . . . . . 219
Firewall Use Cases.. . . . . . . . . . 219
Common Firewall Technologies.. . . . . . . 221
Key Firewall Features.. . . . . . . . . 223
CHAPTER 11: Configure and Execute Remote Connectivity for System Management.. 227
SSH.. . . . . . . . . . . . 227
Executing Commands as Another User.. . . . . . 235
CHAPTER 12: Apply the Appropriate Access Controls. . . . . . . 241
File Permissions.. . . . . . . . . . 241
Security-Enhanced Linux (SELinux).. . . . . . . 243
AppArmor.. . . . . . . . . . . 247
Command-Line Utilities.. . . . . . . . . 250
Part III: Scripting, Containers, and Automation
CHAPTER 13: Create Simple Shell Scripts to Automate Common Tasks. . . . 265
Shell Script Elements.. . . . . . . . . 265
Common Script Utilities.. . . . . . . . . 286
Environment Variables. . . . . . . . . 298
Relative and Absolute Paths.. . . . . . . . 302
CHAPTER 14: Perform Basic Container Operations. . . . . . . 305
Container Management.. . . . . . . . . 305
Container Image Operations.. . . . . . . . 312
CHAPTER 15: Perform Basic Version Control Using Git.. . . . . . . 317
Introduction to Version Control and Git.. . . . . . 317
clone.. . . . . . . . . . . . 321
push.. . . . . . . . . . . . 323
pull.. . . . . . . . . . . . 324
commit.. . . . . . . . . . . . 324
add.. . . . . . . . . . . . 325
branch/checkout.. . . . . . . . . . 325
tag.. . . . . . . . . . . . 329
gitignore.. . . . . . . . . . . 330
CHAPTER 16: Common Infrastructure as Code Technologies.. . . . . 333
File Formats. . . . . . . . . . . 334
Utilities.. . . . . . . . . . . . 335
Continuous Integration/Continuous Deployment (CI/CD).. . . 338
Advanced Git Topics.. . . . . . . . . 339
CHAPTER 17: Container, Cloud, and Orchestration Concepts.. . . . . 343
Kubernetes Benefits and Application Use Cases.. . . . . 344
Single-Node, Multicontainer Use Cases. . . . . . 346
Container Persistent Storage.. . . . . . . . 346
Container Networks.. . . . . . . . . 347
Service Mesh.. . . . . . . . . . . 349
Bootstrapping. . . . . . . . . . . 350
Container Registries.. . . . . . . . . 350
Part IV: Troubleshooting
CHAPTER 18: Analyze and Troubleshoot Storage Issues.. . . . . . 353
High Latency.. . . . . . . . . . . 353
Input/Output Operations per Second (IOPS) Scenarios.. . . 354
Capacity Issues.. . . . . . . . . . 355
Filesystem Issues. . . . . . . . . . 358
I/O Scheduler. . . . . . . . . . . 359
Device Issues.. . . . . . . . . . . 360
Mount Option Problems.. . . . . . . . . 363
CHAPTER 19: Analyze and Troubleshoot Network Resource Issues.. . . . 365
Network Configuration Issues.. . . . . . . . 365
Firewall Issues.. . . . . . . . . . 367
Interface Errors.. . . . . . . . . . 367
Bandwidth Limitations. . . . . . . . . 373
Name Resolution Issues. . . . . . . . . 374
Testing Remote Systems.. . . . . . . . . 375
CHAPTER 20: Analyze and Troubleshoot Central Processing Unit (CPU) and Memory Issues. . . . 379
Runaway Processes.. . . . . . . . . . 379
Zombie Processes.. . . . . . . . . . 380
High Load Average.. . . . . . . . . . 383
High Run Queues.. . . . . . . . . . 384
CPU Times.. . . . . . . . . . . 384
CPU Process Priorities.. . . . . . . . . 384
Memory Exhaustion.. . . . . . . . . 385
Out of Memory (OOM). . . . . . . . . 385
Swapping.. . . . . . . . . . . 386
Hardware. . . . . . . . . . . 388
CHAPTER 21: Analyze and Troubleshoot User Access and File Permissions. . . 397
User Login Issues.. . . . . . . . . . 397
User File Access Issues. . . . . . . . . 400
Password Issues. . . . . . . . . . 404
Privilege Elevation.. . . . . . . . . . 405
Quota Issues. . . . . . . . . . . 405
CHAPTER 22: Use systemd to Diagnose and Resolve Common Problems with a Linux System. . . . . 411
Unit Files. . . . . . . . . . . 412
Common Problems.. . . . . . . . . . 429
9780137898558, TOC, 8/11/2022
