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Introduction xxviii
Part I Software Development and Design
Chapter 1 Software Development Essentials 2 "Do I Know This Already?" Quiz 2 A Brief History of the Future 4 The Evolution 5 Automation, Orchestration, and DevOps 6 Software Architecture and Design 9 Architecture Requirements 10 Functional Requirements 13 Nonfunctional Requirements 13 Architectural Patterns 14 Software Development Lifecycle (SDLC) Approach 15 Software Development Models 17 Waterfall 17 Agile Software Development 18 Scrum 19 Extreme Programming 19 Kanban 19 Lean 19 Which Model? 20 Architecture and Code Reviews 21 Software Testing 22 Exam Preparation Tasks 23
Chapter 2 Software Quality Attributes 26 "Do I Know This Already?" Quiz 26 Foundation Topics 29 Quality Attributes and Nonfunctional Requirements 29 Brief Overview of the Most Common Quality Attributes 29 Measuring Quality Attributes 35 Modularity in Application Design 36 Benefits of Modularity 36 Modularity Coding Best Practices 37 Microservices and Modular Design 40 Scalability in Application Design 41 Horizontal Scalability 41 Vertical Scalability 42 Practical Scalability in Application Design 43 High Availability and Resiliency in Application Design 44 Failure or Fault Detection 46 Recovery: High Availability in Practice 47 Prevention 50 High Availability Planning and the Responsibilities of the Developer 50 High Availability Deployment Models 51 Exam Preparation Tasks 53
Chapter 3 Architectural Considerations and Performance Management 56 "Do I Know This Already?" Quiz 57 Foundation Topics 59 Maintainable Design and Implementation 59 Maintaining a SOLID Design 60 Single Responsibility Principle (SRP) 61 Open-Closed Principle (OCP) 62 Liskov''s Substitution Principle (LSP) 63 Interface Segregation Principle (ISP) 64 Dependency Inversion Principle (DIP) 65 Latency and Rate Limiting in Application Design and Performance 66 Designing for Application Low Latency and High Performance 69 Architecture Trade-offs 69 Improving Performance 69 Design and Implementation for Observability 73 Logging 74 Metrics 76 Tracing 77 Good Documentation Practices: An Observability Reminder 78 Database Selection Criteria 79 Database Requirements Gathering 80 Data Volume 81 Data Velocity 82 Data Variety 82 Exam Preparation Tasks 83
Chapter 4 Version Control and Release Management with Git 86 "Do I Know This Already?" Quiz 86 Foundation Topics 88 Version Control and Git 88 Git Workflow 88 Branch and Pull Workflow 89 Pros 89 Cons 89 Sample Setup 90 Sample Branch and Pull Workflow 90 Fork and Pull Workflow 104 Pros 105 Cons 105 Sample Setup 105 Sample Fork and Pull Workflow 106 Git Branching Strategy 121 What Is a Branching Strategy? 121 The Most Important Factor When Selecting a Git Branching Strategy 122 Popular Git Branching Strategies 122 When to Use GitHub Flow 122 When to Use Git Flow 123 When to Use GitLab Flow 123 Recommended GitHub Settings 125 Configuring the PR Merge Button 125 Configuring a Branch Protection Rule to Require Code Reviews 125 Exam Preparation Tasks 127
Part II APIs
Chapter 5 Network APIs 130 "Do I Know This Already?" Quiz 130 Foundation Topics 132 What Are APIs? 132 Methods 133 Objects 134 Formats 134 APIs vs. No API 135 Web Scraping 135 Jeff Bezos''s API Mandate: How the AWS API-Driven Cloud Was Born 136 Calling an API 138 What Is API Development? 144 API Architectural Styles 146 Selecting an API Style 147 HTTP/JSON 149 REST/JSON 150 Cache-Control 151 REST vs. RPC 152 gRPC 154 OpenAPI/Swagger 155 Network API Styles 157 NETCONF APIs 158 Exam Preparation Tasks 160
Chapter 6 API Development 162 "Do I Know This Already?" Quiz 163 Foundation Topics 165 Creating API Clients 165 Code Generation Client API Libraries for IMDb 165 Adding CLI Wrapper Code 174 Making Calls to IMDb Using a CLI Program 174 API Design Considerations 177 API Authentication Models 179 Flow Control (Pagination vs. Streaming) 181 Error Handling, Timeouts, and Rate Limiting 184 Caching 188 Exam Preparation Tasks 189
Part III Application Development, Deployment, and Security
Chapter 7 Application Deployment 192 "Do I Know This Already?" Quiz 193 Foundation Topics 194 The Evolution of Application Responsibilities 194 The Hybridization of Development and Operations 194 The Journey to DevOps 195 A Cultural Shift 196 The Emergence of the Site Reliability Engineer(ing) 196 SRE Responsibilities and Tenets 197 SRE vs. DevOps 198 Continuous Integration/Continuous Delivery (Deployment) 198 Continuous Integration (CI) 199 Continuous Delivery: One of the CDs 200 Continuous Deployment: The Other CD 200 CI/CD Pipeline Implementation 201 Pipeline Components 203 Build 204 Test 205 Release/Deliver 205 Deploy 205 Adding Deployment to Integration 207 Deploying to Infrastructure (Terraform + Atlantis) 207 Deploying Applications (Flux + Kubernetes) 213 Application Deployment Methods over Time 218 The 2000s: Sysadmins, Terminals, and SSH 218 The 2010s: Automated Configuration Management 220 The 2020s: The Clouds Never Looked So Bright 224 Managed Kubernetes (e.g., GKE) 224 Containers on Serverless Clouds (e.g., AWS ECS on Fargate) 227 Serverless Functions (e.g., AWS Lambda) 234 Software Practices for Operability: The 12-Factor App 238 Factor
1: Codebase 239 Factor
2: Dependencies 239 Factor
3: Config 239 Factor
4: Backing Services 240 Factor
5: Build, Release, Run 240 Factor
6: Processes 240 Factor
7: Port Binding 241 Factor
8: Concurrency 241 Factor
9: Disposability 241 Factor
10: Dev/Prod Parity 241 Factor
11: Logs 242 Factor
12: Admin Processes 242 Summary 243 Exam Preparation Tasks 243
Chapter 8 Security in Application Design 246 "Do I Know This Already?" Quiz 247 Foundation Topics 248 Protecting Privacy 250 Personally Identifiable Information 250 Data States 250 Laws, Regulations, and Standards for Protecting Privacy 251 Storing IT Secrets 252 Public Key Infrastructure (PKI) 254 Certificate Revocation 256 Hierarchical Multiple CA Infrastructure 257 TLS, PKI, and Web Applications Security 257 Browser Security Issues 261 Securing Web and Mobile Applications 262 Injection Attacks 263 Cross-Site Scripting 264 OAuth Authorization Framework 266 How Does OAuth Work? 266 OAuth
2.0 Two-Legged Authorization 268 OAuth
2.0 Three-Legged Authorization 269 Additional OAuth Authorization Code Grant Types 271 OAuth
2.0 Client Credentials 271 Resource Owner Password Credential Flow 272 OAuth
2.0 Implicit Flow 275 OAuth
2.0 Authorization Code Flow 276 OAuth
2.0 PKCE Flow 278 Refresh Token Flow 280 OAuth
2.0 Device Code Flow 281 Exam Preparation Tasks 283
Part IV Infrastructure and Automation
Chapter 9 Infrastructure 286 "Do I Know This Already?" Quiz 286 Foundation Topics 288 Network Management 288 Methods of Network Provisioning 290 CLI/Console 291 SNMP 294 File Transfer Methods 297 Element Management Systems 297 Embedded Management 299 Zero-Touch Provisioning (ZTP) 300 Atomic or SDN-Like/Controller-Based Networking 303 Advanced Concepts - Intent-Based Networking 305 Summary 307 Exam Preparation Tasks 307
Chapter 10 Automation 310 "Do I Know This Already?" Quiz 311 Foundation Topics 313 Challenges Being Addressed 313 Differences of Equipment and Functionality 314 Proximity of Management Tools and Support Staff 316 Speed of Service Provisioning 317 Accuracy of Service Provisioning 319 Scale 323 Doing More with Less 329 Software-Defined Networking (SDN) 329 What Is SDN and Network Programmability? 329 Approach 330 Nontraditional Entities 331 Industry Impact 331 New Methods 331 Normalization 332 Enabling Operations 332 Enabling Career Options 332 Use Cases and Problems Solved with SDN 332 Overview of Network Controllers 334 The Cisco Solutions 335 Application Programming Interfaces (APIs) 335 REST APIs 336 API Methods 337 API Authentication 337 API Pagination 337 Payload Data Formats JSON XML 338 XML 338 JSON 340 Cross-Domain, Technology-Agnostic Orchestration (CDTAO) 342 Impact to IT Service Management and Security 343 Exam Preparation Tasks 344
Chapter 11 NETCONF and RESTCONF 346 "Do I Know This Already?" Quiz 346 Foundation Topics 348 Catalyst for NETCONF 348 Content 349 Operations 350 Messages 350 Transport 351 Atomic and Model-Driven Configuration Management 351 How to Implement NETCONF 354 Enabling NETCONF on IOS XE 355 Enabling NETCONF on IOS XR 356 Enabling NETCONF on NX-OS 357 Basic Manual Use of NETCONF 358 YANG Models 365 The Evolution w