Docker Containerization

Docker containerization is a technology that packages an application and all its dependencies—such as libraries, system tools, and runtime—into a standardized, isolated unit called a container. This self-contained package ensures that the application runs consistently and reliably across different computing environments, from a developer's laptop to production servers, effectively solving the "it works on my machine" problem. Unlike traditional virtual machines that virtualize an entire operating system, containers share the host system's kernel, making them significantly more lightweight, faster to start, and resource-efficient, which simplifies the process of building, shipping, and deploying software.

  1. Introduction to Virtualization and Containerization
    1. The "Works on My Machine" Problem
      1. Environment Inconsistency Causes
        1. Operating system differences
          1. Library version conflicts
            1. Configuration variations
              1. Dependency management issues
              2. Impact on Development Workflows
                1. Development delays
                  1. Testing complications
                    1. Deployment failures
                      1. Team collaboration challenges
                    2. Virtualization Fundamentals
                      1. Definition and Core Principles
                        1. Hardware Abstraction Layer
                          1. Resource Allocation Concepts
                            1. Hypervisor Technology
                              1. Type 1 Hypervisors
                                1. Bare-metal architecture
                                  1. Examples and use cases
                                    1. Performance characteristics
                                    2. Type 2 Hypervisors
                                      1. Hosted architecture
                                        1. Examples and use cases
                                          1. Performance trade-offs
                                        2. Virtual Machine Architecture
                                          1. Guest operating systems
                                            1. Virtual hardware components
                                              1. Resource isolation mechanisms
                                                1. VM lifecycle management
                                                2. Virtual Machine Benefits
                                                  1. Complete isolation
                                                    1. Multiple OS support
                                                      1. Hardware independence
                                                        1. Snapshot capabilities
                                                        2. Virtual Machine Limitations
                                                          1. Resource overhead
                                                            1. Slow startup times
                                                              1. Storage requirements
                                                                1. Performance penalties
                                                              2. Containerization Fundamentals
                                                                1. Definition and Core Principles
                                                                  1. Operating System Level Virtualization
                                                                    1. Shared Kernel Architecture
                                                                      1. Linux Kernel Features
                                                                        1. Namespaces
                                                                          1. Process ID namespace
                                                                            1. Network namespace
                                                                              1. Mount namespace
                                                                                1. User namespace
                                                                                  1. IPC namespace
                                                                                    1. UTS namespace
                                                                                    2. Control Groups
                                                                                      1. Resource limiting
                                                                                        1. Resource monitoring
                                                                                          1. Process grouping
                                                                                            1. Hierarchical organization
                                                                                          2. Process Isolation Mechanisms
                                                                                            1. Filesystem isolation
                                                                                              1. Network isolation
                                                                                                1. Process tree isolation
                                                                                                  1. User space isolation
                                                                                                  2. Container Benefits
                                                                                                    1. Lightweight resource usage
                                                                                                      1. Fast startup times
                                                                                                        1. Consistent environments
                                                                                                          1. Easy portability
                                                                                                            1. Efficient scaling
                                                                                                            2. Container Limitations
                                                                                                              1. Shared kernel dependency
                                                                                                                1. Security considerations
                                                                                                                  1. OS compatibility constraints
                                                                                                                    1. Limited isolation compared to VMs
                                                                                                                  2. Containers vs Virtual Machines Comparison
                                                                                                                    1. Resource Efficiency Analysis
                                                                                                                      1. Memory footprint comparison
                                                                                                                        1. CPU overhead differences
                                                                                                                          1. Storage requirements
                                                                                                                            1. Network performance
                                                                                                                            2. Portability Characteristics
                                                                                                                              1. Cross-platform compatibility
                                                                                                                                1. Environment consistency
                                                                                                                                  1. Deployment flexibility
                                                                                                                                    1. Migration capabilities
                                                                                                                                    2. Performance Metrics
                                                                                                                                      1. Startup time comparison
                                                                                                                                        1. Runtime performance
                                                                                                                                          1. Scalability characteristics
                                                                                                                                            1. Throughput analysis
                                                                                                                                            2. Security and Isolation
                                                                                                                                              1. Security boundary differences
                                                                                                                                                1. Attack surface analysis
                                                                                                                                                  1. Isolation strength comparison
                                                                                                                                                    1. Use case recommendations