restart-q4-2023

Week 1

Week 1 - Day 1

• Installation

Week 1 - Day 2

• OSI Layers - fundamentals
• Layer 1 - Physical
• Layer 2 - Data Link
• Hub vs. Router
• IPv4 vs. IPv6
• Local Network vs. Wide Area Network
• Layer 3 - NETWORK
• Binary -> Decimal conversion
• Decimal -> Binary conversion
• Private IPv4 address classes - class A, class B, class C
• Subnet masking - subnet division

Week 1 - Day 3

• Route Tables
• ARP address resolution protocol
• IP Routing on Layer 3
• Layer 3 problems
• Layer 4 - Transport
• TCP vs. UDP
• TCP segments
• TCP 3 ways handshakes
• VSCode navigation & shortcut tutorials
• Markdown

Week 1 - Day 4

• Encryption types & concept: Plaintext, Algorithm, Key (Symmetric, Public, Private), Ciphertext
• Symmetric Encryption
• Assymetric Encrytion
• Signing & Digital Signature
• Hashing
• Hashing vs. Symmetric Encryption
• Hashing Collision
• Weak Hashing vs. Strong Hashing
• Digital Signature of Hash Digest
• Data Keys, Master Key and key rotation
• Envelop Encryption
• End-to-End Encryption
• Git fundamental git init, git add ., git commit -m "message", git log, git checkout [commit hash]
• Gitlense as VSCode extension

Week 1 - Day 5

• git diff [commit hash] to compare the current with past commits
• git tag "vX.Y.Z"
• to change tag git tag [new name] [old name] then git tag -d [old tag]
• to list all tags git tag -l
• git checkout tags/[tag]
• git checkout [branch]
• create branch git branch [branch name]
• git checkout [branch name], but before that you have to commit unstaged/staged changes
• git merge [branch name], usually from main branch to pull changes to main
• git branch -a --merged to see past merged branches
• git branch -d [branch name], to do delete branches, but this is not recommended
• Create Repo on Github > Clone to local > make local commit > push changes with git push

Week 2

Week 2 - Day 1

• Python in REPL mode
• variable & value assignment
• integer int/float type float/string type str/boolean type Boolean
• checking type of variables/values via type(var)
• getting user input via prompt or terminal waiting via input("input message")
• string my_str.upper() and my_str.lower() function - in place
• list and nested list []
• access item/item of lists
• check length of list/string via len(my_list) or len(my_str)
• list in place functions my_list.append(), my_list.insert(), my_list.pop(index=0)
• my_list.sort() (in-place) vs sorted(my_list) (copy)
• casting types int(my_string) or str(my_float)
• type hinting via type assignment
• no true constant problem in Python

Week 2 - Day 2

• tupple type similar to list but it is immutable
• sets type, theory of how git works with my_set.intersection(other_set) & my_set.difference(other_set)
• dictionary dict type, dict() initialization
• open() to open files
• boolean type and logic evaluation
• if elif else flow control
• while/break loop

Week 2 - Day 3

• match/case flow control
• Enum class via import from enum import Enum
• match/case and Enum combination for clean flow control
• for loop with range(x)
• for loop to iterate over a list
• list comprehension, quickly transform individual items of a list and put into a new list
• for loop with access to both index and item of a list with for index,item in enumerate(my_list):
• for loop with access to key and value of a dict with for k,v in my_dict.items():
• simple Queue data structure implementation via list
• functions, pure and impure functions, input/output, side effects
• in scope and out of scope

Week 2 - Day 4

• Exception basics
• assert
• simple unit testing with assert
• try/except flow
• assign Exception into variable for further actions except Exception as e
• multiple try/except flows
• try/except/else flow

Week 2 - Day 5

• class and object concepts
• creating class and object
• class: property, method, __dict__ representation
• simple inheritance
• inheritance with custom property and method override

Week 3

Week 3 - Day 1

• sub-modules
• data transfer object theory (DTO)
• dataclasses
• Pydantic package
• dataclasses vs. Pydantic
• @classmethod

Week 3 - Day 2

• Regex, Regex visualizer, Regex testing
• Integration theory: messaging, file sharing, RPC (includes REST API & gRPC)
• OSI Layers revision
• JSON serialization & JSON parsing
• Postman API Client
• Testing some public API such as http.cat

Week 3 - Day 3

• API theory: Data Transfer Object or DTO
• Building API on top of Pydantic Schema classes
• HTTP Codes
• FastAPI input auto-parser via Pydantic classes
• PUT API building
• GET API building
• Distinguish 4 ways to provide data: Header, Body, Path Parameters, Query Parameters
• API auto-docs

Week 3 - Day 4

• API auto-docs best practices - including always type hint your API returns
• Adding basic persistence for API
• Continuation with API: PUT, GET, DELETE, and GET multiple items

Week 3 - Day 5

• VSCode debugger setup
• Debugging techniques
• Dependency injection theory
• Testing theory: unit testing, integration testing, end-end testing, smoke testing, regression testing...
• Pytest unit testing pytest, pytest -s, pytest --vl
• FastAPI TestClient from fastapi.testclient import TestClient
• unit testing API

Week 4

Week 4 - Day 1

• Pytest Fixture
• Using @pytest.fixture to create new instance of API Client for each test, or set default data
• Parametizing test functions @pytest.mark.parametrize
• Data Access Object theory DAO

Week 4 - Day 2

• Install DB client within VSCode
• Installing SQLite
• Playing with Sakila.db
• SQL SELECT, COUNT, DISTINCT, GROUP BY, WHERE, LIMIT, OFFSET with logic operators
• SQL JOIN
• SQL INSERT INTO ... VALUES
• SQL UPDATE

Week 4 - Day 3

• More SQL UPDATE
• Python virtual environment venv
• SQLModel - as a Relational Object Mapping tool (ORM)
• Revisit DTO, DAO theory
• Building simple SQL model
• Building simple API with automatic DTO <-> DAO conversion

Week 4 - Day 4

• SQL primary key vs index key vs compound index key
• SQL foreign key constraint
• Building APIs with SQLModel ORM
• Learning why we should have dedicated DTO & DAO layers, shouldn't rely on automatic conversion

Week 4 - Day 5

• Mainly to discuss Assignment 1

Week 5

Week 5 - Day 1

• Intro to Cloud Computing
• IaaS vs. PaaS vs. SaaS
• Platform engineering responsibility

Week 5 - Day 2

• Advantages of Cloud Computing
• What is AWS?
• AWS Pricing Model and unit cost charges
• FinOps
• Total Cost of Ownership comparison
• AWS API vs. Management Console vs. CLI vs. SDK

Week 5 - Day 3

• AZ, and why use 3 AZs
• Region
• Local services vs. Global services (domain name services DNS, IAM, CDN)
• POP = Edge Locations + Edge Caches
• CDN
• Storage Services overview
• Networking Services overview
• Security Services overview
• Management Services overview - Landing Zone and why split AWS accounts
• Integration Services overview

Week 5 - Day 4

• Shared responsibility model examples (Self managed DB vs. RDS)
• S3 Service concepts
• S3 Tiers
• S3 DNS overview
• S3 Cost charges model
• EC2 recommended usecases
• Create EC2 instance
  • AMI & Golden Image practice
  • Instance Type, Instance family & size
  • Network settings, high availability setups
  • IAM Role, Instance profile
  • User data script
  • Instance Store vs. EBS drives
  • Tag & ABAC
  • TBC...

Week 5 - Day 5

• EC2 labs
• Linux commands labs
• Stateful vs. Stateless firewalls
• Security Groups
• Practical ways to use Security Groups
• How multiple component groups work together via ALB, dedicated Security Group for different application component groups

Week 6

Week 6 - Day 1

• How DNS works, TLD, Name Server, Zone, Zone File
• Traversing DNS Tree
• DNS Records: NS, A, AAAA, Alias (unique to AWS), CNAME, TXT
• Drawio, multiple drawing exercises

Week 6 - Day 2

• Public & Private IP
• IGW
• Security Group
• NACL
• ALB
• NATGW
• Subnets division & intro to VPC design

Week 6 - Day 3

• More networking protocols and standard TCP ports
• Comprehensive VPC design
  • How many application tiers (ALB/NATGW, web, app, db...)
  • How many AZs
  • Design the subnets
  • Design public facing tiers ALB/NATGW/Internet GW
  • Design route tables
  • Design the security group

Week 6 - Day 4

• Security Fundamentals
• Prevention methods: Networking
  • NACL
  • SG
  • WAF
  • IPS
  • Subnetting, zoning
  • AWS Network Firewall's implementation
• Prevention methods: PKI
  • DNS
  • CA
  • DNSSEC (more later)
  • Use of CA's certificates
  • Application of ACM

Week 6 - Day 5

• Prevention methods: Data Security
  • Data at rest vs. Data in transit
  • Symmetric vs. Asymmetric vs. Hybrid encryption revision
  • KMS (API only + multi-tenancy) vs. CloudHSM (normally only PKCS 11 or other low level interfaces)
  • Hashing
  • Key algorithm available
  • Never use same key pairs for both encryption & signing
  • Import key materials to KMS
  • Provide CloudHSM with API interface of KMS
  • CloudHSM deployment model
• Prevention methods: IAM
  • IAM Policy
  • IAM Role
  • IAM User
  • IAM Group
  • Condition & permission boundary example

Week 7

Week 7 - Day 1

• RDS vs. DynamoDB
  • Deployment model
  • Access via VPC
  • Performance
  • Scaling characteristic
  • Pricing structure
  • Consistency profile
• DynamoDB
  • Partitioning
  • Primary key vs. Compound Key (Partition Key, Sort Key)
  • WCR, RCU
  • On-demand vs. Provisioned Throughput
  • Query
  • Scan
  • GSI - global secondary index
  • Global table
  • DynamoDB Stream, capturing change data capture, upsert table, enabling analytics

Week 7 - Day 2

• DevOps team job functions
  • DevOps Engineer
  • Cloud Engineer
  • Site Reliability Engineer
  • Platform Engineer
  • Pipeline Engineer
  • Integration Engineer
• System Manager overview
• Parameter Store, KMS deep discussion
• IaC imperative vs. declarative
• Cloud Formation

Week 7 - Day 3

• Elastic Load Balancing
• Types of load balancers:
  • Application
  • Gateway
  • Network
  • Classic
• Bastion host
• Autoscaling applications:
  • ALB
  • Target group
  • Register EC2 instance into Target groups
  • Create Listener to ALB
• Types of scaling rules:
  • Manual
  • Scheduled
  • Dynamic - via metric and alarms
  • Predictive
• Auto scaling best practices

Week 7 - Day 4

• Route 53 services, highlighted routing
  • Simple
  • Failover
  • IP based
  • Geolocation based
• CloudFront
  • Concepts of how CDN delivery & secure contents
  • TTL and invalidations
  • SSL/SNI
  • OAI
  • Custom Geolocation distribution
  • Private content hosting
• Lambda service & usecases

Week 8

Week 8 - Day 1

• System design primer:
  • Scalability
  • Scalability components
  • Scalability & Performance tradeoff
  • Latency vs. Throughput
  • CAP theory
  • Eventual vs. Strong consistency
  • Active-Passive failover, Active-Active failover
  • Availability
  • CDN
  • Stateful vs. Stateless applications
  • Load Balancing
  • Microservices
  • Normalization vs. Denormalization

Week 8 - Day 2

• Serverless framework intro
• AWS CLI setup
• S3 handson
• Lambda handson
• S3 Events to trigger Lambda

Week 8 - Day 3

• IAM Policy design
• S3 Events to trigger Lambda to resize images

Week 8 - Day 4

• Assignment 2 handsout