Cloud Services and Internet of Things

1 Overview

Introduction and course organization

1.1 Objective

Connect Internet of Things (IoT) enabled devices using scalable cloud services in a project setup.

What you will build

Devices that communicate with cloud services

Devices

• Each device consists of a hardware and a software part
• Usually, real hardware executes software that is loaded onto the hardware
• To simplify development, you can use a script

Cloud Services

• We use real cloud services
• Currently, we have education partnerships with: Google Cloud Computing
• Unfortunately GCP discontinued their IoT Core service :(

1.2 Project Ideas

You should come up with your own project idea, but here is some inspiration:

• 🌡️ Temperature/Humidity Monitoring System
• 🏭 Air Pollution Monitoring System
• 🔕 Noise Level Monitoring System
• 🅿️ Park Spot Monitoring System
• 🩺 Health Monitoring System
• 🚦 Traffic Management System
• 🚂 Railroad Control
• 🪩 Festival Crowd Control
• ...

You don't have to solve complex problems and can also create something funny

1.3 Constraints

• Start from scratch, don't use presets or generators
• Keep project dependencies to a minimum
• Keep it small and simple
• Don't forget tooling and versioning

Consider: The idea of your project does not matter so much, we want to learn workflow and technology here

1.4 Prerequisites

• No formal prerequisites
• It's technical, you will have to code
• Proficiency in a language of your choice

You should have heard of

HTTP, TCP/IP, UDP, SSH, WebSockets, JSON, Git, Docker, API, Continuous Everything, Pull/Merge Request

1.5 Links

Hybrid?

The course takes place in presence.

If you want to participate remotely (e.g. due to covid infection, quarantine or other legitimate reasons), write us an email early enough. We'll ensure to bring the Meeting Owl and start the BBB-Stream. It's not a high-quality hybrid setup though, just sound and a shared screen.

1.6 Schedule

Lecture Sessions

• We'll talk through this slides in presentations
  • Cloud Computing and Services
  • Internet of Things
• Hands On / Assignments
• Call for teams and projects

Working Session

• Working sessions start with the team meetings
  • Every team has a fixed 15 minutes slot
  • Prepare the meeting (what have you done, what are you planning, specific questions to problems, ...)
  • You can use the remaining lecture time to work on the applications
• The remaining time after the team meetings:
  • We can discuss general questions together
  • We can help with specific problems of your projects

Team Meetings

• Every team has a fixed 15 minutes slot
• Prepare the meeting (what have you done, what are you planning, specific questions to problems, ...)
• Attendance is required

Presentation Sessions

• Each member has to present equally
• Unexcused absence will make you fail the course
• Duration: 12 min per team
• Midterm presentations
  • Introduce yourself (who are you, what are you studying, what's your background)
  • Each team presents its current state
  • Check the grading slide for general presentation rules
  • Content: project idea, technology-stack, (maybe schedule, architecture, docker & code)
• Final presentations
  • Each team presents its final state
  • Check the grading slide for important things to present
  • Open and present live in browser
  • Explain architecture, devices, data flow, lessons learned

1.7 Project Submission

Grading is based on the Gitlab repo in the csiot group https://gitlab.mi.hdm-stuttgart.de/groups/csiot

Add a README.md in the repo that contains:

• project name
• members (full name, student short, matriculation number)
• project abstract
• technical documentation
  • Check the grading slide

1.8 Grading

The total of 50 Points is split into 4 categories.

Following general best practices is required for each category.

Although the grades are derived from the team, each individual gets a distinct grade that can differ from the other team members.

• Code & Architecture (20 Points)

  • Naming is consistent and fits best practices of language
  • Code comments make sense and help to understand the flow
  • File/Folder/Package structure is clean and makes sense
  • Most work is done using cloud services, e.g. AWS IoT Events, DynamoDB, ...
  • At least 2 sensors are used
  • At least 2 actuators are used
  • Application contains events that depend on data from multiple devices
  • Application is horizontally scalable (minimum configuration to add or remove devices/things)

• Tooling (15 Points)

  • Deployed code, e.g. lambdas, is tested
  • Infrastructure setup is automated, e.g. with terraform
  • Infrastructure can easily be setup by lecturers

• Presentation (10 Points)

  • Each team member has equal presentation time and content
  • Each team member knows about all areas of the project
  • Group highlights lessons learned
  • Presentation is finished in the alloted time
  • Presentation is well prepared and works

• Technical documentation (5 Points)

  • Contains a very short project abstract
  • Contains setup instructions
  • Contains an architecture diagram
  • Contains a data flow diagram

1.9 Ask for help!

In general:

The Center for Learning and Development, Central study guidance, VS aka student government support you:

• Exam nerves, fear of failure, financial problems, stress, depression, ...
• Bullying, racism, sexism, discrimination, ...
• Tipps and feedback regarding scientific writing (e.g. bachelor thesis)
• Career options after the bachelor
• Support for decision-making

Regarding this course:

• Don't be afraid to ask questions about your project (that won't affect your grading negatively)
• Talk to us early if there are any problems within the group (someone never shows up or does not support the group)

1.10 Questions

• Do you know what you will build?
• Do you know how it is graded?
• Do you know what presentation, lecture, working, Q&A sessions etc. are?
• Anything else?

2 Cloud Computing and Services

Introduction

2.1 What is Cloud?

What do you think?

2.2 Definition

Cloud computing is the on-demand availability of computer system resources, without direct active management by the user.

2.3 Timeline

• 1960s-90s: Initial concepts by Compaq, AT&T, IBM, DEC, ...
• 2002: Amazon creates Amazon Webservices (AWS) and the Elastic Compute Cloud (EC2 2006)
• 2008: Google creates App Engine
• 2008: NASA creates OpenNebula (EU funded)
• 2010: Microsoft creates Azure Cloud
• 2010: NASA and Rackspace create OpenStack based on OpenNebula
• 2012: Google creates Compute Engine
• 2015: Cloud Native Computing Foundation CNCF Landscape

2.4 Service Models

What is: Amazon Elastic Compute Cloud (EC2)? Adobe Creative Cloud? DynamoDB? OpenFaaS? Vercel Functions? Google Firebase? iCloud? GitHub? Vercel? Microsoft 365? Zoom? Azure Virtual Machines? Amazon S3? Gmail? Hosted Kubernetes? Knative? AWS Lambda? Shopify? Google Compute Engine (GCP)? Dropbox?

2.5 Cost estimation

• Cloud providers usually offer tools for cost estimation: https://calculator.aws
• What is expensive? What is cost effective?
• What are the expenses to run our OneMillionPixels application using AWS IoT Core (simplified)?

You have to know your application, requirements and use-cases!

3 Cloud Applications

Introduction

3.1 What is a Cloud Application?

What do you think?

3.2 Definition

A software with an architecture that leverages a multitude of cloud services.

3.3 VideoApp

An example app and web platform that allows friends from all over the world to collaboratively create a movie from their holidays

3.4 VideoApp Features

• Users can sign up to the platform using an eMail or a third party provider
• Users can create holiday groups and invite friends
• Friends can upload raw footage into holiday groups and tag it
• Friends can edit the footage into a movie using an online editor

3.5 VideoApp Requirements

3.6 VideoApp Architecture

Feature: Friends can upload raw footage into holiday groups and tag it

4 Cloud Infrastructure

Introduction

4.1 Technical View

4.2 Organizational View

4.3 Challenges

Short-living resources

Deployment, configuration, maintenance and teardown has to be automated

DevOps

Developers need to understand the runtime environment

Operators need to understand some application layers

New components in the application stack

Service discovery, service configuration, authentification/authorization and monitoring

4.4 Advantages

Continuous everything

Integration, deployment, delivery

High availability

Scalability, reliability, geo replication, disaster recovery

5 Cloud Tooling

Introduction

5.1 Infrastructure as Code

A coded representation for infrastructure allocation and configuration

Options for Infrastructure Configuration

• AWS Management Console
• AWS Infrastructure Composer
• AWS CLI
• AWS CDK
• AWS CloudFormation
• Terraform
• Pulumi

Terraform Example

Example: Creating a S3 Bucket on AWS using Terraform

provider "aws" {
    access_key = "xxx"
    secret_key = "xxx"
    region     = "eu-central-1"
}

resource "aws_s3_bucket" "terraform-example" {
    bucket = "aws-s3-terraform-example"
    acl    = "private"
}

Pulumi Example

Example: Creating a S3 Bucket on AWS using Pulumi

import pulumi
from pulumi_google_native.storage import v1 as storage

config = pulumi.Config()
project = config.require('project')
# Create a Google Cloud resource (Storage Bucket)
bucket_name = "pulumi-goog-native-bucket-py-01"
bucket = storage.Bucket('my-bucket', name=bucket_name, bucket=bucket_name, project=project)

# Export the bucket self-link
pulumi.export('bucket', bucket.self_link)

Other Tools

• Packer
• Docker
• Cloud Init
• Ansible
• Chef
• Puppet

5.2 Continuous Everything

5.3 Monitoring and Alerting

Proper Monitoring/Alerting is essential when CD is applied

AWS CloudWatch

Service for time series data, logs and dashboards

Grafana

Prometheus: Time series database, metric exporters, Alertmanager

Grafana: (Real-time) Dashboards for monitoring data, Alerting Engine

5.4 Backup and Restore

Backup

• Automatic backup of stateful components
• Backup location preferably on external system (e.g. AWS S3)

Restore

• Restore process needs to be defined and tested
• Important for disaster recovery, useful for migration tasks

6 Internet of Things

Introduction

6.1 What is the Internet of Things?

What do you think?

6.2 Definition

A system of interrelated computing devices that can transfer data over a network without human interaction

6.3 Architecture

6.4 Hardware

		Type	CPU (Max)	RAM	OS	TCP/IP	GPIO
DHT22		Sensor	-	-	-	❌	❌
Arduino (ATmega328P)		MCU	20 MHz 8-bit RISC	2 KiB SRAM	-	❌	✅
ESP32 (Xtensa LX6)		SoC	2 * 240 MHz 32-bit RISC	520 KiB SRAM	e.g. FreeRTOS	✅	✅
Raspberry Pi 4 (ARM Cortex-A72)		SoC	4 * 1.5 GHz 64-bit ARM	4 GiB DDR4	GNU/Linux	✅	✅
Random Gaming-PC		PC	8 (HT) * 5.0 GHz 64-bit x86	32 GiB DDR4	e.g. GNU/Linux	✅	❌

6.5 Protocols

The following protocols are often used in an Internet of Things stack

6.6 MQTT

Lightweight, publish-subscribe network protocol that transports messages between devices

MQTT (Version 5) is a OASIS standard and ISO recommendation (ISO/IEC 20922)

• A client sends a message to a topic, e.g. /sensors/temperature/garage
• A client can subscribe to multiple topics, e.g. /sensors/temperature/+

Mosquitto is a popular lightweight server (broker)

MQTT Basics

7 Other topics

7.1 Mutual TLS authentication (mTLS)

What is...

• Asymmetric cryptography
• A certificate authority
• A certificate

X.509

• openssl x509 -in cert.pem -noout -text
• Interesting fields
  • Issuer
  • Subject
  • X509v3 Extended Key Usage
• openssl s_client -connect emqx.services.mi.hdm-stuttgart.de:8883

Important: Server and client certificate do NOT have to be signed by the same CA!

7.2 AWS account setup

• Work as a team on one AWS root account
• Grant access to your teammates using one of the following methods:
  • IAM user → preferred for this course
  • AWS Organizations SSO user (IAM Identity Center) → recommended for professional usage
• Follow the principle of least privilege (start with the policies you currently need, you can add more later)

You don't have to use IaC to manage your account and users

Example policy for IAM users:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "iam:GetAccountPasswordPolicy",
        "iam:ListUsers",
        "iam:GetAccountSummary"
      ],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "iam:GetUser",
        "iam:GetLoginProfile",
        "iam:UpdateLoginProfile",
        "iam:ChangePassword"
      ],
      "Resource": "arn:aws:iam::*:user/${aws:username}"
    },
    {
      "Effect": "Allow",
      "Action": [
        "iam:DeleteAccessKey",
        "iam:GetAccessKeyLastUsed",
        "iam:UpdateAccessKey",
        "iam:CreateAccessKey",
        "iam:ListAccessKeys"
      ],
      "Resource": "arn:aws:iam::*:user/${aws:username}"
    }
  ]
}

8 Hands On

Live demos and practical exercises to learn some new technologies

8.1 Assignment 0: GIT repository

Before you start with the assignments, create a personal project in GitLab and invite us. Push your state regularly during the assignments and follow best practices (e.g. *.pem in .gitignore)

You should do all assignments yourself, of course you can help each other.

8.2 Assignment 1: One Million Pixels (MQTT)

OneMillionPixels is a public canvas, where everyone can draw using MQTT messages.

https://pixels.services.mi.hdm-stuttgart.de

Tasks

• Choose a programming language of your choice and get familiar with an MQTT client library (e.g. paho-mqtt for Python)
• Connect to the MQTT broker with your personal TLS keypair.
• Create a client that publishes pixel data to the given topic to draw in real-time on the one million pixels page.

Connection

Broker

• Host: emqx.services.mi.hdm-stuttgart.de
• Port: 8883
• Topic: csiot/pixels
• TLS: mutual

MQTT message schema

{
  "type": "object",
  "properties": {
    "x": {
      "type": "integer"
    },
    "y": {
      "type": "integer"
    },
    "r": {
      "type": "integer"
    },
    "g": {
      "type": "integer"
    },
    "b": {
      "type": "integer"
    }
  }
}

8.3 Assignment 2: AWS IoT Core (Cloud Console)

Get familiar with the AWS IoT Core service

1. Getting started https://docs.aws.amazon.com/iot/latest/developerguide/iot-quick-start.html
2. Understand the different resource types: https://docs.aws.amazon.com/iot/latest/developerguide/iot-gs-first-thing.html
3. Build your own solution:
   • Connect to the broker without the AWS SDK
   • Create a sender script that publishes random data to: /csiot/${device_name}/temperature
   • Create a receiver script that subscribes to: /csiot/*/temperature
   • Ensure that policies allow access
4. You can publish further data e.g. humidity and choose a more generic subscription to read all values (checkout the mqtt subscription syntax)

8.4 Assignment 3: Terraform Basics

TLS based client-authentication with own CA

Build and maintain your own custom Certificate authority for client-authentication using Terraform.

Reguirements:

• Terraform: https://www.terraform.io/downloads

Tasks

• a) Discuss: What is the role of a CA? Why do we need it in the context of IoT device authentication?
• b) Generate/Apply CA/CSR's/Certificates using the provided solution (adjust for your needs): https://gitlab.mi.hdm-stuttgart.de/csiot/supplementary/handson/-/tree/master/solutions/04-terraform-tls-ca
• c) Use openssl to inspect the generated certificates, e.g. openssl x509 -in a-cert.pem -noout -text
  • Who signed this certificate? For what can this certificate be used?
• d) Use GitLab to store Terraform's state to work as a team on the same CA.

Resources

• https://github.com/hashicorp/learn-terraform-init
• https://registry.terraform.io/providers/hashicorp/tls/latest/docs
• https://registry.terraform.io/providers/hashicorp/local/latest
• https://docs.gitlab.com/ee/user/infrastructure/iac/terraform_state.html#access-the-state-from-your-local-machine

8.5 Assignment 4: AWS IoT Core Devices with Terraform

8.6 Assignment 5: Pimoroni Enviro+ (Gateways software)

• Gateway Software for physical device

8.7 Assignment 6: AWS IoT Core Advanced