Microservices with Spring Boot and Spring Cloud: Build resilient and scalable microservices using Spring Cloud, Istio, and Kubernetes, 2nd Edition

Cover
Copyright
Contributors
Table of Contents
Preface
Part I - Getting Started with Microservice Development Using Spring Boot
Chapter 1: Introduction to Microservices
Technical requirements
My way into microservices
Benefits of autonomous software components
Challenges with autonomous software components
Enter microservices
A sample microservice landscape
Defining a microservice
Challenges with microservices
Design patterns for microservices
Service discovery
Problem
Solution
Solution requirements
Edge server
Problem
Solution
Solution requirements
Reactive microservices
Problem
Solution
Solution requirements
Central configuration
Problem
Solution
Solution requirements
Centralized log analysis
Problem
Solution
Solution requirements
Distributed tracing
Problem
Solution
Solution requirements
Circuit breaker
Problem
Solution
Solution requirements
Control loop
Problem
Solution
Solution requirements
Centralized monitoring and alarms
Problem
Solution
Solution requirements
Software enablers
Other important considerations
Summary
Chapter 2: Introduction to Spring Boot
Technical requirements
Spring Boot
Convention over configuration and fat JAR files
Code examples for setting up a Spring Boot application
The magic @SpringBootApplication annotation
Component scanning
Java-based configuration
Spring WebFlux
Code examples of setting up a REST service
Starter dependencies
Property files
Sample RestController
springdoc-openapi
Spring Data
Entity
Repositories
Spring Cloud Stream
Code examples for sending and receiving messages
Docker
Summary
Questions
Chapter 3: Creating a Set of Cooperating Microservices
Technical requirements
Introducing the microservice landscape
Information handled by the microservices
Product service
Review service
Recommendation service
Product composite service
Infrastructure-related information
Temporarily replacing service discovery
Generating skeleton microservices
Using Spring Initializr to generate skeleton code
Setting up multi-project builds in Gradle
Adding RESTful APIs
Adding an API and a util project
The API project
The util project
Implementing our API
Adding a composite microservice
API classes
Properties
Integration component
Composite API implementation
Adding error handling
The global REST controller exception handler
Error handling in API implementations
Error handling in the API client
Testing APIs manually
Adding automated microservice tests in isolation
Adding semi-automated tests of a microservice landscape
Trying out the test script
Summary
Questions
Chapter 4: Deploying Our Microservices Using Docker
Technical requirements
Introduction to Docker
Running our first Docker commands
Challenges with running Java in Docker
Limiting available CPUs
Limiting available memory
Using Docker with one microservice
Changes in source code
Building a Docker image
Starting up the service
Running the container detached
Managing a landscape of microservices using Docker Compose
Changes in the source code
Starting up the microservice landscape
Automating tests of cooperating microservices
Troubleshooting a test run
Summary
Questions
Chapter 5: Adding an API Description Using OpenAPI
Technical requirements
Introduction to using springdoc-openapi
Adding springdoc-openapi to the source code
Adding dependencies to the Gradle build files
Adding OpenAPI configuration and general API documentation to the ProductCompositeService
Adding API-specific documentation to the ProductCompositeService interface
Building and starting the microservice landscape
Trying out the OpenAPI documentation
Summary
Questions
Chapter 6: Adding Persistence
Technical requirements
Chapter objectives
Adding a persistence layer to the core microservices
Adding dependencies
Storing data with entity classes
Defining repositories in Spring Data
Writing automated tests that focus on persistence
Using Testcontainers
Writing persistence tests
Using the persistence layer in the service layer
Logging the database connection URL
Adding new APIs
Calling the persistence layer from the service layer
Declaring a Java bean mapper
Updating the service tests
Extending the composite service API
Adding new operations in the composite service API
Adding methods in the integration layer
Implementing the new composite API operations
Updating the composite service tests
Adding databases to the Docker Compose landscape
The Docker Compose configuration
Database connection configuration
The MongoDB and MySQL CLI tools
Manual tests of the new APIs and the persistence layer
Updating the automated tests of the microservice landscape
Summary
Questions
Chapter 7: Developing Reactive Microservices
Technical requirements
Choosing between non-blocking synchronous APIs and event-driven asynchronous services
Developing non-blocking synchronous REST APIs
An introduction to Project Reactor
Non-blocking persistence using Spring Data for MongoDB
Changes in the test code
Non-blocking REST APIs in the core services
Changes in the APIs
Changes in the service implementations
Changes in the test code
Dealing with blocking code
Non-blocking REST APIs in the composite services
Changes in the API
Changes in the service implementation
Changes in the integration layer
Changes in the test code
Developing event-driven asynchronous services
Handling challenges with messaging
Consumer groups
Retries and dead-letter queues
Guaranteed order and partitions
Defining topics and events
Changes in the Gradle build files
Consuming events in the core services
Declaring message processors
Changes in the service implementations
Adding configuration for consuming events
Changes in the test code
Publishing events in the composite service
Publishing events in the integration layer
Adding configuration for publishing events
Changes in the test code
Running manual tests of the reactive microservice landscape
Saving events
Adding a health API
Using RabbitMQ without using partitions
Using RabbitMQ with partitions
Using Kafka with two partitions per topic
Running automated tests of the reactive microservice landscape
Summary
Questions
Part II - Leveraging Spring Cloud to Manage Microservices
Chapter 8: Introduction to Spring Cloud
Technical requirements
The evolution of Spring Cloud
Using Netflix Eureka for service discovery
Using Spring Cloud Gateway as an edge server
Using Spring Cloud Config for centralized configuration
Using Resilience4j for improved resilience
Sample usage of the circuit breaker in Resilience4j
Using Spring Cloud Sleuth and Zipkin for distributed tracing
Summary
Questions
Chapter 9: Adding Service Discovery Using Netflix Eureka
Technical requirements
Introducing service discovery
The problem with DNS-based service discovery
Challenges with service discovery
Service discovery with Netflix Eureka in Spring Cloud
Setting up a Netflix Eureka server
Connecting microservices to a Netflix Eureka server
Setting up the configuration for development use
Eureka configuration parameters
Configuring the Eureka server
Configuring clients to the Eureka server
Trying out the discovery service
Scaling up
Scaling down
Disruptive tests with the Eureka server
Stopping the Eureka server
Stopping a review instance
Starting up an extra instance of the product service
Starting up the Eureka server again
Summary
Questions
Chapter 10: Using Spring Cloud Gateway to Hide Microservices behind an Edge Server
Technical requirements
Adding an edge server to our system landscape
Setting up Spring Cloud Gateway
Adding a composite health check
Configuring a Spring Cloud Gateway
Routing rules
Trying out the edge server
Examining what is exposed outside the Docker engine
Trying out the routing rules
Calling the product composite API through the edge server
Calling the Swagger UI through the edge server
Calling Eureka through the edge server
Routing based on the host header
Summary
Questions
Chapter 11: Securing Access to APIs
Technical requirements
Introduction to OAuth 2.0 and OpenID Connect
Introducing OAuth 2.0
Introducing OpenID Connect
Securing the system landscape
Protecting external communication with HTTPS
Replacing a self-signed certificate at runtime
Securing access to the discovery server
Changes in the Eureka server
Changes in Eureka clients
Adding a local authorization server
Protecting APIs using OAuth 2.0 and OpenID Connect
Changes in both the edge server and the product-composite service
Changes in the product-composite service only
Changes to allow Swagger UI to acquire access tokens
Changes in the test script
Testing with the local authorization server
Building and running the automated tests
Testing the protected discovery server
Acquiring access tokens
Acquiring access tokens using the client credentials grant flow
Acquiring access tokens using the authorization code grant flow
Calling protected APIs using access tokens
Testing Swagger UI with OAuth 2.0
Testing with an external OpenID Connect provider
Setting up and configuring an account in Auth0
Applying the required changes to use Auth0 as an OpenID provider
Changing the configuration in the OAuth resource servers
Changing the test script so it acquires access tokens from Auth0
Running the test script with Auth0 as the OpenID Connect provider
Acquiring access tokens using the client credentials grant flow
Acquiring access tokens using the authorization code grant flow
Calling protected APIs using the Auth0 access tokens
Getting extra information about the user
Summary
Questions
Chapter 12: Centralized Configuration
Technical requirements
Introduction to the Spring Cloud Configuration server
Selecting the storage type of the configuration repository
Deciding on the initial client connection
Securing the configuration
Securing the configuration in transit
Securing the configuration at rest
Introducing the config server API
Setting up a config server
Setting up a routing rule in the edge server
Configuring the config server for use with Docker
Configuring clients of a config server
Configuring connection information
Structuring the configuration repository
Trying out the Spring Cloud Configuration server
Building and running automated tests
Getting the configuration using the config server API
Encrypting and decrypting sensitive information
Summary
Questions
Chapter 13: Improving Resilience Using Resilience4j
Technical requirements
Introducing the Resilience4j resilience mechanisms
Introducing the circuit breaker
Introducing the time limiter
Introducing the retry mechanism
Adding the resilience mechanisms to the source code
Adding programmable delays and random errors
Changes in the API definitions
Changes in the product-composite microservice
Changes in the product microservice
Adding a circuit breaker and a time limiter
Adding dependencies to the build file
Adding annotations in the source code
Adding fail-fast fallback logic
Adding configuration
Adding a retry mechanism
Adding the retry annotation
Adding configuration
Adding automated tests
Trying out the circuit breaker and retry mechanism
Building and running the automated tests
Verifying that the circuit is closed under normal operations
Forcing the circuit breaker to open when things go wrong
Closing the circuit breaker again
Trying out retries caused by random errors
Summary
Questions
Chapter 14: Understanding Distributed Tracing
Technical requirements
Introducing distributed tracing with Spring Cloud Sleuth and Zipkin
Adding distributed tracing to the source code
Adding dependencies to build files
Adding configuration for Spring Cloud Sleuth and Zipkin
Adding Zipkin to the Docker Compose files
Trying out distributed tracing
Starting up the system landscape with RabbitMQ as the queue manager
Sending a successful API request
Sending an unsuccessful API request
Sending an API request that triggers asynchronous processing
Monitoring trace information passed to Zipkin in RabbitMQ
Using Kafka as a message broker
Summary
Questions
Part III - Developing Lightweight Microservices Using Kubernetes
Chapter 15: Introduction to Kubernetes
Technical requirements
Introducing Kubernetes concepts
Introducing Kubernetes API objects
Introducing Kubernetes runtime components
Creating a Kubernetes cluster using Minikube
Working with Minikube profiles
Working with the Kubernetes CLI, kubectl
Working with kubectl contexts
Creating a Kubernetes cluster
Trying out a sample deployment
Managing a local Kubernetes cluster
Hibernating and resuming a Kubernetes cluster
Terminating a Kubernetes cluster
Summary
Questions
Chapter 16: Deploying Our Microservices to Kubernetes
Technical requirements
Replacing Netflix Eureka with Kubernetes Services
Introducing how Kubernetes will be used
Using Spring Boot's support for graceful shutdown and probes for liveness and readiness
Introducing Helm
Running Helm commands
Looking into a Helm chart
Helm templates and values
The common library chart
The ConfigMap template
The Secrets template
The Service template
The Deployment template
The components charts
The environment charts
Deploying to Kubernetes for development and test
Building Docker images
Resolving Helm chart dependencies
Deploying to Kubernetes
Changes in the test script for use with Kubernetes
Testing the deployment
Testing Spring Boot's support for graceful shutdown and probes for liveness and readiness
Deploying to Kubernetes for staging and production
Changes in the source code
Deploying to Kubernetes
Cleaning up
Summary
Questions
Chapter 17: Implementing Kubernetes Features to Simplify the System Landscape
Technical requirements
Replacing the Spring Cloud Config Server
Changes required to replace the Spring Cloud Config Server
Replacing the Spring Cloud Gateway
Changes required to replace the Spring Cloud Gateway
Automating certificate provisioning
Testing with Kubernetes ConfigMaps, Secrets, Ingress, and the cert-manager
Rotating certificates
Deploying to Kubernetes for staging and production
Verifying that the microservices work without Kubernetes
Changes in the Docker Compose files
Testing with Docker Compose
Summary
Questions
Chapter 18: Using a Service Mesh to Improve Observability and Management
Technical requirements
Introducing service meshes using Istio
Introducing Istio
Injecting Istio proxies into microservices
Introducing Istio API objects
Simplifying the microservice landscape
Replacing Kubernetes Ingress controller with Istio ingress gateway
Replacing the Zipkin server with Istio's Jaeger component
Deploying Istio in a Kubernetes cluster
Setting up access to Istio services
Creating the service mesh
Source code changes
Content in the _istio_base.yaml template
Content in the _istio_dr_mutual_tls.yaml template
Running commands to create the service mesh
Observing the service mesh
Securing a service mesh
Protecting external endpoints with HTTPS and certificates
Authenticating external requests using OAuth 2.0/OIDC access tokens
Protecting internal communication using mutual authentication (mTLS)
Ensuring that a service mesh is resilient
Testing resilience by injecting faults
Testing resilience by injecting delays
Performing zero-downtime updates
Source code changes
Virtual services and destination rules
Deployments and services
Tying things together in the prod-env Helm chart
Deploying v1 and v2 versions of the microservices with routing to the v1 version
Verifying that all traffic initially goes to the v1 version of the microservices
Running canary tests
Running blue/green deployment
A short introduction to the kubectl patch command
Performing the blue/green deployment
Running tests with Docker Compose
Summary
Questions
Chapter 19: Centralized Logging with the EFK Stack
Technical requirements
Introducing Fluentd
Overview of Fluentd
Configuring Fluentd
Deploying the EFK stack on Kubernetes
Building and deploying our microservices
Deploying Elasticsearch and Kibana
A walkthrough of the manifest files
Running the deploy commands
Deploying Fluentd
A walkthrough of the manifest files
Running the deploy commands
Trying out the EFK stack
Initializing Kibana
Analyzing the log records
Discovering the log records from microservices
Performing root cause analyses
Summary
Questions
Chapter 20: Monitoring Microservices
Technical requirements
Introduction to performance monitoring using Prometheus and Grafana
Changes in source code for collecting application metrics
Building and deploying the microservices
Monitoring microservices using Grafana dashboards
Installing a local mail server for tests
Starting up the load test
Using Kiali's built-in dashboards
Importing existing Grafana dashboards
Developing your own Grafana dashboards
Examining Prometheus metrics
Creating the dashboard
Trying out the new dashboard
Exporting and importing Grafana dashboards
Setting up alarms in Grafana
Setting up a mail-based notification channel
Setting up an alarm on the circuit breaker
Trying out the circuit breaker alarm
Summary
Questions
Chapter 21: Installation Instructions for macOS
Technical requirements
Installing tools
Installing Homebrew
Using Homebrew to install tools
Install tools without Homebrew
Post-installation actions
Verifying the installations
Accessing the source code
Using an IDE
The structure of the code
Chapter 22: Installation Instructions for Microsoft Windows with WSL 2 and Ubuntu
Technical requirements
Installing tools
Installing tools on Windows
Installing WSL 2 – Windows Subsystem for Linux v2
Installing Ubuntu 20.04 on WSL 2
Installing Windows Terminal
Installing Docker Desktop for Windows
Installing Visual Studio Code and its extension for Remote WSL
Installing tools on the Linux server in WSL 2
Installing tools using apt install
Installing the Spring Boot CLI using sdk install
Installing the remaining tools using curl and install
Verifying the installations
Accessing the source code
The structure of the code
Chapter 23: Native Compiled Java Microservices
Technical requirements
When to native compile Java source code
Introducing the GraalVM project
Introducing the Spring Native project
Compiling source code to a native image
Changes in the source code
Updates to the Gradle build files
Providing native hints as annotations
When underlying frameworks and libraries don't support native compilation
Installing the tracing agent
Installing the tracing agent on macOS
Installing the tracing agent on Ubuntu under WSL 2 in Microsoft Windows
Running the tracing agent
Creating the native images
Testing with Docker Compose
Testing with Kubernetes
Summary
Questions
Packt Page
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Index