Kubernetes Native Java with Spring Boot (DevCon 2022)

The Spring ecosystem provides you with all you need to build cloud-native applications, focusing on productivity, simplicity, and speed. It’s ready to leverage cloud environment features and integrates with Kubernetes natively.

In this session, Thomas will cover common patterns and best practices to build cloud-native applications with Java using the reactive programming paradigm in Spring Framework 6, which provides better performance, resilience, and efficiency. You’ll then see how to containerize them with Cloud Native Buildpacks, configure them through the natively supported ConfigMaps and Secrets, and deploy them to a Kubernetes cluster with Knative.

Finally, he’ll show how to use the new capabilities in Spring Boot 3 to build native executables on GraalVM and achieve applications with almost instant startup time and reduced memory consumption, perfect for serverless architectures.

Transcript

1. Thomas Vitale
   DevCon
   Nov 9th, 2022
   Kubernetes Native Java
   With Spring Boot
   @vitalethomas
   

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2. Systematic
   • Software Architect at
   Systematic, Denmark.
   
   • Author of “Cloud Native Spring
   in Action” (Manning).
   
   • OSS contributor (Java, Spring,
   Cloud Native Technologies)
   Thomas Vitale
   thomasvitale.com @vitalethomas
   

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3. Cloud Native
   @vitalethomas
   

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4. Why Cloud Native?
   Speed
   Faster and
   fl
   exible delivery
   Cost
   
   
   Ef
   fi
   ciency and cost optimisation
   Scale
   Elasticity and dynamic scaling
   Resilience
   Availability and stability
   @vitalethomas
   

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5. From Development to Production
   A Cloud Native Journey
   Spring Boot
   Development
   Cloud Native
   Buildpacks
   Containerization
   Kubernetes
   Deployment
   @vitalethomas
   

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6. Cloud Native Development
   @vitalethomas
   

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7. Cloud Native Development
   Development principles with Spring Boot
   • Self-contained application
   • Embedded server
   
   • No external dependencies
   
   • JAR packaging (“uber-JAR”)
   
   • Externalized con
   fi
   guration
   • Property
   fi
   les for default values
   
   • JVM system variables
   
   • Environment variables
   @vitalethomas
   

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8. Packaging Spring Boot
   Standalone JAR
   JAR
   Gradle
   
   
   bootJar
   Maven
   
   
   spring-boot:repackage
   @vitalethomas
   

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9. Containerization
   @vitalethomas
   

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10. Image
    pack build
    Cloud Native Buildpacks
    From source code to container image
    @vitalethomas
    

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11. Packaging Spring Boot
    JAR & Container Image
    JAR
    Container Image
    Gradle
    
    
    bootJar
    Maven
    
    
    spring-boot:repackage
    Gradle
    
    
    bootBuildImage
    Maven
    
    
    spring-boot:build-image
    @vitalethomas
    

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12. Spring Boot on Kubernetes
    @vitalethomas
    

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13. Knative
    Serverless experience on Kubernetes
    @vitalethomas
    

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14. Serverless Architectures
    Developers focus on code
    Focus on business logic
    Developer
    Platform
    Infrastructure
    
    Provisioning
    Workload
    
    Management
    Dynamic
    
    Scaling
    @vitalethomas
    

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15. Knative Serving
    Serverless Experience on Kubernetes
    Developer-friendly
    
    abstractions
    From image to URL
    Autoscaling
    
    Scaling to zero
    Progressive
    
    Rollouts
    Request-driven
    
    Event-driven
    Cloud agnostic
    @vitalethomas
    

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16. Configuring Resources
    CPU & Memory
    CPU
    Memory
    When limit hit
    
    
    Throttle
    Compressible
    
    
    Resource
    When limit hit
    
    
    OOMKilled
    Non
    
    
    Compressible
    
    
    Resource
    @vitalethomas
    

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17. Liveness and Readiness Probes
    Application
    ALIVE?
    READY?
    NO
    NO
    Restart might help.
    Restart won’t help.
    
    Don’t send any tra
    ffi
    c
    
    until it’s ready.
    @vitalethomas
    

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18. Health Probes
    Liveness and readiness
    • Spring Boot
    • Use Spring Boot Actuator
    
    • Liveness and readiness health
    endpoints are automatically
    exposed when Kubernetes is
    detected.
    
    • Kubernetes
    • Con
    fi
    gure liveness probe
    
    • Con
    fi
    gure readiness probe
    @vitalethomas
    

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19. Liveness and Readiness Probes
    When not available,
    
    Kubernetes will restart
    
    the container
    When not ready,
    
    Kubernetes will not send
    
    any tra
    ff
    i
    c to the container
    @vitalethomas
    

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20. Externalised Configuration
    @vitalethomas
    

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21. Code, Configuration, Credentials
    Code
    Con
    fi
    guration Deploy
    Credentials
    @vitalethomas
    

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22. Configuration Options
    Spring Boot Properties
    ‣Property
    fi
    les
    
    
    ‣Command line arguments
    
    
    ‣Environment variables
    Con
    fi
    guration Services
    ‣Spring Cloud Con
    fi
    g Server
    
    
    ‣Spring Cloud Consul Con
    fi
    g
    
    
    ‣Spring Cloud Vault
    
    
    ‣Spring Cloud Zookeeper Con
    fi
    g
    Cloud Platform Services
    ‣Spring Cloud Alibaba
    
    
    ‣Spring Cloud AWS
    
    
    ‣Spring Cloud Azure
    
    
    ‣Spring Cloud GCP
    Kubernetes Platform
    ‣Con
    fi
    gMaps
    
    
    ‣Secrets
    
    
    ‣Environment variables
    @vitalethomas
    

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23. ConfigMaps & Secrets
    Mount the volume
    
    to the /config path,
    
    where Spring Boot will
    
    automatically read
    
    property
    fi
    les.
    Load the Con
    fi
    gMap
    
    In a volume
    @vitalethomas
    

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24. Graceful shutdown
    Spring Boot and Kubernetes
    • Spring Boot
    • Enable graceful shutdown
    
    • De
    fi
    ne a grace period
    
    • Kubernetes
    • Add pre-stop hook
    
    • De
    fi
    ne a grace period
    @vitalethomas
    

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25. Native Images
    @vitalethomas
    

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26. Spring Boot 3
    Native executables with GraalVM
    Slower
    
    Heavier
    
    Build
    Instant
    
    Startup
    Reduced
    
    Memory
    
    Consumption
    Instant
    
    Peak
    
    Performance
    Fewer
    
    Runtime
    
    Optimizations
    @vitalethomas
    

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27. Resources
    @vitalethomas
    

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28. Resources
    Source code
    • Presentation source code
    
    • Developer experience with Java on Kubernetes
    
    • Docker
    fi
    les vs. Cloud Native Buildpacks
    
    • Knative and Spring: Bringing back the func
    @vitalethomas
    

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29. https://github.com/ThomasVitale/awesome-spring
    

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30. Discount codes
    Manning
    • 35% discount code, valid for
    all products in all format
    
    • ctwdevcon22
    
    
    • manning.com
    @vitalethomas
    

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31. Thomas Vitale
    DevCon
    Nov 9th, 2022
    Kubernetes Native Java
    With Spring Boot
    @vitalethomas
    @thomasvitale@mastodon.online
    

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