DevOps Classroom notes 17/Dec/2025

Microservices

• A monolithic application is broken down into multiple individually runnable services. Each service should handle a functionality
• Each microservice change should be deployed seperately
• Containers are best to run individual microservices, Since there are lots of moving parts we need an orchestrator.

optimizations

• Optimizations refer to
  • size: How to make docker images slim
  • resources: min and max resources
  • security: ensure docker image has no serious security issues

Activity 1:

• Take the multi stage docker image which we have used for spring petclinic
• Find out the size

Steps

• Create an ec2/vm
• create a spring petclinic image
• we need to scan this image for security issues

Things to Remember

• SBOM (Software Bill of Materials)
• Distroless images
• Scanners (Trivy)

Distroless spc

• dockerfile

FROM maven:3-eclipse-temurin-21-alpine AS builder
COPY . /spc
WORKDIR /spc
RUN mvn package


FROM cgr.dev/chainguard/jre:latest
LABEL author=shaikkhajaibrahim
LABEL project=learning
LABEL version=3.3.0
USER nonroot
EXPOSE 8080
COPY --from=builder --chown=nonroot:nonroot /spc/target/spring-petclinic-4.0.0-SNAPSHOT.jar /app/spring-petclinic-4.0.0-SNAPSHOT.jar
WORKDIR /app
CMD ["java", "-jar", "spring-petclinic-4.0.0-SNAPSHOT.jar"]

• After that scan and generate sbom and scan sbom.
• Exercise: Do this for dotnet and react application