Devops Tools and AWS for Java Microservice Developers

Microservices are small, autonomous, and focused services that map to business boundaries; they deploy independently and communicate via APIs over network calls, enabling changes without impacting other services.

Learn how continuous integration, delivery, and deployment streamline code from commit to production, building artifacts, running tests, and using stage and production environments with automated and manual checks.

Discover how aws regions and zones organize the global infrastructure, how edge locations cache requests to reduce latency, and how to view regions, zones, and local zones.

Harness SSH for secure AWS EC2 access over port 22 using a public key on the instance. Download the private key, store it safely, and connect via .ssh/id_rsa.

Connect to your AWS instance from macOS using the SSH command, set pem file permissions, then become root with sudo -i to install tools.

Install PuTTY and PuTTYgen on Windows to enable SSH access to remote machines. Download the official installer, install it, and use PuTTYgen to convert keys.

Learn the linux file system hierarchy by exploring the root directory and key folders like /bin, /boot, /dev, /home, /lib, /mnt, /opt, /proc, /root, /sbin, /tmp, /usr, and /var.

Install git on Windows, including downloading the installer, selecting default components, configuring the path, choosing the preferred terminal, setting line endings, and verifying installation with git --version.

Learn git in action by creating a local repository, adding a file, staging changes, and committing to the master branch, with basic status and branch commands.

Learn to undo changes in git by restoring files to the head version with git checkout, check status with git status, and unstage or reset changes using git reset.

Learn to merge changes from the dev branch into the master branch using git merge, including fast-forward behavior and verification.

Learn to resolve merge conflicts by examining conflicting lines, choosing the correct changes across dev, bug fix, and master branches, then stage and commit the resolved code.

Master git push and pull workflows between local and remote repositories, commit changes with messages, and pull before pushing to resolve conflicts.

Save your current work with git stash, which moves changes to a temporary location so you can switch branches, then restore them later with git stash pop.

Learn to install and use git on a Linux box, connect to an AWS EC2 instance, clone and pull a repo, edit files, push changes, and clean up.

Maven acts as a build automation and project management tool, enforcing convention over configuration. It packages as jar or war, deploys to servers, and uses archetypes with IDE support.

Install and configure Apache Maven on Windows by downloading the Maven zip, extracting it, copying the bin folder, and adding its path to the system path, then verify with mvn -version.

Inspect the Maven installation directory, including the Apache license file and readme, the bin scripts, and the conf and lib folders with settings.xml and core classes.

Navigate to the project directory, run mvn install to compile, test, and package, locate the jar in target, and run it with java -cp to print hello world.

Discover how maven plugins group goals such as compile, test, and package. Explore archetype generate and install, defaults, and overriding compiler versions in pom.xml to build jars or wars.

Explore how Maven coordinates—groupId, artifactId, packaging, and version—determine a project's repository location and final artifact, such as jar, war, or ear. Learn naming conventions and how coordinates enable dependencies.

Create a maven java project, initialize git, and push to GitHub, preparing for Jenkins automation to pull and build the project.

Install maven on the Linux aws instance, connect via ssh, verify java, and create maven projects using archetypes, then build with mvn clean install for dependency resolution.

Install spring tool suite by launching a browser, downloading the latest STS release for your OS (Linux, Mac, or Windows), and completing a straightforward installation.

Configure STS to use the correct JDK by editing preferences, replacing any JRE entry, and pointing the standard VM to the JDK home folder to ensure Maven and Java compile.

Install the MySQL community server on Windows by installing Visual C++, then run the MySQL installer, select server only, and set a root password for use with MySQL Workbench.

Install and configure MySQL Workbench on Windows to connect to MySQL server, create databases, and run queries in the query window.

Install and configure MySQL and MySQL Workbench with a simple three-step setup, create a root password, and ensure MySQL starts on Windows or Mac at port 3306.

Download the zip from the resources section, unzip it, and access three microservice projects—product service, coupon service, and flight services—for hands-on practice with dockerization and docker compose, and Kubernetes manifests.

Create a coupon rest controller using a repository and expose a restful api with endpoints: post to /coupons to create a coupon and get by code to retrieve a coupon.

Configure the data source by editing the application.properties files for the product and coupon services, ensuring both share the same database.

Start the product service on port 1990 to avoid conflicts with the coupon service on 8080, test the product api by posting a json with name, description, and price.

Explore AWS S3, an object-based storage service, to create buckets, upload and download files, manage permissions, and host publicly accessible content via object URLs.

Launch and configure an EC2 instance, install MariaDB and secure it, create the database and tables for the Spring Boot app, then install OpenJDK 21 to prepare for deployment.

Learn how to package a Spring Boot app as a jar file, upload to S3, and retrieve it on EC2 using a pre-assigned URL instead of public access, via wget.

Deploy the coupon service on an EC2 instance by uploading the fat jar to S3, running it with java -jar, and testing the API via Postman.

Deploy a microservice across multiple instances and balance traffic with aws elastic load balancer. Choose among application, classic, or network load balancers for http/https or tcp/udp traffic in a vpc.

Test the elastic load balancer by using its DNS name on port 80 to access the coupon service and verify round-robin routing across two instances.

Troubleshoot load balancer DNS timeouts by opening inbound port 80 in the security group and editing rules to allow http on 80 from anywhere, then save to enable access.

Create an auto scaling group from a launch configuration, select subnets and an optional load balancer, and set CPU-based target tracking to scale between one and four instances.