#quarkus tutorial

[codecraftshop]

Watch "Introduction to quarkus - quarkus tutorial | quarkus for beginners | CodeCraftShop" on YouTube

Watch “Introduction to quarkus – quarkus tutorial | quarkus for beginners | CodeCraftShop” on YouTube

[reportwire]

Processing Images in Java With OpenCV and Quarkus

Processing Images in Java With OpenCV and Quarkus

If you are into computer vision, you probably are familiar with OpenCV. It’s an amazing library that has almost everything one needs to do 2D and 3D processing and much more. Gesture recognition, face detection, Motion tracking, think of anything related to image processing and OpenCV can be your goto. It’s based on the BSD license, so you can just download it and start using it. OpenCV is…

[holytheoristtastemaker]

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwN0jcB

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwN0jcB

— Damian Fallon (@DamianFallon2) March 13, 2020

from Twitter https://twitter.com/DamianFallon2

[computingpostcom]

Welcome to this exhilarating tutorial on how to deploy and use Quarkus in Kubernetes. Kubernetes is one of the open-source tools currently preferred when automating system deployments. It makes it easy to scale and manage containerized applications. Kubernetes works by distributing workloads across the cluster and automating the container networking needs. Also, storage and persistent volumes are allocated, by doing so the desired state of container applications is continuously maintained. Quarkus offers provides an easy way to automatically generate the Kubernetes resources based on some defaults and the user-provided configuration. This Kubernetes-native Java framework also provides an extension used to build and push container images to a registry before the application is deployed to the target. Another feature about Quarkus is that it enabled one to use the Kubernetes ConfigMap as a configuration source without mounting them on the pod. The cool features associated with Quarkus are: Community and Standards: It provides a cohesive and fun-to-use full-stack framework by leveraging a growing list of over fifty best-of-breed libraries that you love and use Container First: It offers amazingly fast boot time, incredibly low RSS memory (not just heap size!) offering near-instant scale-up and high density memory utilization in container orchestration platforms like Kubernetes Unifies imperative and reactive: It allows developers to combine both the familiar imperative code and the reactive style when developing applications. Kube-Native: The combination of Quarkus and Kubernetes provides an ideal environment for creating scalable, fast, and lightweight applications. It highly increases the developer productivity with tooling, pre-built integrations, application services e.t.c By following this guide to the end, you will learn how to: Use Quarkus Dekorate extension to automatically generate Kubernetes manifests based on the source code and configuration Build and push images to Docker registry with Jib extension Deploy an application on Kubernetes without any manually created YAML in one click Use Quarkus Kubernetes Config to inject configuration properties from ConfigMap Let’s dive in! Setup Pre-requisites For this guide, you will require: Quarkus CLI Apache Maven 3.8.1+ (Optional) Access to a Kubernetes cluster A Kubernetes cluster can be deployed with the aid of the guides below: Run Kubernetes on Debian with Minikube Deploy Kubernetes Cluster on Linux With k0s Install Kubernetes Cluster on Ubuntu using K3s Install Kubernetes Cluster on Rocky Linux 8 with Kubeadm & CRI-O Once the cluster is running, install kubectl curl -LO "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl" chmod +x kubectl sudo mv kubectl /usr/local/bin Ensure that you can access the cluster. # For k0s export KUBECONFIG=/var/lib/k0s/pki/admin.conf 1. Install Quarkus CLI The Quarkus CLI can be installed on Linux, macOS, and Windows (using WSL or bash compatible shell-like Cygwin or MinGW) by running the below commands: curl -Ls https://sh.jbang.dev | bash -s - trust add https://repo1.maven.org/maven2/io/quarkus/quarkus-cli/ curl -Ls https://sh.jbang.dev | bash -s - app install --fresh --force quarkus@quarkusio You can install it on Windows systems using the Powershell: iex "& $(iwr https://ps.jbang.dev) trust add https://repo1.maven.org/maven2/io/quarkus/quarkus-cli/" iex "& $(iwr https://ps.jbang.dev) app install --fresh --force quarkus@quarkusio" Once installed, restart your shell. The Quarkus CLI can also be installed using SDKMAN as below: sdk install quarkus 2. Create a Project Use the Quarkus command-line interface (CLI) to create a new project. The below command adds resteasy-reactive, Jib, and kubernetes dependencies. quarkus create app quarkus-example --extension=resteasy-reactive,kubernetes,jib

cd quarkus-example Sample Output: After this, you will have several files generated, among these files is the pom.xml file bearing dependencies to the build file: ......... io.quarkus quarkus-resteasy-reactive io.quarkus quarkus-kubernetes io.quarkus quarkus-container-image-jib ...... The good thing with Quarkus is that it generates Deployment/StatefulSet resources that it use your registry_username/test-quarkus-app:tag as the container image of the Pod. The image here is controlled by the Jib extension and can be customized using the application.properties as shown: Open the file for editing: vim src/main/resources/application.properties Add the following lines replacing where required. quarkus.container-image.group=registry_username quarkus.container-image.name=tutorial-app quarkus.container-image.tag=latest quarkus.container-image.username=registry_username quarkus.container-image.password=Your_registry -Password If no registry has not been specified, the default, docker.io registry will be used. A detailed demonstration on specifying a registry has been captured elsewhere in this guide. 3. Build and Deploy your Application Jib is used to build optimized images for Java applications without a Docker daemon and no need for the mastery of deep docker practices. Dekorate is a Java library that makes it simple to generate and decorate Kubernetes manifests. It generates manifests based on the annotations, source code, and configuration variables. Now build and deploy your application using Quarkus CLI: quarkus build -Dquarkus.container-image.push=true Sample Output: After the build process, you will have two files named kubernetes.json and kubernetes.yml under the target/kubernetes/ directory. # ls target/kubernetes kubernetes.json kubernetes.yml Both files contain both the Kubernetes Deployment and Service. For example, the kubernetes.yml file looks like this: # cat target/kubernetes/kubernetes.yml --- apiVersion: v1 kind: Service metadata: annotations: app.quarkus.io/build-timestamp: 2022-07-09 - 10:55:08 +0000 labels: app.kubernetes.io/name: tutorial-app app.kubernetes.io/version: latest name: tutorial-app spec: ports: - name: http port: 80 targetPort: 8080 selector: app.kubernetes.io/name: tutorial-app app.kubernetes.io/version: latest type: LoadBalancer --- apiVersion: apps/v1 kind: Deployment metadata: annotations: app.quarkus.io/build-timestamp: 2022-07-09 - 10:55:08 +0000 labels: app.kubernetes.io/version: latest app.kubernetes.io/name: tutorial-app name: tutorial-app spec: replicas: 1 selector: matchLabels: app.kubernetes.io/version: latest app.kubernetes.io/name: tutorial-app template: metadata: annotations: app.quarkus.io/build-timestamp: 2022-07-09 - 10:55:08 +0000 labels: app.kubernetes.io/version: latest app.kubernetes.io/name: tutorial-app spec: containers: - env: - name: KUBERNETES_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace image: registry_username/tutorial-app:latest imagePullPolicy: Always name: tutorial-app ports: - containerPort: 8080 name: http protocol: TCP You will also have the image pushed to your registry. DockerHub for this example: It is possible to generate a StatefulSet resource instead of the default Deployment resource via the application.properties; quarkus.kubernetes.deployment-kind=StatefulSet Now deploy the application to your Kubernetes cluster using any of the two manifests. For example: kubectl apply -f target/kubernetes/kubernetes.yml Verify if the deployment is up: # kubectl get deploy NAME READY UP-TO-DATE AVAILABLE AGE tutorial-app 1/1 1 1 13s

# kubectl get pods NAME READY STATUS RESTARTS AGE tutorial-app-bc774dc8d-k494g 1/1 Running 0 19s Check if the service is running: # kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 443/TCP 31m tutorial-app LoadBalancer 10.102.87.114 80:30400/TCP 4m53s Access the deployment using the provided port 30400. This can be done using a web browser with the URL http://IP_Address:30400/hello Or from the terminal as shown: $ curl 192.168.205.4:30400/hello Hello from RESTEasy Reactive This is the output of the file at src/main/java/org/acme/GreetingResource.java 4. Tuning the generated resources using application.properties Quarkus allows one to tune the generated manifest using the application.properties file. Through this file, several configurations can be made. These include: A. Namespace Quarkus allows one to run the application in a chosen namespace. It omits the namespace in the generated manifest rather than enforcing it in the default namespace. Therefore, you can run the application in the desired namespace say test using the command: kubectl apply -f target/kubernetes/kubernetes.yml -n=test Aside from specifying the namespace when running the Kubernetes command, you can still capture the namespace in the application.properties as shown: quarkus.kubernetes.namespace=mynamespace Replace mynamespace with the desired namespace for the application. B. Defining a Docker registry There are several other registries that can be defined. If left undefined, docker.io is used. If you want ot use another registry such as quay.io, then you need to specify it: quarkus.container-image.registry=my.docker-registry.net my.docker-registry.net is the registry you want to use. C. Environment variables There are several ways of defining variables on Kubernetes. These includes: key/value pairs import all values from a Secret or ConfigMap interpolate a single value identified by a given field in a Secret or ConfigMap interpolate a value from a field within the same resource Environment variables from key/value pairs To add environment variables from key/value pairs, use the below syntax: quarkus.kubernetes.env.vars.my-env-var=foobar This adds MY_ENV_VAR=foobar as an environment variable. my-env-var is converted to uppercase and the dashes are replaced with underscores to result in MY_ENV_VAR. Environment variables from Secret To add key/value pairs of Secret as environment variables, add the lines below to application.properties: quarkus.kubernetes.env.secrets=my-secret,my-other-secret This will result in the following in the container environment: envFrom: - secretRef: name: my-secret optional: false - secretRef: name: my-other-secret optional: false You can set the variable by extracting a value defined by keyName form the my-secret: quarkus.kubernetes.env.mapping.foo.from-secret=my-secret quarkus.kubernetes.env.mapping.foo.with-key=keyName Resulting into: - env: - name: FOO valueFrom: secretKeyRef: key: keyName name: my-secret optional: false Environment variables from ConfigMap Quarkus can be used to add key/value pairs from ConfigMap as environment variables. To achieve this, you need to add the lines below separating the ConfigMap to be used as a source by a comma. For example: quarkus.kubernetes.env.configmaps=my-config-map,another-config-map This will result into: envFrom: - configMapRef: name: my-config-map optional: false - configMapRef: name: another-config-map optional: false It is also possible to extract keyName field from the my-config-map by using: quarkus.kubernetes.env.mapping.foo.from-configmap=my-configmap quarkus.kubernetes.env.mapping.foo.with-key=keyName This will generate a manifest with the below lines:

- env: - name: FOO valueFrom: configMapRefKey: key: keyName name: my-configmap optional: false That is it! Closing Thoughts That summarizes this guide on how to deploy and use Quarkus in Kubernetes. I am sure that you are now in a position to generate the Kubernetes resources based on some defaults and the user-provided configuration using Quarkus. I hope this was valuable.

[reportwire]

Extend K8s Service Discovery With Stork/Quarkus

Extend K8s Service Discovery With Stork/Quarkus

In traditional monolithic architecture, applications already knew where the backend services existed through static hostnames, IP addresses, and ports. The IT operation team maintained the static configurations for service reliability and system stability. This Day 2 operation has significantly changed since microservices began running in distributed networking systems. The change happened…

[reportwire]

Java Serverless Functions With Quarkus Quick Start

Java Serverless Functions With Quarkus Quick Start

Are you looking for the shortest path or cheatsheet to bring your Java application into a serverless platform based on Kubernetes? Perhaps you don’t have enough time to stand up relevant infrastructure and configure settings for both the application and the platform. This article is a guide to developing Java serverless functions using a Quarkus quick start in the Developer Sandbox for Red Hat…

[reportwire]

What's New With Java 17 and Containers?

What’s New With Java 17 and Containers?

Container platforms and edge computing continue to grow, powering major networks and applications across the globe, and Java technologies have evolved new features and improved performance to match steps with modern infrastructure. Java 17 (OpenJDK 17) was released recently (September 2021) with the following major features: Developers are wondering how to start implementing application logic…

[codecraftshop]

Watch "Introduction to quarkus - quarkus tutorial | quarkus for beginners | CodeCraftShop" on YouTube

Watch “Introduction to quarkus – quarkus tutorial | quarkus for beginners | CodeCraftShop” on YouTube

[holytheoristtastemaker]

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwMIHO1

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwMIHO1

— Damian Fallon (@DamianFallon2) March 19, 2020

from Twitter https://twitter.com/DamianFallon2

[holytheoristtastemaker]

Digital Tutorials: Quarkus https://t.co/Qiq1usWTgn fixes bugs in the Kubernetes N... https://t.co/PDN9wLLDSW

Digital Tutorials: Quarkus https://t.co/Qiq1usWTgn fixes bugs in the Kubernetes N... https://t.co/PDN9wLLDSW

— Damian Fallon (@DamianFallon2) March 18, 2020

from Twitter https://twitter.com/DamianFallon2

[holytheoristtastemaker]

Digital Tutorials: Quarkus https://t.co/Qiq1usWTgn fixes bugs in the Kubernetes N... https://t.co/PDN9wLLDSW

Digital Tutorials: Quarkus https://t.co/Qiq1usWTgn fixes bugs in the Kubernetes N... https://t.co/PDN9wLLDSW

— Damian Fallon (@DamianFallon2) March 17, 2020

from Twitter https://twitter.com/DamianFallon2

[holytheoristtastemaker]

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwN0jcB

Digital Tutorials: Quarkus tests with Testcontainers and PostgreSQL https://t.co/3DIfwN0jcB

— Damian Fallon (@DamianFallon2) March 16, 2020

from Twitter https://twitter.com/DamianFallon2