Category: Containers

How do you list all the PODs and containers in your Kubernetes cluster

To list all pods and containers use the below command kubectl get pods -o=custom-columns=POD:.metadata.name,CONTAINERS:.spec.containers[*].name To list all pods and containers in a given namespace use the below command kubectl get pods -o=custom-columns=POD:.metadata.name,CONTAINERS:.spec.containers[*].name -n <<namespace>> Output of the above command will show PODs and the containers against it in a tabular format. Details on what are … Continue reading How do you list all the PODs and containers in your Kubernetes cluster →

What is data lineage and why is it relevant?

Data lineage refers to the process of tracing the movement of data from its origin and the different stages of transformation it has to go through over a period of time before reaching its final destination. It provides a comprehensive view of the data source, its transformations, and its final destination within the data pipeline. … Continue reading What is data lineage and why is it relevant? →

How do i check logs of a docker container ?

To demonstrate this, i have a sample spring boot application which prints log every 1000 milliseconds (1 second) @RestController public class RandomLoggerResource { private static final Logger logger = LoggerFactory.getLogger(RandomLoggerResource.class); private Random random = new Random(); @Scheduled(fixedRate = 1000) public void logRandomMessage() { int randomInt = random.nextInt(); String randomMessage = "Generating a Random integer every … Continue reading How do i check logs of a docker container ? →

What are the alternatives for Kubernetes ?

The alternatives can be categorized into these 4 categories Container as a Service (CaaS): Options in this category are services like AWS Fargate and Azure Container Instances. These cloud services manage the complexity of managing containers at scale and eliminates the need for managing or running Kubernetes. Managed Kubernetes services : Popular choices in this … Continue reading What are the alternatives for Kubernetes ? →

What is HELM, why do you need it & what problem does it solve for Kubernetes?

Helm is a tool which helps to manage Kubernetes applications. Deploying applications to Kubernetes is not a simple task and some of the concepts and techniques for deploying and managing applications and services has a steep learning curve. To deploy a simple spring boot application with PostgreSQL backend, explained in blog we had to write … Continue reading What is HELM, why do you need it & what problem does it solve for Kubernetes? →

Can i copy files from host to container and from container to host ? If so, how can i do it ?

Yes, you can copy files from host to container and from container to host. The docker cp utility copies the contents of source to the destination. You can copy from the container’s file system to the local machine or the reverse, from the local filesystem to the container. Localhost --> Container docker cp <path of … Continue reading Can i copy files from host to container and from container to host ? If so, how can i do it ? →

What are secrets in Kubernetes & how do you use it ?

A Secret object in kubernetes contains sensitive data such as client secret, password, token or a key. Secrets provide a way to store these sensitive informations separately from Pod definitions or container images. Since these secret objects can be created independently from Pod, there is a less risk of these information being exposed during the … Continue reading What are secrets in Kubernetes & how do you use it ? →

Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 1

How to deploy a containerized spring boot application , with PostgreSQL as database on minikube. This post will also share details on how to initialize the database with tables and data during the initialization process. Will use a spring boot application order service with a REST endpoint to fetch customer details GET /customers It uses … Continue reading Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 1 →

How do you give arguments to a docker container? What is CMD & ENTRYPOINT in a docker file ?

If you want to build a docker container which takes argument or needs an argument at the startup , how do you do that ? Example: We have a java program , which adds two number and we want users to pass arguments when they do docker run.. so how do we accomplish that when … Continue reading How do you give arguments to a docker container? What is CMD & ENTRYPOINT in a docker file ? →

Why is POD the smallest deployable unit in Kubernetes and not containers??

Kubernetes does not work directly with containers, it uses POD as the smallest deployable unit.A container contains all our application code and its dependencies packaged as a single unit, but in order for Kubernetes to run and manage these containers, it needs additional features, for example restart policy which defines what to do with a … Continue reading Why is POD the smallest deployable unit in Kubernetes and not containers?? →