In a previous article, I provided a full step-by-step example of creating and running a Spring Boot web application that was packaged as a Docker image and run using the local Docker daemon. In this article, I want to focus on the same Spring Boot REST web application, but without using Docker. Instead we will … Java: creating OCI-compatible image for Spring Boot web using buildah
buildah is a tool that can create OCI compatible (Docker) images without the Docker daemon. podman can run these images without the need for a Docker daemon. The buildah and podman packages are available on the Debian Bullseye testing branch, but are not available from an Ubuntu 20.04 LTS release because these test packages could … Buildah: Installing buildah and podman on Ubuntu 20.04
While working on your Spring Boot web application locally, gradle provides the ‘bootRun’ for a quick development lifecycle and ‘bootJar’ for packaging all the dependencies as a single jar deliverable. But for most applications these days, you will need this packaged into an OCI compatible (i.e. Docker) image for its ultimate deployment to an orchestrator … Java: Creating Docker image for Spring Boot web app using gradle
No matter how highly available your services, there may still be significant backend events that require planned maintenance. During this downtime, you should still reply to end users and service integrations with a proper response. In this article, I will show you how to configure your GCP HTTPS Loadbalancer so that a single maintenance service … GCP: serving a maintenance page using an HTTPS LB and container native routing
If you are in the development lifecycle and need to quickly test email functionality, you can deploy the codecentric/mailhog image directly within Kubernetes. It will receive all email regardless of address, and from its web interface show you all the email that has been received. In this article, I will show you how to deploy … Kubernetes: running a mail container for testing email during development
The Kubernetes Downward API allows a pod to get access to metadata about itself and the cluster without creating a tight coupling to the Kubernetes API. For example, information such as pod name, labels, annotations, IP address, node, and cpu/memory limits can be made available inside the pod. In this article, I’ll show how to … Kubernetes: using the Downward API to access pod/container metadata
In a previous article I discussed the advantages to keeping container images in the private Google Container Registry of a project. And if you have a GKE cluster in the exact same project, then image pulls happen seamlessly without any additional configuration required. However, if the GKE cluster is in a different project than the … GCP: pulling an image from the Container Registry of another project
Whether you are running a docker daemon on a development host or a GKE worker node using Docker as the container engine, it is important to understand the amount of disk storage being utilized by the containers. If you navigate into the ‘/var/lib/docker/overlay2’ directory, you will see cryptic hashed ids representing the containers layers instead … Docker: determining container responsible for largest overlay directories
Update Jan 2022: If you would rather have a mail server running in Kubernetes, see my article here. There are many reasons you might want your own Postfix server: maybe you need to test various relay settings, or validate the ability of your mail script to use TLS, or maybe you are a developer that … Docker: Running a Postfix container for testing mail during development
Zabbix distributes Docker images for each component. Not only does this mean you can quickly standup the monitoring solution, but upgrades also become a simple matter of trading up images. In this article, I will show how to stand up and then upgrade a zabbix installation using docker-compose.
The Docker console commands for listing and viewing containers and images (ps, images, history, inspect) provides a wealth of information, but when you are managing hundreds of containers, a graph view of the container inventory and their dependencies can be critical for operations. Dockviz can help you visualize your containers and images by creating an PNG image … Docker: Visualizing image hierarchy and container dependency using dockviz