Spring Boot makes it quite easy to find the Git revision of a running application. You add a Gradle plugin and the revision is added to the Actuator's info endpoint. What it doesn't do though is publish the Git revision as part of the SBOM or OCI metadata. That requires …
read moreOther articles
File Name Too Long
When trying to build the Spring Boot source code, I ran into a strange problem: The Gradle build terminated with several "File name too long" exceptions. I knew that the ext4 filesystem I was using has limits - 4064 characters for the entire path and 255 characters for each segment. But …
read moreTesting Alertmanager
When a Prometheus alerting rule fires, the Prometheus server sends a notification to the Alertmanager, which is then responsible for processing that alert further, i.e. by routing it to an appropriate alerting channel (e-mail, Slack, ...). In order to test the Alertmanager configuration, it is useful to trigger alerts directly …
read morePlaying with WebAuthn
On the internet today, our online accounts are exposed to a lot of risks. Leaked passwords from break-ins at major Internet properties or phishing attacks have lead to many account breaches. In order to protect my high-value accounts, I have either enabled two-factor authentication or I use federated sign-in, delegating …
read moreUsing Kubectl Printers and Plugins
Even though we have plenty of metrics and dashboards at work, I use the kubectl command line tool a lot for looking at resources and for troubleshooting. Because the defaults don't always display the information that I need, I often use the kubectl printer mechanisms. In many cases, this is …
read moreMonitoring Log Statements in Go
Good monitoring and alerting are essential for running services in production. As a Java developer, I'm a bit spoiled by my platform of choice, Spring Boot 2. Thanks to Micrometer it provides out of the box instrumentation for HTTP requests, data sources, caches, memory, threads, logging, and many more. When …
read moreAdditional Workspaces in Gnome
I use Gnome on Ubuntu 18.04 with static workspaces and switch between them using keyboard shortcuts - for example, ALT+1 takes me to workspace one. Unfortunately, using the graphical settings editor, I was only able to assign keyboard shortcuts to the first four workspaces. After a bit of research …
read moreRetries Can Kill You
In a large-scale distributed system, it's inevitable that some requests will fail. Even if your collaborating systems work perfectly, sooner or later you will experience temporary network issues and other intermittent errors. That's why a lot of people try to paint over this issue by implementing retries in their applications …
read morePrometheus and Spring Boot Health Checks
When trying to set up alerting for Spring Boot services with Prometheus, I discovered the synthetic "up" time series which is great for checking whether the monitoring system can reach my service instances. While this is a great thing, I also wanted to alert on the health status of my …
read more