Posts from 2019

Understanding the network plumbing that makes Kubernetes pods and services work

kubernetesOct 14, 2019 4 min read

This morning I wanted to better understand how requests to ClusterIPs get routed to Kubernetes pods. Properly functioning networking is critical to Kubernetes and having a solid understanding of what happens under the covers makes debugging problems much, much easier. To get started with my studies I fired up five kuard pods: I created 5 pods so one would hopefully be placed on each worker node. Once the pods finished creating I exposed the pods to the cluster with the kubectl expose command: Behind the scenes kube-proxy uses iptables-save and iptables-restore to add rules…

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How to easily create a JSON file from a YAML file

webOct 5, 2019 2 min

If you work with with modern orchestration and configuration management systems you are most likely dealing with YAML and JSON on a daily basis. During testing, it is periodically useful to convert between these two formats, especially when interacting directly with API gateways. The yq Go program makes this incredibly easy and it has become a staple in my utility belt! To get started with yq you can snag it from github: Once downloaded you can review the available options by running yq without any arguments: The yq project was started to provide a tool that worked like jq but operates on YAML instead of JSON…

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