Blog: Contextual Logging in Kubernetes 1.24

Contextual Logging in Kubernetes 1.24 Structured logging Contextual logging klog enhancements Contextual logging API ktesting logger klogr Reusable output test Output flushing Various other changes logcheck Next steps Authors: Patrick Ohly (Intel) The Structured Logging Working Group has added new capabilities to the logging infrastructure in Kubernetes 1.24. This blog post explains how developers can take advantage of those to make log output more useful and how they can get involved with improving Kubernetes. The goal of structured logging is to replace C-style formatting and the resulting opaque log strings with log entries that have a well-defined syntax for storing message and parameters separately, for example as a JSON struct. When using the traditional klog text output format for structured log calls, strings were originally printed with \n escape sequences, except when embedded inside a struct. For structs, log entries could still span multiple lines, with no clean way to split the log stream into individual entries: \n I1112 14:06:35.783529 328441 structured_logging. go:51] "using InfoS" longData={Name:long Data:Multiple lines with quite a bit of text. internal:0} I1112 14:06:35.783549 328441 structured_logging. go:52] "using InfoS with\nthe message across multiple lines" int=1 stringData="long: Multiple\nlines\nwith quite a bit\nof text. " str="another value" I1112 14:06:35.783529 328441 structured_logging. go:51] "using InfoS" longData={Name:long Data:Multiple lines with quite a bit of text. internal:0} I1112 14:06:35.783549 328441 structured_logging. go:52] "using InfoS with\nthe message across multiple lines" int=1 stringData="long: Multiple\nlines\nwith quite a bit\nof text.