kubernetes-diff-logger

This simple application is designed to watch Kubernetes objects and log diffs when they occur. It is designed to log changes to Kubernetes objects in a clean way for storage and processing in Loki.

Example output

{"timestamp":"2022-10-06T08:34:30Z","verb":"updated","kind":"Deployment","notes":".spec.replicas: 1 -> 2","name":"podinfo","namespace":"default"}
{"timestamp":"2022-10-06T08:35:47Z","verb":"updated","kind":"Deployment","notes":".spec.template.spec.containers[0].env[1]: map[name:NEW_ENV_KEY value:newEnvValue] (added)","name":"podinfo","namespace":"default"}

See Deployment for example yaml to deploy to Kubernetes. The example will monitor and log information about changes in all namespaces.

Usage

Usage of ./kubernetes-diff-logger:
  -config string
    	Path to config file.  Required.
  -kubeconfig string
    	Path to a kubeconfig. Only required if out-of-cluster.
  -log-added
    	Log when deployments are added.
  -log-deleted
    	Log when deployments are deleted.
  -master string
    	The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.
  -namespace string
    	Filter updates by namespace.  Leave empty to watch all.
  -resync duration
    	Periodic interval in which to force resync objects. (default 30s)

Config File

differs:
  - resource: "deployment"
    matchRegex: "want-to-log"
    ignoreRegex: "want-to-(ignore|exclude)"
  - resource: "configmap"
  - resource: "mycustomresource"
commonLabelConfig:
  enable: true
  ignoreKeys:
    - untracked-label-key
commonAnnotationConfig:
  enable: true
  ignoreKeys:
    - untracked-annotation-key

Field	Type	Description
differs.resource	string	Name of Kubernetes resource type that you want to log diff.
differs.matchRegexp	string	Regexp for resource name to log. (If blank, log all)
differs.ignoreRegexp	string	Regexp for resource name to not log. (Priority over matchRegexp)
commonLabelConfig.enable	boolean	Whether to log metadata.labels diff.
commonLabelConfig.ignoreKeys	[]string	Key of labels that do not log diff. (exact match)
commonAnnotationConfig.enable	boolean	Whether to log metadata.annotations diff.
commonAnnotationConfig.ignoreKeys	[]string	Key of annotations that do not log diff. (exact match)