K8s Event listener

Listen for changes on specified resources and invokes the callback script

Currently supporting:

• certificatesigningrequests
• cronjobs
• ingresses
• pods
• serviceaccounts
• nodes

Usage

$ k8s-event-listener --help
Listen for specific kubernetes events

Usage:
  k8s-event-listener [flags]

Flags:
  -c, --callback string       Callback to be executed
  -h, --help                  help for k8s-event-listener
      --kube-config string    Path to kubeconfig file
      --kube-context string   Context to use
  -p, --probe-port string     HTTP port to listen for liveness/readiness probes (default "8080")
  -r, --resource string       K8s resource to listen
  -v, --verbose string        Verbose level (default "0")

This application has been designed to live inside the cluster, it uses the injected service-account tokens to interact with the API. Optionally can be executed from outside the cluster, --kube-config and --kube-context are mandatory on those cases.

Matching resource events will be sent to callback script as arguments:

• resourceType
• action (add, update or delete)
• namespace
• name

Is important to mention that this application uses a cache system that needs to be populated, so during bootstrap, all matching resources will be evaluated as insertions.

Healthcheck

An HTTP server will be created listening to 8080 (can be overwritten via -p flag) with two available probe URLs

• /live to be used in the liveness configuration
• /ready to be used in the readiness configuration

Currently only checks for kube-api connectivity.

Example

$ k8s-event-listener -r pod -c ./test.sh

Script will start receiving instructions like:

pods add instapro-client ic-nl-tests-acc-26937c1b-webserver-7ff884c575-dvwkb
pods add instapro-gd-city-filter r-travaux-com-db-queue-worker-7585fd84c-4gxzc
pods add monitoring datadog-5swgj