This document introduces using Elastic Stack to monitor Kubernetes clusters managed by Rancher. It discusses the challenges of monitoring dynamic container environments and how Elastic Stack provides solutions through Beats, Logstash, Elasticsearch, and Kibana. Specifically, it recommends deploying Filebeat and Metricbeat on Kubernetes clusters using Helm or YAML, with Elasticsearch and Kibana running outside the clusters. It also provides resources for integrating Elastic in Rancher and configuring Beats to ship logs and metrics to Elasticsearch.