Kubernetes: new section

Signed-off-by: Eduardo Silva <eduardo@treasure-data.com>

SUMMARY.md

@@ -60,6 +60,7 @@
     * [NATS](output/nats.md)
     * [Standard Output](output/stdout.md)
     * [Treasure Data](output/td.md)
+* [Kubernetes](kubernetes/README.md)
 * [Fluent Bit for Developers](development/README.md)
     * [Library API](development/library_api.md)
     * [Ingest Records Manually](development/ingest_records_manually.md)

kubernetes/README.md

@@ -0,0 +1,38 @@
+# Kubernetes
+
+![](/imgs/flb_kubernetes.png)
+
+Fluent Bit as a log forwarder is a perfect fit for Kubernetes use case. The following document describes how to deploy Fluent Bit for your log collection needs.
+
+## Concepts
+
+Before to get started is important to understand how Fluent Bit will be deployed. Kubernetes manage a cluster of _nodes_, so our log agent tool will need to run on every node to collect logs from every _POD_, for hence Fluent Bit is deployed as a DaemonSet (a POD that runs on every _node_ of the cluster).
+
+When Fluent Bit runs, it will read, parse and filter the logs of every POD and will enrich each entry with the following information (metadata):
+
+- POD Name
+- POD ID
+- Container Name
+- Container ID
+- Labels
+- Annotations
+
+To obtain these information, a built-in filter plugin called _kubernetes_ talks to the Kubernetes API Server to retrieve relevant information such as the _pod\_id_, _labels_ and _annotations_, other fields such as _pod\_name_, _container\_id_ and _container\_name_ are retrieved locally from the log file names. All of this is handled automatically, no intervention is required from a configuration aspect.
+
+> Our Kubernetes Filter plugin is fully inspired on the [Fluentd Kubernetes Metadata Filter](https://github.com/fabric8io/fluent-plugin-kubernetes_metadata_filter) written by [Jimmi Dyson](https://github.com/jimmidyson).
+
+## Getting Started
+
+The following steps assumes that you have a Kubernetes cluster running with an Elasticsearch database on it. Our default configuration assumes that your database can be reached through the DNS name _elasticsearch-logging_.
+
+Please download the Fluent Bit DaemonSet for Elasticsearch from here:
+
+- [fluent-bit-daemonset-elasticsearch.yaml](https://raw.githubusercontent.com/fluent/fluent-bit-kubernetes-daemonset/master/fluent-bit-daemonset-elasticsearch.yaml)
+
+Now your master node deploy the daemonset with:
+
+```
+$ kubectl apply -f ./fluent-bit-daemonset-elasticsearch.yaml
+```
+
+After a few seconds Fluent Bit will be running and ingesting your logs into your Elasticsearch database. If you database have a different DNS name than _elasticsearch-logging_, make sure to perform the proper adjustments to the Yaml file.