uejb / kubernetes-kafka

Kafka cluster as Kubernetes StatefulSet, plain manifests and config

Kafka for Kubernetes

This community seeks to provide:

• Production-worthy Kafka setup for persistent (domain- and ops-) data at small scale.
• Operational knowledge, biased towards resilience over throughput, as Kubernetes manifest.
• A platform for event-driven (streaming!) microservices design using Kubernetes.

To quote @arthurk:

thanks for creating and maintaining this Kubernetes files, they're up-to-date (unlike the kubernetes contrib files, don't require helm and work great!

Getting started

We suggest you apply -f manifests in the following order:

• namespace
• ./rbac-namespace-default
• ./zookeeper
• ./kafka

That'll give you client "bootstrap" bootstrap.kafka.svc.cluster.local:9092.

Fork

Our only dependency is kubectl. Not because we dislike Helm or Operators, but because we think plain manifests make it easier to collaborate. If you begin to rely on this kafka setup we recommend you fork, for example to edit broker config.

Kustomize

With the introduction of app customization in kubectl 1.14 there's an alternative to forks. We as a community can maintain a set of overlays.

See the variants folder for different overlays. For example to scale to 1 kafka broker try kubectl apply -k variants/scale-1/. Variants also include examples of how to configure volumes for GKE, AWS and AKS with different storage classes.

Quickstart

kubectl create namespace kafka && \
kubectl apply -k github.com/Yolean/kubernetes-kafka/variants/dev-small/?ref=v6.0.3

When all pods are Ready, test with for example kafkacat -b localhost:9094 -L over kubectl -n kafka port-forward kafka-0 9094.

Maintaining your own kustomization

Start your variant as a new folder in your choice of version control, with a base kustomization.yaml pointing to a tag or revision in this repository:

bases:
- github.com/Yolean/kubernetes-kafka/rbac-namespace-default/?ref=60d01b5
- github.com/Yolean/kubernetes-kafka/kafka/?ref=60d01b5
- github.com/Yolean/kubernetes-kafka/zookeeper/?ref=60d01b5

Then pick and chose from patches our example variants to tailor your Kafka setup.

Version history

tag	k8s ≥	highlights
v7.0.0	1.15+	Breaking with nonroot and native bases
v6.0.x	1.13+	Kafka 2.4.0 + standard storage class
v6.0.0	1.11+	Kafka 2.2.0 + apply -k (kubectl 1.14+) + #270
v5.1.0	1.11+	Kafka 2.1.1
v5.0.3	1.11+	Zookeeper fix #227 + maxClientCnxns=1
v5.0	1.11+	Destabilize because in Docker we want Java 11 #197 #191
v4.3.1	1.9+	Critical Zookeeper persistence fix #228
v4.3	1.9+	Adds a proper shutdown hook #207
v4.2	1.9+	Kafka 1.0.2 and tools upgrade
		... see releases for full history ...
v1.0	1	Stateful? In Kubernetes? In 2016? Yes.

Monitoring

Have a look at:

• ./prometheus
• ./linkedin-burrow
• ./consumers-prometheus
• or plain JMX
• what's happening in the monitoring label.
• Note that this repo is intentionally light on automation. We think every SRE team must build the operational knowledge first. But there is an example of a Cruise Control setup.

Outside (out-of-cluster) access

Available for:

• Brokers

Stream...

• Kubernetes events to Kafka
• Container logs to Kafka
• Heapster metrics to Kafka