adds chart for kafka (#144)

* adds chart for kafka

* upgrading chart to using requirements.yaml for dependencies

* updates README.md

* adds notes.txt

Adds liveness probe
Adds resource limits
Improves README.md

* adds readiness probe and removes empty dir

* ensure endpoints for all services and better testing instructions

incubator/kafka/.helmignore

@@ -0,0 +1,21 @@
+# Patterns to ignore when building packages.
+# This supports shell glob matching, relative path matching, and
+# negation (prefixed with !). Only one pattern per line.
+.DS_Store
+# Common VCS dirs
+.git/
+.gitignore
+.bzr/
+.bzrignore
+.hg/
+.hgignore
+.svn/
+# Common backup files
+*.swp
+*.bak
+*.tmp
+*~
+# Various IDEs
+.project
+.idea/
+*.tmproj

incubator/kafka/Chart.yaml

@@ -0,0 +1,17 @@
+apiVersion: v1
+description: A Kafka Helm chart for Kubernetes
+name: kafka
+version: 0.1.0
+keywords:
+  - kafka
+  - zookeeper
+  - kafka petset
+home: https://kafka.apache.org/
+sources:
+  - https://github.com/kubernetes/charts/tree/master/incubator/zookeeper
+  - https://github.com/Yolean/kubernetes-kafka
+  - https://github.com/solsson/dockerfiles/tree/master/kafka
+maintainers:
+  - name: Faraaz Khan
+    email: faraaz@rationalizeit.us
+icon: https://kafka.apache.org/images/logo.png

incubator/kafka/README.md

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+# Apache Kafka Helm Chart
+
+This is an implementation of Kafka PetSet found here:
+
+ * https://github.com/Yolean/kubernetes-kafka
+
+## Pre Requisites:
+
+* Kubernetes 1.3 with alpha APIs enabled and support for storage classes
+
+* PV support on underlying infrastructure
+
+* Requires at least `v2.0.0-beta.1` version of helm to support
+  dependency management with requirements.yaml
+
+## PetSet Details
+
+* http://kubernetes.io/docs/user-guide/petset/
+
+## PetSet Caveats
+
+* http://kubernetes.io/docs/user-guide/petset/#alpha-limitations
+
+## Chart Details
+
+This chart will do the following:
+
+* Implement a dynamically scalable kafka cluster using Kubernetes
+  PetSets
+
+* Implement a dynamically scalable zookeeper cluster as another Kubernetes PetSet required for the Kafka cluster above
+
+### Installing the Chart
+
+To install the chart with the release name `my-release` in the default
+namespace:
+
+```
+helm repo add incubator
+http://storage.googleapis.com/kubernetes-charts-incubator
+helm install --name my-kafka incubator/kafka
+```
+
+If using a dedicated namespace(recommended) then make sure the namespace
+exists with:
+
+```
+kubectl create ns kafka
+helm install --name my-kafka --set global.namespace=kafka incubator/kafka
+```
+
+This chart includes a ZooKeeper chart as a dependency to the Kafka
+cluster in its `requirement.yaml`. The chart can be customized using the
+following configurable parameters:
+
+| Parameter               | Description                        | Default                                                    |
+| ----------------------- | ---------------------------------- | ---------------------------------------------------------- |
+| `Name`                  | Kafka master name                  | `kf`                                                       |
+| `Image`                 | Kafka Container image name         | `solsson/kafka`                                            |
+| `ImageTag`              | Kafka Container image tag          | `0.10.0.1`                                                 |
+| `ImagePullPolicy`       | Kafka Container pull policy        | `Always`                                                   |
+| `Replicas`              | Kafka Brokers                      | `3`                                                        |
+| `Component`             | Kafka k8s selector key             | `kafka`                                                    |
+| `Cpu`                   | Kafka container requested cpu      | `100m`                                                     |
+| `Memory`                | Kafka container requested memory   | `512Mi`                                                    |
+| `MaxCpu`                | Kafka container cpu limit          | `200m`                                                     |
+| `MaxMemory`             | Kafka container memory limit       | `1024Mi`                                                   |
+| `DataDirectory`         | Kafka data directory               | `/opt/kafka/data`                                          |
+| `Storage`               | Kafka Persistent volume size       | `1Gi`                                                      |
+| `zookeeper.Name`        | Name of the Zookeeper Service      | `zk`                                                       |
+
+Specify parameters using `--set key=value[,key=value]` argument to `helm install`
+
+Alternatively a YAML file that specifies the values for the parameters can be provided like this:
+
+```bash
+$ helm install --name my-release -f values.yaml incubator/kafka
+```
+
+### Connecting to Kafka
+
+You can connect to Kafka by running a simple pod in the K8s cluster like this with a configuration like this:
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: testclient
+  namespace: kafka
+spec:
+  containers:
+  - name: kafka
+    image: solsson/kafka:0.10.0.1
+    command:
+      - sh
+      - -c
+      - "exec tail -f /dev/null"
+```
+
+Once you have the testclient pod above running, you can list all kafka
+topics with:
+
+` kubectl exec testclient -- ./bin/kafka-topics.sh --zookeeper
+my-release-zk:2181 --list`
+
+Where `my-release` is the name of your helm release.
+
+## Known Limitations
+
+* Namespace creation is not automated
+* Topic creation is not automated
+* Only supports storage options that have backends for persistent volume claims (tested mostly on AWS)
+* Kafka cluster is not accessible via an external endpoint

incubator/kafka/notes.txt

@@ -0,0 +1,36 @@
+You can connect to Kafka by running a simple pod in the K8s cluster like this with a configuration like this:
+
+  apiVersion: v1
+  kind: Pod
+  metadata:
+    name: testclient
+    namespace: kafka
+  spec:
+    containers:
+    - name: kafka
+      image: solsson/kafka:0.10.0.1
+      command:
+        - sh
+        - -c
+        - "exec tail -f /dev/null"
+
+  Once you have the testclient pod above running, you can list all kafka
+  topics with:
+
+  kubectl -n kafka exec testclient -- ./bin/kafka-topics.sh --zookeeper my-release-zk:2181 --list
+
+  To create a new topic:
+  kubectl -n kafka exec testclient -- ./bin/kafka-topics.sh --zookeeper my-release-zookeeper-zk:2181 --topic test1 --create --partitions 1 --replication-factor 1
+
+  To listen for messages on a topic:
+  kubectl -n kafka exec -ti testclient -- ./bin/kafka-console-consumer.sh --zookeeper my-release-zookeeper-zk:2181 --topic test1 --from-beginning
+
+  To stop the listener session above press: Ctrl+C
+
+  To start an interactive message producer session:
+  kubectl -n kafka exec -ti testclient -- ./bin/kafka-console-producer.sh --broker-list my-release-broker-kf.kafka.svc.cluster.local:9092 --topic test1
+
+  To create a message in the above session, simply type the message and press "enter"
+  To end the producer session try: Ctrl+C
+
+  Where my-release is the name of your helm release.

incubator/kafka/requirements.lock

@@ -0,0 +1,6 @@
+dependencies:
+- name: zookeeper
+  repository: http://storage.googleapis.com/kubernetes-charts-incubator
+  version: 0.1.1
+digest: sha256:8210ab022b7aaac63d45df4db7deb770bf08c5d7e24c924764648c55be5e0905
+generated: 2016-10-23T22:25:39.161124014-05:00

incubator/kafka/requirements.yaml

@@ -0,0 +1,4 @@
+dependencies:
+- name: zookeeper
+  version: 0.1.1
+  repository: http://storage.googleapis.com/kubernetes-charts-incubator

incubator/kafka/templates/kafka-petset.yaml

@@ -0,0 +1,129 @@
+---
+# headless service for petset DNS
+apiVersion: v1
+kind: Service
+metadata:
+  name: "{{ printf "%s-zookeeper-%s" .Release.Name .Values.zookeeper.Name | trunc 63 }}"
+spec:
+  ports:
+  - port: 2181
+    name: client
+  selector:
+    component: "{{.Release.Name}}-{{.Values.zookeeper.Component}}"
+
+# A headless service to create DNS records
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: "{{ printf "%s-broker-%s" .Release.Name .Values.Name | trunc 63 }}"
+  labels:
+    heritage: {{.Release.Service | quote }}
+    release: {{.Release.Name | quote }}
+    chart: "{{.Chart.Name}}-{{.Chart.Version}}"
+    component: "{{.Release.Name}}-{{.Values.Component}}"
+  annotations:
+    "helm.sh/created": {{.Release.Time.Seconds | quote }}
+    service.alpha.kubernetes.io/tolerate-unready-endpoints: "true"
+spec:
+  ports:
+  - port: 9092
+  clusterIP: None
+  selector:
+    component: "{{.Release.Name}}-{{.Values.Component}}"
+    app: kafka
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: "{{ printf "%s-%s" .Release.Name .Values.Name | trunc 63 }}"
+  labels:
+    heritage: {{.Release.Service | quote }}
+    release: {{.Release.Name | quote }}
+    chart: "{{.Chart.Name}}-{{.Chart.Version}}"
+    component: "{{.Release.Name}}-{{.Values.Component}}"
+  annotations:
+    "helm.sh/created": {{.Release.Time.Seconds | quote }}
+spec:
+  ports:
+  - port: 9092
+  selector:
+    component: "{{.Release.Name}}-{{.Values.Component}}"
+    app: kafka
+---
+apiVersion: apps/v1alpha1
+kind: PetSet
+metadata:
+  name: "{{ printf "%s-%s" .Release.Name .Values.Name | trunc 63 }}"
+  labels:
+    app: kafka
+    heritage: {{.Release.Service | quote }}
+    release: {{.Release.Name | quote }}
+    chart: "{{.Chart.Name}}-{{.Chart.Version}}"
+    component: "{{.Release.Name}}-{{.Values.Component}}"
+  annotations:
+    "helm.sh/created": {{.Release.Time.Seconds | quote }}
+spec:
+  serviceName: "{{ printf "%s-broker-%s" .Release.Name .Values.Name | trunc 63 }}"
+  replicas: {{ default 3 .Values.Replicas }}
+  template:
+    metadata:
+      labels:
+        app: kafka
+        component: "{{.Release.Name}}-{{.Values.Component}}"
+      annotations:
+        pod.alpha.kubernetes.io/initialized: "true"
+        pod.alpha.kubernetes.io/init-containers: '[
+        ]'
+    spec:
+      containers:
+      - name: "{{ printf "%s-broker-%s" .Release.Name .Values.Name | trunc 63 }}"
+        image: "{{.Values.Image}}:{{.Values.ImageTag}}"
+        imagePullPolicy: "{{.Values.ImagePullPolicy}}"
+        livenessProbe:
+          exec:
+            command:
+              - bin/kafka-topics.sh
+              - --zookeeper
+              - "{{ printf "%s-%s" .Release.Name .Values.zookeeper.Name | trunc 63 }}:2181"
+              - --list
+          initialDelaySeconds: 30
+          timeoutSeconds: 5
+        name: liveness
+        readinessProbe:
+          exec:
+            command:
+              - bin/kafka-topics.sh
+              - --zookeeper
+              - "{{ printf "%s-%s" .Release.Name .Values.zookeeper.Name | trunc 63 }}:2181"
+              - --list
+          initialDelaySeconds: 30
+          timeoutSeconds: 5
+        name: readiness
+        ports:
+        - containerPort: 9092
+          name: kafka
+        resources:
+          limits:
+            cpu: "{{ .Values.MaxCpu }}"
+            memory: "{{ .Values.MaxMemory }}"
+          requests:
+            cpu: "{{ .Values.Cpu }}"
+            memory: "{{ .Values.Memory }}"
+        command:
+        - sh
+        - -c
+        - "./bin/kafka-server-start.sh config/server.properties --override zookeeper.connect={{ printf "%s-%s" .Release.Name .Values.zookeeper.Name | trunc 63 }}:2181/ --override broker.id=${HOSTNAME##*-}"
+        volumeMounts:
+        - name: datadir
+          mountPath: "{{ .Values.DataDirectory }}"
+  volumeClaimTemplates:
+  - metadata:
+      name: datadir
+      annotations:
+        volume.alpha.kubernetes.io/storage-class: anything
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: {{.Values.Storage}}

incubator/kafka/values.yaml

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+Name: "kf"
+Replicas: 3
+Image: "solsson/kafka"
+ImageTag: "0.10.0.1"
+ImagePullPolicy: "Always"
+Cpu: "100m"
+Memory: "512Mi"
+MaxCpu: "200m"
+MaxMemory: "1024Mi"
+Storage: "1Gi"
+DataDirectory: "/opt/kafka/data"
+Component: "kafka"
+
+zookeeper:
+  Name: "zk"
+  Component: "zk"