├── LICENSE ├── README.md ├── cassandra-peer-service.yml ├── cassandra-replication-controller.yml ├── cassandra-service.yml ├── cassandra-status.sh ├── image ├── Dockerfile ├── README.md ├── build.sh └── custom-entrypoint.sh └── start-cassandra.sh /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. Definitions. 8 | 9 | "License" shall mean the terms and conditions for use, reproduction, 10 | and distribution as defined by Sections 1 through 9 of this document. 11 | 12 | "Licensor" shall mean the copyright owner or entity authorized by 13 | the copyright owner that is granting the License. 14 | 15 | "Legal Entity" shall mean the union of the acting entity and all 16 | other entities that control, are controlled by, or are under common 17 | control with that entity. For the purposes of this definition, 18 | "control" means (i) the power, direct or indirect, to cause the 19 | direction or management of such entity, whether by contract or 20 | otherwise, or (ii) ownership of fifty percent (50%) or more of the 21 | outstanding shares, or (iii) beneficial ownership of such entity. 22 | 23 | "You" (or "Your") shall mean an individual or Legal Entity 24 | exercising permissions granted by this License. 25 | 26 | "Source" form shall mean the preferred form for making modifications, 27 | including but not limited to software source code, documentation 28 | source, and configuration files. 29 | 30 | "Object" form shall mean any form resulting from mechanical 31 | transformation or translation of a Source form, including but 32 | not limited to compiled object code, generated documentation, 33 | and conversions to other media types. 34 | 35 | "Work" shall mean the work of authorship, whether in Source or 36 | Object form, made available under the License, as indicated by a 37 | copyright notice that is included in or attached to the work 38 | (an example is provided in the Appendix below). 39 | 40 | "Derivative Works" shall mean any work, whether in Source or Object 41 | form, that is based on (or derived from) the Work and for which the 42 | editorial revisions, annotations, elaborations, or other modifications 43 | represent, as a whole, an original work of authorship. For the purposes 44 | of this License, Derivative Works shall not include works that remain 45 | separable from, or merely link (or bind by name) to the interfaces of, 46 | the Work and Derivative Works thereof. 47 | 48 | "Contribution" shall mean any work of authorship, including 49 | the original version of the Work and any modifications or additions 50 | to that Work or Derivative Works thereof, that is intentionally 51 | submitted to Licensor for inclusion in the Work by the copyright owner 52 | or by an individual or Legal Entity authorized to submit on behalf of 53 | the copyright owner. For the purposes of this definition, "submitted" 54 | means any form of electronic, verbal, or written communication sent 55 | to the Licensor or its representatives, including but not limited to 56 | communication on electronic mailing lists, source code control systems, 57 | and issue tracking systems that are managed by, or on behalf of, the 58 | Licensor for the purpose of discussing and improving the Work, but 59 | excluding communication that is conspicuously marked or otherwise 60 | designated in writing by the copyright owner as "Not a Contribution." 61 | 62 | "Contributor" shall mean Licensor and any individual or Legal Entity 63 | on behalf of whom a Contribution has been received by Licensor and 64 | subsequently incorporated within the Work. 65 | 66 | 2. Grant of Copyright License. Subject to the terms and conditions of 67 | this License, each Contributor hereby grants to You a perpetual, 68 | worldwide, non-exclusive, no-charge, royalty-free, irrevocable 69 | copyright license to reproduce, prepare Derivative Works of, 70 | publicly display, publicly perform, sublicense, and distribute the 71 | Work and such Derivative Works in Source or Object form. 72 | 73 | 3. Grant of Patent License. Subject to the terms and conditions of 74 | this License, each Contributor hereby grants to You a perpetual, 75 | worldwide, non-exclusive, no-charge, royalty-free, irrevocable 76 | (except as stated in this section) patent license to make, have made, 77 | use, offer to sell, sell, import, and otherwise transfer the Work, 78 | where such license applies only to those patent claims licensable 79 | by such Contributor that are necessarily infringed by their 80 | Contribution(s) alone or by combination of their Contribution(s) 81 | with the Work to which such Contribution(s) was submitted. If You 82 | institute patent litigation against any entity (including a 83 | cross-claim or counterclaim in a lawsuit) alleging that the Work 84 | or a Contribution incorporated within the Work constitutes direct 85 | or contributory patent infringement, then any patent licenses 86 | granted to You under this License for that Work shall terminate 87 | as of the date such litigation is filed. 88 | 89 | 4. Redistribution. You may reproduce and distribute copies of the 90 | Work or Derivative Works thereof in any medium, with or without 91 | modifications, and in Source or Object form, provided that You 92 | meet the following conditions: 93 | 94 | (a) You must give any other recipients of the Work or 95 | Derivative Works a copy of this License; and 96 | 97 | (b) You must cause any modified files to carry prominent notices 98 | stating that You changed the files; and 99 | 100 | (c) You must retain, in the Source form of any Derivative Works 101 | that You distribute, all copyright, patent, trademark, and 102 | attribution notices from the Source form of the Work, 103 | excluding those notices that do not pertain to any part of 104 | the Derivative Works; and 105 | 106 | (d) If the Work includes a "NOTICE" text file as part of its 107 | distribution, then any Derivative Works that You distribute must 108 | include a readable copy of the attribution notices contained 109 | within such NOTICE file, excluding those notices that do not 110 | pertain to any part of the Derivative Works, in at least one 111 | of the following places: within a NOTICE text file distributed 112 | as part of the Derivative Works; within the Source form or 113 | documentation, if provided along with the Derivative Works; or, 114 | within a display generated by the Derivative Works, if and 115 | wherever such third-party notices normally appear. The contents 116 | of the NOTICE file are for informational purposes only and 117 | do not modify the License. You may add Your own attribution 118 | notices within Derivative Works that You distribute, alongside 119 | or as an addendum to the NOTICE text from the Work, provided 120 | that such additional attribution notices cannot be construed 121 | as modifying the License. 122 | 123 | You may add Your own copyright statement to Your modifications and 124 | may provide additional or different license terms and conditions 125 | for use, reproduction, or distribution of Your modifications, or 126 | for any such Derivative Works as a whole, provided Your use, 127 | reproduction, and distribution of the Work otherwise complies with 128 | the conditions stated in this License. 129 | 130 | 5. Submission of Contributions. Unless You explicitly state otherwise, 131 | any Contribution intentionally submitted for inclusion in the Work 132 | by You to the Licensor shall be under the terms and conditions of 133 | this License, without any additional terms or conditions. 134 | Notwithstanding the above, nothing herein shall supersede or modify 135 | the terms of any separate license agreement you may have executed 136 | with Licensor regarding such Contributions. 137 | 138 | 6. Trademarks. This License does not grant permission to use the trade 139 | names, trademarks, service marks, or product names of the Licensor, 140 | except as required for reasonable and customary use in describing the 141 | origin of the Work and reproducing the content of the NOTICE file. 142 | 143 | 7. Disclaimer of Warranty. Unless required by applicable law or 144 | agreed to in writing, Licensor provides the Work (and each 145 | Contributor provides its Contributions) on an "AS IS" BASIS, 146 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 147 | implied, including, without limitation, any warranties or conditions 148 | of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A 149 | PARTICULAR PURPOSE. You are solely responsible for determining the 150 | appropriateness of using or redistributing the Work and assume any 151 | risks associated with Your exercise of permissions under this License. 152 | 153 | 8. Limitation of Liability. In no event and under no legal theory, 154 | whether in tort (including negligence), contract, or otherwise, 155 | unless required by applicable law (such as deliberate and grossly 156 | negligent acts) or agreed to in writing, shall any Contributor be 157 | liable to You for damages, including any direct, indirect, special, 158 | incidental, or consequential damages of any character arising as a 159 | result of this License or out of the use or inability to use the 160 | Work (including but not limited to damages for loss of goodwill, 161 | work stoppage, computer failure or malfunction, or any and all 162 | other commercial damages or losses), even if such Contributor 163 | has been advised of the possibility of such damages. 164 | 165 | 9. Accepting Warranty or Additional Liability. While redistributing 166 | the Work or Derivative Works thereof, You may choose to offer, 167 | and charge a fee for, acceptance of support, warranty, indemnity, 168 | or other liability obligations and/or rights consistent with this 169 | License. However, in accepting such obligations, You may act only 170 | on Your own behalf and on Your sole responsibility, not on behalf 171 | of any other Contributor, and only if You agree to indemnify, 172 | defend, and hold each Contributor harmless for any liability 173 | incurred by, or claims asserted against, such Contributor by reason 174 | of your accepting any such warranty or additional liability. 175 | 176 | END OF TERMS AND CONDITIONS 177 | 178 | APPENDIX: How to apply the Apache License to your work. 179 | 180 | To apply the Apache License to your work, attach the following 181 | boilerplate notice, with the fields enclosed by brackets "{}" 182 | replaced with your own identifying information. (Don't include 183 | the brackets!) The text should be enclosed in the appropriate 184 | comment syntax for the file format. We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright {yyyy} {name of copyright owner} 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | 203 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Multi-node [Cassandra](http://cassandra.apache.org) Cluster on [Kubernetes](http://kubernetes.io/) 2 | 3 | ## Creating a Cluster 4 | 5 | You will need to bring your own Kubernetes. A quick and easy way to setup Kubernetes locally is [via Docker Compose](https://github.com/vyshane/docker-compose-kubernetes). Once you have Kubernetes up and running: 6 | 7 | ```sh 8 | ./start-cassandra.sh 9 | ``` 10 | 11 | This will create a Kubernetes pod containing a single Cassandra node. You can use the [`cassandra-status.sh`](cassandra-status.sh) convenience script to see that the node comes up: 12 | 13 | ```sh 14 | ./cassandra-status.sh 15 | 16 | C* Node Kubernetes Pod 17 | ------- -------------- 18 | NAME READY STATUS RESTARTS AGE 19 | Up|Normal cassandra-kxa18 1/1 Running 0 1m 20 | ``` 21 | 22 | ## Scaling the Cluster 23 | 24 | To launch more Cassandra nodes and have them join the cluster, simply scale the [Cassandra replication controller](cassandra-replication-controller.yml): 25 | 26 | ```sh 27 | kubectl scale rc cassandra --replicas=2 28 | ``` 29 | 30 | A new pod is created... 31 | 32 | ```sh 33 | ./cassandra-status.sh 34 | 35 | C* Node Kubernetes Pod 36 | ------- -------------- 37 | NAME READY STATUS RESTARTS AGE 38 | cassandra-cnvzm 0/1 Image: vyshane/cassandra is ready, container is creating 0 8s 39 | Up|Normal cassandra-kxa18 1/1 Running 0 6m 40 | ``` 41 | 42 | ... and it automatically joins the cluster. 43 | 44 | ```sh 45 | ./cassandra-status.sh 46 | 47 | C* Node Kubernetes Pod 48 | ------- -------------- 49 | NAME READY STATUS RESTARTS AGE 50 | Up|Joining cassandra-cnvzm 1/1 Running 0 29s 51 | Up|Normal cassandra-kxa18 1/1 Running 0 7m 52 | ``` 53 | 54 | ```sh 55 | ./cassandra-status.sh 56 | 57 | C* Node Kubernetes Pod 58 | ------- -------------- 59 | NAME READY STATUS RESTARTS AGE 60 | Up|Normal cassandra-cnvzm 1/1 Running 0 1m 61 | Up|Normal cassandra-kxa18 1/1 Running 0 8m 62 | ``` 63 | 64 | ## Connecting to Cassandra 65 | 66 | You can connect to Cassandra from any pod in the Kubernetes cluster via the IP address of the [Cassandra service](cassandra-service.yml). To obtain the IP address: 67 | 68 | ```sh 69 | kubectl describe svc cassandra 70 | ``` 71 | 72 | If the [Kubernetes DNS addon](https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dns) is active, you can also connect to the service through the `cassandra` hostname. 73 | 74 | ## Configuration Options 75 | 76 | The following environment variables can be configured in the [Cassandra replication controller definition](cassandra-replication-controller.yml): 77 | 78 | ```sh 79 | env: 80 | - name: CASSANDRA_CLUSTER_NAME 81 | value: Cassandra 82 | - name: CASSANDRA_DC 83 | value: DC1 84 | - name: CASSANDRA_RACK 85 | value: Kubernetes Cluster 86 | - name: CASSANDRA_ENDPOINT_SNITCH 87 | value: GossipingPropertyFileSnitch 88 | ``` 89 | 90 | ## Alternatives? 91 | 92 | The Kubernetes project has a [Cassandra example](https://github.com/kubernetes/kubernetes/tree/master/examples/cassandra) that uses a custom seed provider for seed discovery. The example makes use of a Cassandra Docker image from `gcr.io/google_containers`. 93 | 94 | ## Why Did You Create this Project? 95 | 96 | I wanted a solution based on the [official Cassandra Docker image](https://hub.docker.com/_/cassandra/). My [Docker image](image/) extends the official Cassandra image with the addition of [dnsutils](https://packages.debian.org/jessie/dnsutils) (for the `dig` command) and a [custom entrypoint](image/custom-entrypoint.sh) that configures seed nodes for the container. Seed node IP addresses are provided via DNS by a [headless Kubernetes service](cassandra-peer-service.yml). 97 | 98 | ## Next Steps 99 | 100 | * [Configure Cassandra to use authentication](http://docs.datastax.com/en/cassandra/2.2/cassandra/configuration/secureConfigNativeAuth.html) 101 | -------------------------------------------------------------------------------- /cassandra-peer-service.yml: -------------------------------------------------------------------------------- 1 | # Headless service that allows us to get the IP addresses of our Cassandra nodes 2 | apiVersion: v1 3 | kind: Service 4 | metadata: 5 | labels: 6 | name: cassandra-peers 7 | name: cassandra-peers 8 | spec: 9 | clusterIP: None 10 | ports: 11 | - port: 7000 12 | name: intra-node-communication 13 | - port: 7001 14 | name: tls-intra-node-communication 15 | selector: 16 | name: cassandra 17 | -------------------------------------------------------------------------------- /cassandra-replication-controller.yml: -------------------------------------------------------------------------------- 1 | apiVersion: v1 2 | kind: ReplicationController 3 | metadata: 4 | labels: 5 | name: cassandra 6 | name: cassandra 7 | spec: 8 | replicas: 1 9 | selector: 10 | name: cassandra 11 | template: 12 | metadata: 13 | labels: 14 | name: cassandra 15 | spec: 16 | containers: 17 | - image: vyshane/cassandra 18 | name: cassandra 19 | env: 20 | - name: PEER_DISCOVERY_SERVICE 21 | value: cassandra-peers 22 | 23 | # Feel free to change the following: 24 | - name: CASSANDRA_CLUSTER_NAME 25 | value: Cassandra 26 | - name: CASSANDRA_DC 27 | value: DC1 28 | - name: CASSANDRA_RACK 29 | value: Kubernetes Cluster 30 | - name: CASSANDRA_ENDPOINT_SNITCH 31 | value: GossipingPropertyFileSnitch 32 | ports: 33 | - containerPort: 9042 34 | name: cql 35 | volumeMounts: 36 | - mountPath: /var/lib/cassandra/data 37 | name: data 38 | volumes: 39 | - name: data 40 | emptyDir: {} 41 | -------------------------------------------------------------------------------- /cassandra-service.yml: -------------------------------------------------------------------------------- 1 | apiVersion: v1 2 | kind: Service 3 | metadata: 4 | labels: 5 | name: cassandra 6 | name: cassandra 7 | spec: 8 | ports: 9 | - port: 9042 10 | name: cql 11 | selector: 12 | name: cassandra 13 | -------------------------------------------------------------------------------- /cassandra-status.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | # 3 | # Output Cassandra cluster and pod status 4 | 5 | find_cassandra_pods="kubectl get pods -l name=cassandra" 6 | 7 | first_running_seed=$($find_cassandra_pods --no-headers | \ 8 | grep Running | \ 9 | grep 1/1 | \ 10 | head -1 | \ 11 | awk '{print $1}') 12 | 13 | cluster_status=$(kubectl exec $first_running_seed \ 14 | -c cassandra \ 15 | -- nodetool status -r) 16 | 17 | echo 18 | echo " C* Node Kubernetes Pod" 19 | echo " ------- --------------" 20 | 21 | while read -r line; do 22 | node_name=$(echo $line | awk '{print $1}') 23 | status=$(echo "$cluster_status" | grep $node_name | awk '{print $1}') 24 | 25 | long_status=$(echo "$status" | \ 26 | sed 's/U/ Up/g' | \ 27 | sed 's/D/Down/g' | \ 28 | sed 's/N/|Normal /g' | \ 29 | sed 's/L/|Leaving/g' | \ 30 | sed 's/J/|Joining/g' | \ 31 | sed 's/M/|Moving /g') 32 | 33 | : ${long_status:=" "} 34 | 35 | echo "$long_status $line" 36 | done <<< "$($find_cassandra_pods)" 37 | 38 | echo 39 | -------------------------------------------------------------------------------- /image/Dockerfile: -------------------------------------------------------------------------------- 1 | FROM cassandra:2.2 2 | MAINTAINER Vy-Shane Xie 3 | ENV REFRESHED_AT 2015-12-23 4 | 5 | RUN apt-get -qq update && \ 6 | DEBIAN_FRONTEND=noninteractive apt-get -yq install dnsutils && \ 7 | apt-get clean && \ 8 | rm -rf /var/lib/apt/lists/* 9 | 10 | COPY custom-entrypoint.sh / 11 | ENTRYPOINT ["/custom-entrypoint.sh"] 12 | CMD ["cassandra", "-f"] 13 | -------------------------------------------------------------------------------- /image/README.md: -------------------------------------------------------------------------------- 1 | # vyshane/cassandra Docker Image 2 | 3 | Extends the [official Cassandra image](https://hub.docker.com/_/cassandra/) with the addition of [dnsutils](https://packages.debian.org/jessie/dnsutils) (for the `dig` command) and a [custom entrypoint](https://github.com/vyshane/cassandra-kubernetes/blob/master/image/custom-entrypoint.sh) to configure seed nodes for the container. 4 | 5 | Expects seed node IP addresses to be provided as DNS A records. You can provide the domain via the `PEER_DISCOVERY_SERVICE` environment variable. This seed discovery mechanism was designed to play nice with [Kubernetes headless services](http://kubernetes.io/v1.0/docs/user-guide/services.html#headless-services). 6 | -------------------------------------------------------------------------------- /image/build.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | branch=`git rev-parse --abbrev-ref HEAD` 4 | if [ "$branch" == master ]; then 5 | branch=latest 6 | fi 7 | 8 | docker build -q -t vyshane/cassandra:$branch . 9 | -------------------------------------------------------------------------------- /image/custom-entrypoint.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | # 3 | # Configure Cassandra seed nodes. 4 | 5 | # Give Kubernetes time to add the new pod to the cassandra peer discovery service before we query DNS 6 | sleep 5 7 | 8 | my_ip=$(hostname --ip-address) 9 | 10 | CASSANDRA_SEEDS=$(host $PEER_DISCOVERY_SERVICE | \ 11 | grep -v "not found" | \ 12 | grep -v "connection timed out" | \ 13 | grep -v $my_ip | \ 14 | sort | \ 15 | head -3 | \ 16 | awk '{print $4}' | \ 17 | xargs) 18 | 19 | if [ ! -z "$CASSANDRA_SEEDS" ]; then 20 | export CASSANDRA_SEEDS 21 | fi 22 | 23 | /docker-entrypoint.sh "$@" 24 | -------------------------------------------------------------------------------- /start-cassandra.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | kubectl create -f cassandra-peer-service.yml 4 | kubectl create -f cassandra-service.yml 5 | kubectl create -f cassandra-replication-controller.yml 6 | --------------------------------------------------------------------------------