mirror of
https://github.com/helm/charts.git
synced 2026-08-23 22:37:45 +00:00
Christian Budde Christensen
3bb5fc517b
Update proxy service annotations to follow the format specified in the README and values.
133 lines
6.7 KiB
Markdown
133 lines
6.7 KiB
Markdown
# RethinkDB 2.3.5 Helm Chart
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## Prerequisites Details
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* Kubernetes 1.5+ with Beta APIs enabled.
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* PV support on the underlying infrastructure.
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## StatefulSet Details
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* https://kubernetes.io/docs/concepts/abstractions/controllers/statefulsets/
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## StatefulSet Caveats
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* https://kubernetes.io/docs/concepts/abstractions/controllers/statefulsets/#limitations
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## Acknowledgment of Previous Works
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I have heavily borrowed and extended code (peer discovery and probe) from the following project to build this Helm Chart and Docker image: https://github.com/rosskukulinski/kubernetes-rethinkdb-cluster
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## Chart Details
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This chart implements a dynamically scalable [RethinkDB Cluster](https://www.rethinkdb.com/docs/sharding-and-replication/) using Kubernetes StatefulSets.
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## Installing the Chart
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To install the chart with the release name `my-release`:
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```console
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$ helm install --name my-release stable/rethinkdb
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```
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## Configuration
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The following table lists the configurable parameters of the rethinkdb chart and their default values.
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Parameter | Description | Default
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---|---|---
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`image.name` | Custom RethinkDB image name for auto-joining and probe | `codylundquist/helm-rethinkdb-cluster`
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`image.tag` | Custom RethinkDB image tag | `0.1.0`
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`image.pullPolicy` | Custom RethinkDB image pull policy | `IfNotPresent`
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`cluster.replicas` | Number of RethinkDB Cluster replicas | `3`
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`cluster.resources` | Resource configuration for each RethinkDB Cluster Pod | `{}`
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`cluster.podAnnotations` | Annotations to be added to RethinkDB Cluster Pods | `{}`
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`cluster.service.annotations` | Annotations to be added to RethinkDB Cluster Service | `{}`
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`cluster.storageClass.enabled` | If `true`, create a StorageClass for the cluster. **Note**: You must set a provisioner | `false`
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`cluster.storageClass.provisioner` | Provisioner definition for StorageClass | `undefined`
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`cluster.storageClass.parameters` | Parameters for StorageClass | `undefined`
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`cluster.persistentVolume.enabled` | If `true`, persistent volume claims are created | `true`
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`cluster.persistentVolume.storageClass` | Persistent volume storage class | `default`
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`cluster.persistentVolume.accessMode` | Persistent volume access modes | `[ReadWriteOnce]`
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`cluster.persistentVolume.size` | Persistent volume size | `1Gi`
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`cluster.persistentVolume.annotations` | Persistent volume annotations | `{}`
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`cluster.rethinkCacheSize` | RethinkDB `cache-size` value in MB | `100`
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`proxy.replicas` | Number of RethinkDB Proxy replicas | `1`
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`proxy.resources` | Resource configuration for each RethinkDB Proxy Pod | `{}`
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`proxy.podAnnotations` | Annotations to be added to RethinkDB Proxy Pods | `{}`
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`proxy.service.type` | RethinkDB Proxy Service Type | `ClusterIP`
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`proxy.service.annotations` | Annotations to be added to RethinkDB Cluster Service | `{}`
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`proxy.service.clusterIP` | Internal controller proxy service IP | `""`
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`proxy.service.externalIPs` | Controller service external IP addresses | `[]`
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`proxy.service.loadBalancerIP` | IP address to assign to load balancer (if supported) | `""`
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`proxy.service.loadBalancerSourceRanges` | List of IP CIDRs allowed access to load balancer (if supported) | `[]`
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`proxy.driverTLS.enabled` | Should RethinkDB Proxy TLS be enabled. **Note**: If enabled, you must set a key and cert | `false`
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`proxy.driverTLS.key` | RSA Private Key | `undefined`
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`proxy.driverTLS.cert` | Certificate | `undefined`
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`ports.cluster` | RethinkDB Cluster Port | `29015`
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`ports.driver` | RethinkDB Driver Port | `28015`
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`ports.admin` | RethinkDB Admin Port | `8080`
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`rethinkdbPassword` | Password for the RethinkDB Admin user | `rethinkdb`
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Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`.
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Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,
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```console
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$ helm install --name my-release -f values.yaml stable/rethinkdb
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```
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> **Tip**: You can use the default [values.yaml](values.yaml)
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## Important: Admin Password Management ##
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The initial admin password is set by the config value `rethinkdbPassword`. This value is also used by the probe which periodically checks if the RethinkDB Cluster and Proxy are still running. If you change the RethinkDB admin password via a query (i.e. `r.db('rethinkdb').table('users').update({password: 'new-password'})`) this will cause the probe to fail which then restarts the pods over and over. To stablize the cluster, you also need to use `helm upgrade` to update the password in the Kubernetes Secrets storage by doing:
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```console
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$ helm upgrade --set rethinkdbPassword=new-password my-release stable/rethinkdb
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```
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## Opening Up the RethinkDB Admin Console
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The admin port is not available outside of the cluster for security reasons. The only way to access the admin console is to use a [Kubernetes Proxy](https://kubernetes.io/docs/concepts/cluster-administration/access-cluster/#manually-constructing-apiserver-proxy-urls). To open up the admin console:
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```console
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$ kubectl proxy
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Starting to serve on 127.0.0.1:8001
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```
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Then use the following URL: http://localhost:8001/api/v1/namespaces/NAMESPACE/services/RELEASE_NAME-rethinkdb-admin/proxy
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Make sure a replace `NAMEPSPACE` with the correct namespace and `RELEASE_NAME` that was used when installing the chart.
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And then open up your browser to http://localhost:8080 and you should see the admin console
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## Cleanup orphaned Persistent Volumes
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Deleting a StatefulSet will not delete associated Persistent Volumes.
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Do the following after deleting the chart release to clean up orphaned Persistent Volumes.
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```console
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$ kubectl delete pvc -l release=my-release
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```
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## Failover
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If any RethinkDB server fails it gets re-joined eventually.
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You can test the scenario by killing process of one of the pods:
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```console
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$ kubectl get pods -l release=my-release
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NAME READY STATUS RESTARTS AGE
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my-release-rethinkdb-cluster-0 1/1 Running 0 1m
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my-release-rethinkdb-cluster-1 1/1 Running 0 2m
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my-release-rethinkdb-cluster-2 1/1 Running 0 2m
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my-release-rethinkdb-proxy-2517940628-81dxd 1/1 Running 1 1m
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$ kubectl exec -it my-release-rethinkdb-cluster-0 -- ps aux | grep 'rethinkdb'
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root 7 0.1 2.1 233496 43408 ? Ssl 16:56 0:00 rethinkdb --ser
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root 26 0.0 0.4 146948 8204 ? S 16:56 0:00 rethinkdb --ser
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root 100 0.0 0.7 157192 16060 ? S 16:56 0:00 rethinkdb --ser
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$ kubectl exec -it my-release-rethinkdb-cluster-0 -- kill 7
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```
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## Scaling
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Scaling should be managed by `helm upgrade`, which is the recommended way. Example:
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```
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$ helm upgrade --set cluster.replicas=4 my-release stable/rethinkdb
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```
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