Apache Pulsar Helm Chart

This project provides Helm Charts for installing Apache Pulsar on Kubernetes.

Read Deploying Pulsar on Kubernetes for more details.

⚠️ This helm chart is updated outside of the regular Pulsar release cycle and might lag behind a bit. It only supports basic Kubernetes features now. Currently, it can be used as no more than a template and starting point for a Kubernetes deployment. In many cases, it would require some customizations.

Features

This Helm Chart includes all the components of Apache Pulsar for a complete experience.

It includes support for:

Requirements

In order to use this chart to deploy Apache Pulsar on Kubernetes, the followings are required.

kubectl 1.21 or higher, compatible with your cluster (+/- 1 minor release from your cluster)
Helm v3 (3.0.2 or higher)
A Kubernetes cluster, version 1.21 or higher.

Environment setup

Before proceeding to deploying Pulsar, you need to prepare your environment.

Tools

helm and kubectl need to be installed on your computer.

Add to local Helm repository

To add this chart to your local Helm repository:

helm repo add apache https://pulsar.apache.org/charts

Kubernetes cluster preparation

You need a Kubernetes cluster whose version is 1.21 or higher in order to use this chart, due to the usage of certain Kubernetes features.

We provide some instructions to guide you through the preparation: http://pulsar.apache.org/docs/helm-prepare/

Deploy Pulsar to Kubernetes

Configure your values file. The best way to know which values are available is to read the values.yaml.

Install the chart:

helm install <release-name> -n <namespace> -f your-values.yaml apache/pulsar

Access the Pulsar cluster

The default values will create a ClusterIP for the proxy you can use to interact with the cluster. To find the IP address of proxy use:
```
kubectl get service -n <k8s-namespace>
```

For more information, please follow our detailed quick start guide.

Customize the deployment

We provide a detailed guideline for you to customize the Helm Chart for a production-ready deployment.

You can also checkout out the example values file for different deployments.

Disabling Kube-Prometheus-Stack CRDs

In order to disable the kube-prometheus-stack fully, it is necessary to add the following to your values.yaml:

kube-prometheus-stack:
  enabled: false
  prometheusOperator:
    enabled: false
  grafana:
    enabled: false
  alertmanager:
    enabled: false
  prometheus:
    enabled: false

Otherwise, the helm chart installation will attempt to install the CRDs for the kube-prometheus-stack. Additionally, you'll need to disable each of the component's PodMonitors. This is shown in some examples and is verified in some tests.

Grafana Dashboards

The Apache Pulsar Helm Chart uses the kube-prometheus-stack Helm Chart to deploy Grafana. Dashboards are loaded via a Kubernetes ConfigMap. Please see their documentation for loading those dashboards.

The apache/pulsar GitHub repo contains some dashboards here.

Third Party Dashboards

StreamNative provides Grafana Dashboards for Apache Pulsar in this GitHub repository.
DataStax provides Grafana Dashboards for Apache Pulsar in this GitHub repository.

Note: if you have third party dashboards that you would like included in this list, please open a pull request.

Upgrading

Once your Pulsar Chart is installed, configuration changes and chart updates should be done using helm upgrade.

helm repo add apache https://pulsar.apache.org/charts
helm repo update
helm get values <pulsar-release-name> > pulsar.yaml
helm upgrade -f pulsar.yaml \
    <pulsar-release-name> apache/pulsar

For more detailed information, see our Upgrading guide.

Upgrading to Apache Pulsar 2.10.0 and above (or Helm Chart version 3.0.0 and above)

The 2.10.0+ Apache Pulsar docker image is a non-root container, by default. That complicates an upgrade to 2.10.0 because the existing files are owned by the root user but are not writable by the root group. In order to leverage this new security feature, the Bookkeeper and Zookeeper StatefulSet securityContexts are configurable in the values.yaml. They default to:

  securityContext:
    fsGroup: 0
    fsGroupChangePolicy: "OnRootMismatch"

This configuration is ideal for regular Kubernetes clusters where the UID is stable across restarts. If the process UID is subject to change (like it is in OpenShift), you'll need to set fsGroupChangePolicy: "Always".

The official docker image assumes that it is run as a member of the root group.

If you upgrade to the latest version of the helm chart before upgrading to Pulsar 2.10.0, then when you perform your first upgrade to version >= 2.10.0, you will need to set fsGroupChangePolicy: "Always" on the first upgrade and then set it back to fsGroupChangePolicy: "OnRootMismatch" on subsequent upgrades. This is because the root file won't mismatch permissions, but the RocksDB lock file will. If you have direct access to the persistent volumes, you can alternatively run chgrp -R g+w /pulsar/data before upgrading.

Here is a sample error you can expect if the RocksDB lock file is not correctly owned by the root group:

2022-05-14T03:45:06,903+0000  ERROR org.apache.bookkeeper.server.Main - Failed to build bookie server
java.io.IOException: Error open RocksDB database
    at org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorageRocksDB.<init>(KeyValueStorageRocksDB.java:199) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorageRocksDB.<init>(KeyValueStorageRocksDB.java:88) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorageRocksDB.lambda$static$0(KeyValueStorageRocksDB.java:62) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.LedgerMetadataIndex.<init>(LedgerMetadataIndex.java:68) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.SingleDirectoryDbLedgerStorage.<init>(SingleDirectoryDbLedgerStorage.java:169) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.DbLedgerStorage.newSingleDirectoryDbLedgerStorage(DbLedgerStorage.java:150) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.storage.ldb.DbLedgerStorage.initialize(DbLedgerStorage.java:129) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.bookie.Bookie.<init>(Bookie.java:818) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.proto.BookieServer.newBookie(BookieServer.java:152) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.proto.BookieServer.<init>(BookieServer.java:120) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.server.service.BookieService.<init>(BookieService.java:52) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.server.Main.buildBookieServer(Main.java:304) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.server.Main.doMain(Main.java:226) [org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    at org.apache.bookkeeper.server.Main.main(Main.java:208) [org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
Caused by: org.rocksdb.RocksDBException: while open a file for lock: /pulsar/data/bookkeeper/ledgers/current/ledgers/LOCK: Permission denied
    at org.rocksdb.RocksDB.open(Native Method) ~[org.rocksdb-rocksdbjni-6.10.2.jar:?]
    at org.rocksdb.RocksDB.open(RocksDB.java:239) ~[org.rocksdb-rocksdbjni-6.10.2.jar:?]
    at org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorageRocksDB.<init>(KeyValueStorageRocksDB.java:196) ~[org.apache.bookkeeper-bookkeeper-server-4.14.4.jar:4.14.4]
    ... 13 more

Recovering from `helm upgrade` error "unable to build kubernetes objects from current release manifest"

Example of the error message:

Error: UPGRADE FAILED: unable to build kubernetes objects from current release manifest:
[resource mapping not found for name: "pulsar-bookie" namespace: "pulsar" from "":
no matches for kind "PodDisruptionBudget" in version "policy/v1beta1" ensure CRDs are installed first,
resource mapping not found for name: "pulsar-broker" namespace: "pulsar" from "":
no matches for kind "PodDisruptionBudget" in version "policy/v1beta1" ensure CRDs are installed first,
resource mapping not found for name: "pulsar-zookeeper" namespace: "pulsar" from "":
no matches for kind "PodDisruptionBudget" in version "policy/v1beta1" ensure CRDs are installed first]

Helm documentation explains issues with managing releases deployed using outdated APIs when the Kubernetes cluster has been upgraded to a version where these APIs are removed. This happens regardless of whether the chart in the upgrade includes supported API versions. In this case, you can use the following workaround:

Install the Helm mapkubeapis plugin:

helm plugin install https://github.com/helm/helm-mapkubeapis

Run the helm mapkubeapis command with the appropriate namespace and release name. In this example, we use the namespace "pulsar" and release name "pulsar":
```
helm mapkubeapis --namespace pulsar pulsar
```

This workaround addresses the issue by updating in-place Helm release metadata that contains deprecated or removed Kubernetes APIs to a new instance with supported Kubernetes APIs and should allow for a successful Helm upgrade.

Uninstall

To uninstall the Pulsar Chart, run the following command:

helm delete <pulsar-release-name>

For the purposes of continuity, these charts have some Kubernetes objects that are not removed when performing helm delete. These items we require you to conciously remove them, as they affect re-deployment should you choose to.

PVCs for stateful data, which you must consciously remove
- ZooKeeper: This is your metadata.
- BookKeeper: This is your data.
- Prometheus: This is your metrics data, which can be safely removed.
Secrets, if generated by our prepare release script. They contain secret keys, tokens, etc. You can use cleanup release script to remove these secrets and tokens as needed.

Troubleshooting

We've done our best to make these charts as seamless as possible, occasionally troubles do surface outside of our control. We've collected tips and tricks for troubleshooting common issues. Please examine these first before raising an issue, and feel free to add to them by raising a Pull Request!

Release Process

See RELEASE.md

hadican/pulsar-helm-chart