pulsar-helm-chart/README.md
Michael Marshall 428736c788
Add bk, zk securityContext to support upgrade to non-root docker image (#266)
Master Issue: https://github.com/apache/pulsar/issues/11269

### Motivation

Apache Pulsar's docker images for 2.10.0 and above are non-root by default. In order to ensure there is a safe upgrade path, we need to expose the `securityContext` for the Bookkeeper and Zookeeper StatefulSets. Here is the relevant k8s documentation on this k8s feature: https://kubernetes.io/docs/tasks/configure-pod-container/security-context.

Once released, all deployments using the default `values.yaml` configuration for the `securityContext` will pay a one time penalty on upgrade where the kubelet will recursively chown files to be root group writable. It's possible to temporarily avoid this penalty by setting `securityContext: {}`.

### Modifications

* Add config blocks for the `bookkeeper.securityContext` and `zookeeper.securityContext`.
* Default to `fsGroup: 0`. This is already the default group id in the docker image, and the docker image assumes the user has root group permission.
* Default to `fsGroupChangePolicy: "OnRootMismatch"`. This configuration will work for all deployments where the user id is stable. If the user id switches between restarts, like it does in OpenShift, please set to `Always`.
* Remove gc configuration writing to directory that the user lacks permission. (Perhaps we want to write to `/pulsar/log/bookie-gc.log`?) 
* Add documentation to the README.

### Verifying this change

I first attempted verification of this change with minikube. It did not work because minikube uses hostPath volumes by default. I then tested on EKS v1.21.9-eks-0d102a7. I tested by deploying the current, latest version of the helm chart (2.9.3) and then upgrading to this PR's version of the helm chart along with using the 2.10.0 docker image. I also tested upgrading from a default version 

Test 1 is a plain upgrade using the default 2.9.3 version of the chart, then upgrading to this PR's version of the chart with the modification to use the 2.10.0 docker images. It worked as expected.

```bash
$ helm install test apache/pulsar
$ # Wait for chart to deploy, then run the following, which uses Pulsar version 2.10.0:
$  helm upgrade test -f charts/pulsar/values.yaml charts/pulsar/
```

Test 2 is a plain upgrade using the default 2.9.3 version of the chart, then an upgrade to this PR's version of the chart, then an upgrade to this PR's version of the chart using 2.10.0 docker images. There is a minor error described in the `README.md`. The solution is to chown the bookie's data directory.

```bash
$ helm install test apache/pulsar
$ # Wait for chart to deploy, then run the following, which uses Pulsar version 2.9.2:
$  helm upgrade test -f charts/pulsar/values.yaml charts/pulsar/
$ # Upgrade using Pulsar version 2.10.0
$  helm upgrade test -f charts/pulsar/values.yaml charts/pulsar/
```

### GC Logging

In my testing, I ran into the following errors when using `-Xlog:gc:/var/log/bookie-gc.log`:

```
pulsar-bookkeeper-verify-clusterid [0.008s] Error opening log file '/var/log/bookie-gc.log': Permission denied
pulsar-bookkeeper-verify-clusterid [0.008s] Initialization of output 'file=/var/log/bookie-gc.log' using options '(null)' failed.
pulsar-bookkeeper-verify-clusterid [0.005s] Error opening log file '/var/log/bookie-gc.log': Permission denied
pulsar-bookkeeper-verify-clusterid [0.006s] Initialization of output 'file=/var/log/bookie-gc.log' using options '(null)' failed.
pulsar-bookkeeper-verify-clusterid Invalid -Xlog option '-Xlog:gc:/var/log/bookie-gc.log', see error log for details.
pulsar-bookkeeper-verify-clusterid Error: Could not create the Java Virtual Machine.
pulsar-bookkeeper-verify-clusterid Error: A fatal exception has occurred. Program will exit.
pulsar-bookkeeper-verify-clusterid Invalid -Xlog option '-Xlog:gc:/var/log/bookie-gc.log', see error log for details.
pulsar-bookkeeper-verify-clusterid Error: Could not create the Java Virtual Machine.
pulsar-bookkeeper-verify-clusterid Error: A fatal exception has occurred. Program will exit.
```

I resolved the error by removing the setting.

### OpenShift Observations

I wanted to seamlessly support OpenShift, so I investigated using configuring the bookkeeper and zookeeper process with `umask 002` so that they would create files and directories that are group writable (OpenShift has a stable group id, but gives the process a random user id). That worked for most tools when switching the user id, but not for RocksDB, which creates a lock file at `/pulsar/data/bookkeeper/ledgers/current/ledgers/LOCK` with the permission `0644` ignoring the umask. Here is the relevant error:

```
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
```

As such, in order to support OpenShift, I exposed the `fsGroupChangePolicy`, which allows for OpenShift support, but not necessarily _seamless_ support.
2022-06-13 22:11:13 -05:00

12 KiB

Official Apache Pulsar Helm Chart

This is the officially supported Helm Chart for installing Apache Pulsar on Kubernetes.

Read Deploying Pulsar on Kubernetes for more details.

Features

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

  • Pulsar core components:
    • ZooKeeper
    • Bookies
    • Brokers
    • Functions
    • Proxies
  • Management & monitoring components:
    • Pulsar Manager
    • Prometheus
    • Grafana

It includes support for:

  • Security
    • Automatically provisioned TLS certs, using Jetstack's cert-manager
    • TLS Encryption
      • Proxy
      • Broker
      • Toolset
      • Bookie
      • ZooKeeper
    • Authentication
      • JWT
      • Mutal TLS
      • Kerberos
    • Authorization
    • Non-root broker, bookkeeper, proxy, and zookeeper containers (version 2.10.0 and above)
  • Storage
    • Non-persistence storage
    • Persistence Volume
    • Local Persistent Volumes
    • Tiered Storage
  • Functions
    • Kubernetes Runtime
    • Process Runtime
    • Thread Runtime
  • Operations
    • Independent Image Versions for all components, enabling controlled upgrades

Requirements

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

  1. kubectl 1.18 or higher, compatible with your cluster (+/- 1 minor release from your cluster)
  2. Helm v3 (3.0.2 or higher)
  3. A Kubernetes cluster, version 1.18 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

To use the helm chart:

helm install <release-name> apache/pulsar

Kubernetes cluster preparation

You need a Kubernetes cluster whose version is 1.18 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/en/helm-prepare/

Deploy Pulsar to Kubernetes

  1. Clone the Pulsar Helm charts repository.

    git clone https://github.com/apache/pulsar-helm-chart
    
    cd pulsar-helm-chart
    
  2. Run prepare_helm_release.sh to create required kubernetes resources for installing this Helm chart.

    • A k8s namespace for installing the Pulsar release (if -c is specified)
    • Create the JWT secret keys and tokens for three superusers: broker-admin, proxy-admin, and admin. By default, it generates asymmetric pubic/private key pair. You can choose to generate symmetric secret key by specifying --symmetric in the following command.
      • proxy-admin role is used for proxies to communicate to brokers.
      • broker-admin role is used for inter-broker communications.
      • admin role is used by the admin tools.
    ./scripts/pulsar/prepare_helm_release.sh -n <k8s-namespace> -k <pulsar-release-name> -c
    
  3. Use the Pulsar Helm charts to install Apache Pulsar.

    This command installs and starts Apache Pulsar.

    $ helm install <pulsar-release-name> apache/pulsar
    
  4. 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.

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 2.10.0 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

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

  1. Bump the version in charts/pulsar/Chart.yaml.

  2. Send a pull request for reviews.

  3. After the pull request is approved, merge it. The release workflow will be triggered automatically.

    • It creates a tag named pulsar-<version>.
    • Published the packaged helm chart to Github releases.
    • Update the charts/index.yaml in Pulsar website.
  4. Trigger the Pulsar website build to make the release available under https://pulsar.apache.org/charts.