https://github.com/unicef/magasin-drill
Apache Drill and Apache Zookeeper helm charts for kubernetes
https://github.com/unicef/magasin-drill
apache-drill apache-zookeeper charts drill drill-clusters helm helm-chart kubernetes magasin zookeeper
Last synced: about 1 year ago
JSON representation
Apache Drill and Apache Zookeeper helm charts for kubernetes
- Host: GitHub
- URL: https://github.com/unicef/magasin-drill
- Owner: unicef
- License: apache-2.0
- Created: 2023-11-06T10:42:00.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2024-12-02T13:23:20.000Z (over 1 year ago)
- Last Synced: 2025-04-01T14:21:37.497Z (about 1 year ago)
- Topics: apache-drill, apache-zookeeper, charts, drill, drill-clusters, helm, helm-chart, kubernetes, magasin, zookeeper
- Language: Shell
- Homepage:
- Size: 1.12 MB
- Stars: 2
- Watchers: 8
- Forks: 2
- Open Issues: 7
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Security: SECURITY.md
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README
# Helm Charts for Apache Drill
[](https://artifacthub.io/packages/search?repo=magasin-drill)
This repository contains a collection of files that can be used to deploy [Apache Drill](http://drill.apache.org/) on [Kubernetes](https://kubernetes.io/) using [Helm Charts](https://helm.sh/). Supports single-node and [cluster](http://drill.apache.org/docs/installing-drill-in-distributed-mode/) modes.
This is an extended version of the originally chart created in [github.com/Agirish/drill-helm-charts](https://github.com/Agirish/drill-helm-charts).
This extension has been created to fit the needs of [UNICEF's magasin](https://github.com/unicef/magasin), an end-to-end data AI/ML cloud data platform based.
**Chart Versions**
| Chart Version | Drill Version | Zookeeper Version | Release Date | Release notes |
|---------------|---------------|-------------------|--------------------|------------------------|
| 0.9.0 | 1.21.2 | 3.9.3 | 2024-12-02 | [Release notes v0.9.0](https://github.com/unicef/magasin-drill/releases/tag/releases%2Fv0.9.0) |
| 0.8.0 | 1.21.2 | 3.9.2 | 2024-09-04 | [Release notes v0.8.0](https://github.com/unicef/magasin-drill/releases/tag/releases%2Fv0.8.0) |
| 0.7.2 | 1.21.2 | 3.9.2 | 2024-08-07 | [Release notes v0.7.2](https://github.com/unicef/magasin-drill/releases/tag/releases%2Fv0.7.2) |
| 0.7.1 | 1.21.1 | 3.9.1 | 2024-02-05 | [Release notes v0.7.1](https://github.com/unicef/magasin-drill/releases/tag/releases%2Fv0.7.1) |
---
## Pre-requisites
- A Kubernetes Cluster.
- [Helm](https://github.com/helm/helm#install) version 3.0 or greater.
- [Kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) version 1.16.0 or greater.
## Install
### Option 1: Using the Helm repository (recommended)
1. Add the helm repo
```sh
helm repo add magasin-drill https://unicef.github.io/magasin-drill/
```
2. Intall the chart
```sh
helm install drill magasin-drill/drill --namespace magasin-drill --create-namespace
```
This will install Apache Drill in the `magasin-drill` namespace. If you skip `--namespace magasin-drill --create-namespace` the chart is installed in the `default` namespace.
### Option 2: Cloning the repo
1. Clone the repo
```sh
git clone https://github.com/unicef/magasin-drill
```
2. Install the chart
```sh
cd magasin-drill
helm install drill ./charts/drill --namespace magasin-drill --create-namespace
```
This will install Apache Drill in the `magasin-drill` namespace. If you skip `--namespace magasin-drill --create-namespace` the chart is installed in the `default` namespace.
## Usage
You can list the pods by running:
```shell
# kubectl get pods -n
kubectl get pods -n magasin-drill
NAME READY STATUS RESTARTS AGE
drillbit-0 1/1 Running 0 5m3s
drillbit-1 1/1 Running 0 5m3s
zk-0 1/1 Running 0 5m3s
```
Once all the pods have the READY value as `1/1` and the `STATUS` is `Running`, you can launch the Drill Web UI using:
```sh
kubectl port-forward --namespace magasin-drill service/drill-service 8047:8047
```
Then open the browser in `http://localhost:8047` to access the Drill Web UI.
Or you can download the [launch_ui.sh script from this repo](https://github.com/unicef/magasin-drill/blob/main/scripts/launch_ui.sh) and run it:
```shell
# ./scripts/launch_ui [-n ]
# where namespace defaults to "magasin-drill"
./scripts/launch_ui.sh
```
It will output
```
Forwarding from 127.0.0.1:8047 -> 8047
Forwarding from [::1]:8047 -> 8047
```
Then open `http://localhost:8047` in a browser.
The chart `appVersion` displays the drill and zookeeper versions, respectively.
For example:
```shell
helm list -n magasin-drill
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
drill magasin-drill 1 2023-11-20 09:12:48.88172 +0300 EAT deployed drill-0.7.2 1.21.2-3.9.2
```
### Install cloning repo
Alternatively, you can clone this repo and install the chart from the local directory:
```sh
git clone https://github.com/unicef/magasin-drill
cd magasin-drill
helm install drill ./charts/drill --namespace magasin-drill --create-namespace
```
### Customizing the setup
Helm Charts use `values.yaml` for providing default values to 'variables' used in the chart templates. Refer to the [charts/drill/values.yaml](charts/drillvalues.yaml) file for details on default values for the charts.
You can create a `values.yaml`` file to overrides some of the default values. For example, by default the helm chart launches 2 drillbits, but you can set it to 1.
```yaml
# values.yaml
drill:
count: 1
```
Then you add the `-f filename.yaml` or `--values filename.yaml` to the install command earlier
```sh
helm install drill magasin-drill/drill -f values.yaml -n magasin-drill --create-namespace
```
If the setup already exist you can use `upgrade`:
```sh
helm upgrade drill magasin-drill/drill -n magasin-drill -f values.yaml
Release "drill" has been upgraded. Happy Helming!
NAME: drill
LAST DEPLOYED: Wed Nov 8 13:41:10 2023
NAMESPACE: magasin-drill
STATUS: deployed
REVISION: 2
TEST SUITE: None
```
Now, the cluster only has a drillbit:
```shell
kubectl get pods -n magasin-drill
NAME READY STATUS RESTARTS AGE
drillbit-0 0/1 Running 1 (22s ago) 156m
zk-0 1/1 Running 0 157m
```
### Override the storage plugin configuration
It is possible to deploy drill with a custom set of storage plugins (ie. connected to a set of storages such as Azure Blobs, S3 Buckets, etc.).
To do that:
1. Edit the configuration file: `storage-plugins-override.conf`.
2. Enable the storage plugin config overriding by setting to `true` the `drill.volumes.drillStorage.override` section in your values file `values.yaml` file.
```yaml
# values.yaml
drill:
volumes:
drillStorage:
override: true
```
3. Create the `drill-storage-plugin-secret` secret. When a Drill chart is deployed, the files contained within this secret will be downloaded to each container and used by the drill-bit process during start-up. You can create the secret by running the script:
```shell
# ./scripts/create_secret.sh
./scripts/create_secret.sh -n magasin-drill -f
```
or manually
```shell
kubectl create secret generic drill-storage-plugin-secret --from-file=storage-plugins-override.conf --namespace magasin-drill
```
#### Override drill config
You can enable config overriding by modifying the values of the `drill.volumes.configOverrides` in your customized `values.yaml` file. Example:
```yaml
# values.yaml
drill:
volumes:
# Make true if you want to add any volumes. Else, make false.
add: true
# Drill Configuration can be overridden by mounting them on each Drill container.
configOverrides:
# Contents of drill-override.conf
# This file follows the HOCON format
# https://github.com/lightbend/config/blob/master/HOCON.md
# The available options are described:
# # https://drill.apache.org/docs/configuration-options-introduction/
#
# Alternatively on the web UI you can run the query:
#
# SELECT * FROM sys.boot;
#
drillOverrideConf: |
drill.exec.options.exec.errors.verbose: true
# Contents of drill-env.sh
drillEnvSh: |
echo "Running drill-env.sh..."
export DRILL_PID_DIR="/opt/drill"
ps -ax
env
#...
```
#### Allow access to Drill web UI from outside of the cluster.
By default, you can only access the Drill Web UI by performing a port forward to your localhost `using scripts/launch_ui.sh` or using `kubectl`:
`kubectl port-forward --namespace service/drill-service 8047:8047`
For cloud based deployments, you can setup a `LoadBalancer` type [service](https://kubernetes.io/docs/concepts/services-networking/service/). This allows to access the drill web UI from outside the cluster through a public IP. Basically, this type of service acts like a proxy which internally redirects the HTTP requests to any of the available drill pods.
To enable the service, modify the flag `exposeWebService` in your `values.yaml` in the `drill` section.
```yaml
# values.yaml
drill:
#...
#...
exposeWebService: true
webServiceType: LoadBalancer
#...
#...
```
and proceed to upgrade the setup.
Alternatively, you can upgrade your setup just changing the value
```shell
helm upgrade drill magasin-drill/drill -n magasin-drill --set drill.exposeWebService=true
```
Now the drill-web-svc shall appear.
```shell
kubectl get services -n magasin-drill
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
drill-service ClusterIP 10.96.253.218 8047/TCP,31010/TCP,31011/TCP,31012/TCP 28s
drill-web-svc LoadBalancer 10.96.20.170 23.16.193.208 8047:31889/TCP,31010:31926/TCP 28s
zk-service ClusterIP 10.96.54.14 2181/TCP,2888/TCP,3888/TCP 2
```
You can open http://[external-ip]:8047 to access the cluster.
Exposing the cluster externally is **not recommended without enabling the authentication**. Anyone will be able to access your drill!!!
You can read more on [drill documentation about how to enable authentication](https://drill.apache.org/docs/securing-drill-introduction/)
### Deploy multiple drill clusters
Kubernetes [Namespaces](https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/) can be used when more that one Drill Cluster needs to be created. The `default` namespace is used by default.
```shell
# helm install repo/chart --namespace --create-namespace
helm install drill2 magasin-drill/drill --namespace magasin-drill2 --create-namespace
```
Note that installing the Drill Helm Chart also installs the dependent Zookeeper chart. So with current design, for each instance of a Drill cluster includes a single-node Zookeeper.
```shell
kubectl get pods -n magasin-drill2
NAME READY STATUS RESTARTS AGE
drill2bit-0 1/1 Running 0 51s
drill2bit-1 1/1 Running 0 51s
zk-0 1/1 Running 0 51s
```
You can use the `launch_ui.sh` script with the `-n ` as argument
```shell
./scripts/launch_ui.sh -n magasin-drill2
```
### Upgrading Drill Charts
Currently only scaling up/down the number of Drill pods is supported as part of Helm Chart upgrades. To resize a Drill Cluster, edit the `values.yaml` file and apply the changes as below:
```shell
#
helm upgrade drill1 magasin-drill/drill -f values.yaml
# If cloned this repo
# helm upgrade repo/chart/
helm upgrade drill1 magasin-drill/drill
```
Alternatively, provide the count as a part of the `upgrade` command:
```shell
# helm upgrade repo/chart --set drill.count=2
helm upgrade drill1 magasin-drill/drill --set drill.count=2
```
### Autoscaling Drill Clusters
The size of the Drill cluster (number of Drill Pod replicas / number of drill-bits) can not only be manually scaled up or down as shown above, but can also be autoscaled to simplify cluster management. When enabled, with a higher CPU utilization, more drill-bits are added automatically and as the cluster load goes down, so do the number of drill-bits in the Drill Cluster. The drill-bits deemed excessive [gracefully shut down](https://drill.apache.org/docs/stopping-drill/#gracefully-shutting-down-the-drill-process), by going into quiescent mode to permit running queries to complete.
Enable autoscaling by editing the drill.autoscale section in `charts/drill/values.yaml` file.
```yaml
# values.yaml
drill:
#...
#..
autoscale:
# Flag to turn-on / turn-off this option
enabled: true
# Maximum number of Drill Pods
maxCount: 4
# Target CPU Utilization Percentage
cpuThreshold: 75
```
If autoscaling is enabled:
```shell
# helm upgrade repo/chart --set drill.count= --set drill.autoscale.maxCount=
helm upgrade drill1 magasin-drill/drill --set drill.count=3 --set drill.autoscale.maxCount=6
```
### Package
Drill Helm Charts can be packaged for distribution as follows:
```sh
helm package charts/drill/
Successfully packaged chart and saved it to: /xxx/magasin-drill/drill-1.0.0.tgz
```
### Uninstall
Drill Helm Charts can be uninstalled as follows:
```shell
# helm [uninstall|delete] -n
helm delete drill1
helm delete drill2
```
Note that `LoadBalancer` and a few other Kubernetes resources may take a while to terminate. Before re-installing Drill Helm Charts, please make sure to wait until all objects from any previous installation (in the same namespace) have terminated.
## Building custom docker images
The [`docker/`](docker/) directory contains everything required to build and customize the Docker images of Apache Drill and Apache ZooKeeper included in the helm chart.
Already built docker images are available in [Docker Hub](https://hub.docker.com/u/merlos/).
Once you have updated the images, you need to replace the 'image' option in your `values.yaml` file.
To update the drill image edit the `drill.image` value:
```yaml
drill:
#...
# Change the line below with your custom image
image: merlos/drill:1.21.1-multi-arch
```
And, in the zookeeper section:
```yaml
zookeper:
#...
#...
# Change the line below with your custom image
image: merlos/zookeeper:3.9.1-multi-arch
```
## Troubleshooting
Assuming we have installed the helm chart in the `magasin-drill` namespace we'll explore how to fix an issue
Check the health of the pods:
```shell
kubectl get pods -n magasin-drill
NAME READY STATUS RESTARTS AGE
drillbit-0 0/1 Running 0 4m25s
drillbit-1 0/1 Running 0 4m25s
zk-0 1/1 Running 0 4m5s
```
If after a few min the status is not Running as well as the readiness is "1/1", then you may be spotting a problem.
In that case, it is good to expand on the status of the pod. To do that you can use the describe pod kubectl command.
Generally you'll need to take a deeper look to the Events section:
```shell
# kubectl describe pod -n
kubectl describe pod drillbit-0 -n magasin-drill
Name: drillbit-0
Namespace: magasin-drill
Priority: 0
Service Account: drill-sa
...
...
...
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 2m default-scheduler Successfully assigned magasin-drill/drillbit-0 to aks-systempool-32354579-vmss00000o
Normal Pulling 2m kubelet Pulling image "busybox"
Normal Pulled 119s kubelet Successfully pulled image "busybox" in 756.658172ms (756.671572ms including waiting)
Normal Created 119s kubelet Created container zk-available
Normal Started 119s kubelet Started container zk-available
Normal Pulling 118s kubelet Pulling image "merlos/drill:1.21.1"
Normal Pulled 117s kubelet Successfully pulled image "merlos/drill:1.21.1" in 730.646907ms (730.656407ms including waiting)
Normal Created 117s kubelet Created container drill-pod
Normal Started 117s kubelet Started container drill-pod
Warning Unhealthy 30s (x3 over 90s) kubelet Liveness probe failed: Running drill-env.sh...
/opt/drill/drillbit.pid file is present but drillbit is not running.
[WARN] Only DRILLBIT_MAX_PROC_MEM is defined. Auto-configuring for Heap & Direct memory
[INFO] Attempting to start up Drill with the following settings
DRILL_HEAP=1G
DRILL_MAX_DIRECT_MEMORY=3G
DRILLBIT_CODE_CACHE_SIZE=768m
Warning Unhealthy 25s (x4 over 90s) kubelet Readiness probe failed: Running drill-env.sh...
/opt/drill/drillbit.pid file is present but drillbit is not running.
[WARN] Only DRILLBIT_MAX_PROC_MEM is defined. Auto-configuring for Heap & Direct memory
[INFO] Attempting to start up Drill with the following settings
DRILL_HEAP=1G
DRILL_MAX_DIRECT_MEMORY=3G
DRILLBIT_CODE_CACHE_SIZE=768m
```
In this case, among the info, we see the line bellow, that tells us that the drillbit is not running.
```
/opt/drill/drillbit.pid file is present but drillbit is not running.
```
But this is not enough info. Another thing we can try is to display the logs:
```shell
# kubectl logs -n -f
kubectl logs drillbit-0 -n magasin-drill -f
Defaulted container "drill-pod" out of: drill-pod, zk-available (init)
sed: cannot rename /opt/drill/conf/sedQRvtNI: Device or resource busy
sed: cannot rename /opt/drill/conf/sed6kHmUI: Device or resource busy
Running drill-env.sh...
[WARN] Only DRILLBIT_MAX_PROC_MEM is defined. Auto-configuring for Heap & Direct memory
[INFO] Attempting to start up Drill with the following settings
DRILL_HEAP=1G
DRILL_MAX_DIRECT_MEMORY=3G
DRILLBIT_CODE_CACHE_SIZE=768m
Starting drillbit, logging to /var/log/drill/drillbit.out
Running drill-env.sh...
[WARN] Only DRILLBIT_MAX_PROC_MEM is defined. Auto-configuring for Heap & Direct memory
[INFO] Attempting to start up Drill with the following settings
DRILL_HEAP=1G
DRILL_MAX_DIRECT_MEMORY=3G
DRILLBIT_CODE_CACHE_SIZE=768m
drillbit is running.
```
The `-f` argument will display new logs continuously. In this case, these logs do not give us any additional clue. So, next step is to look inside of the pod itself:
```sh
# kubectl exec -n -ti --
kubectl exec drillbit-0 -n magasin-drill -ti -- /bin/bash
```
This command will launch a shell within the pod. `-ti` is to allow interactive mode.
Within the shell we can explore the `/opt/drill/conf` and `/var/log/drill/` folders.
```sh
[root@drillbit-0 /]# pwd
/
[root@drillbit-0 /]# cd /opt/drill/conf/
[root@drillbit-0 conf]# ls
core-site-example.xml drill-metastore-override-example.conf logback.xml
distrib-env.sh drill-on-yarn-example.conf saffron.properties
distrib-setup.sh drill-override-example.conf storage-plugins-override-example.conf
drill-am-log.xml drill-override.conf yarn-client-log.xml
drill-distrib.conf drill-setup.sh
drill-env.sh drill-sqlline-override-example.conf
[root@drillbit-0 conf]#
```
The `drill-env.sh` is the custom script that is run prior to launching the pod. You can check that the contents are the ones you set in `values.yaml`.
The `drill-override.conf` is the custom configuration you set in `values.yaml`.
In the logs folder we have two files:
```
root@drillbit-0 conf]# cd /var/log/drill/
[root@drillbit-0 log]# ls
drillbit.log drillbit.out drillbit_queries.json
[root@drillbit-0 log]#
```
We can explore `drillbit.log` and `drillbit.out`
```shell
[root@drillbit-0 log]# cat drillbit.out
OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N
Exception in thread "main" com.typesafe.config.ConfigException$Parse: drill-override.conf @ file:/opt/drill/conf/drill-override.conf: 5: unbalanced close brace '}' with no open brace (if you intended '}' to be part of a key or string value, try enclosing the key or value in double quotes)
at com.typesafe.config.impl.ConfigDocumentParser$ParseContext.parseError(ConfigDocumentParser.java:201)
at com.typesafe.config.impl.ConfigDocumentParser$ParseContext.parseError(ConfigDocumentParser.java:197)
at com.typesafe.config.impl.ConfigDocumentParser$ParseContext.parseObject(ConfigDocumentParser.java:434)
at com.typesafe.config.impl.ConfigDocumentParser$ParseContext.parse(ConfigDocumentParser.java:648)
at com.typesafe.config.impl.ConfigDocumentParser.parse(ConfigDocumentParser.java:14)
at com.typesafe.config.impl.Parseable.rawParseValue(Parseable.java:262)
at com.typesafe.config.impl.Parseable.rawParseValue(Parseable.java:250)
at com.typesafe.config.impl.Parseable.parseValue(Parseable.java:180)
at com.typesafe.config.impl.Parseable.parseValue(Parseable.java:174)
at com.typesafe.config.impl.Parseable.parseValue(Parseable.java:309)
at com.typesafe.config.impl.Parseable$ParseableResources.rawParseValue(Parseable.java:738)
at com.typesafe.config.impl.Parseable$ParseableResources.rawParseValue(Parseable.java:701)
at com.typesafe.config.impl.Parseable.parseValue(Parseable.java:180)
at com.typesafe.config.impl.Parseable.parseValue(Parseable.java:174)
at com.typesafe.config.impl.Parseable.parse(Parseable.java:152)
at com.typesafe.config.impl.SimpleIncluder.fromBasename(SimpleIncluder.java:172)
at com.typesafe.config.impl.ConfigImpl.parseResourcesAnySyntax(ConfigImpl.java:133)
at com.typesafe.config.ConfigFactory.parseResourcesAnySyntax(ConfigFactory.java:1083)
at com.typesafe.config.ConfigFactory.load(ConfigFactory.java:118)
at com.typesafe.config.ConfigFactory.load(ConfigFactory.java:79)
at org.apache.drill.common.config.DrillConfig.create(DrillConfig.java:270)
at org.apache.drill.common.config.DrillConfig.create(DrillConfig.java:165)
at org.apache.drill.common.config.DrillConfig.create(DrillConfig.java:149)
at org.apache.drill.exec.server.Drillbit.start(Drillbit.java:556)
at org.apache.drill.exec.server.Drillbit.main(Drillbit.java:552)
[root@drillbit-0 log]# command terminated with exit code 137
```
There is one line:
```
Exception in thread "main" com.typesafe.config.ConfigException$Parse: drill-override.conf @ file:/opt/drill/conf/drill-override.conf: 5: unbalanced close brace '}' with no open brace (if you intended '}' to be part of a key or string value, try enclosing the key or value in double quotes)
```
In this case the line tells us that there is a `}` in excess. Let's check it in the file:
```sh
[root@drillbit-0 /]# cat /opt/drill/conf/drill-override.conf
exec.errors: {
verbose: true
}
}
[root@drillbit-0 /]#
```
Effectively that is the case.
Now, we just need to update the `values.yaml` file and install again the chart.
### Error: ImagePullBackOff in minikube
For testing purposes you may be running your cluster in [minikube](https://minikube.sigs.k8s.io/). We have experimented `Error: ImagePullBackOff` errors.
For example after running
```shell
kubectl describe pods zk-0 -n magasin-drill
```
You may see something like:
```
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 2m40s default-scheduler Successfully assigned magasin-drill/zk-0 to minikube
Warning Failed 37s kubelet Failed to pull image "merlos/zookeeper:3.9.1": rpc error: code = Unknown desc = context deadline exceeded
Warning Failed 37s kubelet Error: ErrImagePull
Normal BackOff 37s kubelet Back-off pulling image "merlos/zookeeper:3.9.1"
Warning Failed 37s kubelet Error: ImagePullBackOff
Normal Pulling 22s (x2 over 2m40s) kubelet Pulling image "merlos/zookeeper:3.9.1"
```
In this case, you can fix the issue by pulling the image manually using the following command:
```shell
# minikube image pull
minikube image pull merlos/zookeeper:3.9.1
minikube image pull merlos/drill:1.21.1
```
These will download the images locally so they'll be available. Use `minikube image ls` to view the images available and `minikube image remove ` to remove them.
## The chart structure
Apache Drill Helm charts are organized as a collection of files inside of the `charts/drill/` directory. As Drill depends on [Apache Zookeeper](https://zookeeper.apache.org/) for cluster co-ordination, a zookeeper chart is inside the dependencies folder ['charts/drill/charts'](charts/drill/charts/). The Zookeeper chart follows a similar structure as the Drill chart.
```
charts/drill/
Chart.yaml # A YAML file with information about the chart
values.yaml # The default configuration values for this chart
charts/ # A directory containing the Zookeeper (zk) charts
templates/ # A directory of templates, when combined with values, will generate valid Kubernetes manifest files
```
#### Templates
Helm Charts contain `templates` which are used to generate Kubernetes manifest files. These are YAML-formatted resource descriptions that Kubernetes can understand. These templates contain 'variables', values for which are picked up from the `values.yaml` file.
Drill Helm Charts contain the following templates:
```
charts/drill/
...
templates/
drill-rbac-*.yaml # To enable RBAC for the Drill app
drill-service.yaml # To create a Drill Service
drill-web-service.yaml # To expose Drill's Web UI externally using a LoadBalancer. Works on cloud deployments only.
drill-statefulset.yaml # To create a Drill cluster
charts/
zookeeper/
...
templates/
zk-rbac.yaml # To enable RBAC for the ZK app
zk-service.yaml # To create a ZK Service
zk-statefulset.yaml # To create a ZK cluster. Currently only a single-node ZK (1 replica) is supported
```
## Contributing
We welcome contributions. To contribute, please fork this repository, make your changes, and submit a pull request.
If new values are added to the `values.yaml` file include the documentation on how to use them.
If you find a bug or have a feature request, please open an issue.
## License
Apache License 2.0 UNICEF.org
Note tha this is an updated version of the original: https://github.com/Agirish/drill-helm-charts