[jira] [Commented] (DRILL-7563) Docker & Kubernetes Drill server container

["Abhishek Girish (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-7563?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17063608#comment-17063608 ] 

Abhishek Girish commented on DRILL-7563:
----------------------------------------

Hey [~Paul.Rogers], [~arina], and all, sorry I missed this JIRA + comments in it.

I would like to share this GitHub repository of mine: https://github.com/Agirish/drill-helm-charts . Kindly take a look when you have some time.

It has support for deploying Apache Drill clusters on Kubernetes using the Helm Charts approach. It's functional out-of-box (I've deployed on a standard GKE Kubernetes Cluster) and I'm frequently adding fixes, improvements and new features. There are a few things missing - such as support for passing Drill configuration files as ConfigMaps, which I'm working on (but it has the most common configs available for anyone to change differently). 
The documentation has all the basic details on repo structure & usage, and I'm working on adding more information to it. This requires custom Dockerfiles and I have included those in the repo as well. 

I also have an alternate implementation by building a new native Kubernetes Operator for Apache Drill which can provide more flexibility and power. But for now, I'd like to focus on getting the above Helm Charts approach to be fully feature complete, reviewed and committed, so that we could ship them in an upcoming release.

Please feel free to submit corrections / enhancements as PRs (or file GitHub issues with comments) to the repo above until this is part of the official Drill repo: https://github.com/Agirish/drill-helm-charts/issues

> Docker & Kubernetes Drill server container
> ------------------------------------------
>
>                 Key: DRILL-7563
>                 URL: https://issues.apache.org/jira/browse/DRILL-7563
>             Project: Apache Drill
>          Issue Type: Improvement
>    Affects Versions: 1.17.0
>            Reporter: Paul Rogers
>            Assignee: Paul Rogers
>            Priority: Major
>
> Drill provides two Docker containers:
> * [Build Drill from sources|https://github.com/apache/drill/blob/master/Dockerfile]
> * [Run Drill in interactive embedded mode|https://github.com/apache/drill/blob/master/distribution/Dockerfile]
> User feedback suggests that these are not quite the right solutions to run Drill in a K8s (or OpenShift) cluster. In addition, we need a container to run a Drill server. This ticket summarizes the tasks involved.
> h4. Container Image
> The container image should:
> * Start with the OpenJDK base image with minimal extra packages.
> * Download and install an official Drill release.
> We may then want to provide two derived images:
> The Drillbit image which:
> * Configures Drill for production and as needed in the following steps.
> * Provides entry points for the Drillbit and for Sqlline
> * Exposes Drill's four ports
> * Accept as parameters things like the ZK host IP(s).
> The Sqlline image, meant to be run in interactive mode (like the current embedded image) and which:
> * Accept as parameters the ZK host IP(s).
> Both should be published to the official Drill DockerHub account: https://hub.docker.com/r/apache/drill
> h4. Runtime Environment
> Drill has very few dependencies, but it must have a running ZK.
> * Start a [ZK container|https://hub.docker.com/_/zookeeper/].
> * A place to store logs, which can be in the container by default, stored on the host file system via a volume mount.
> * Access to a data source, which can be configured via a storage plugin stored in ZK.
> * Ensure graceful shutdown integration with the Docker shutdown mechanism.
> h4. Running Drill in Docker
> Users must run at least one Drillbit, and may run more. Users may want to run Sqlline.
> * The Drillbit container requires, at a minimum, the IP address of the ZK instance(s).
> * The Sqlline container requires only the ZK instances, from which it can find the Drillbit.
> Uses will want to customize some parts of Drill: at least memory, perhaps any of the other options. Provide a way to pass this information into the container to avoid the need to rebuild the container to change configuration.
> h4. Running Drill in K8s
> The containers should be usable in "plain" Docker. Today, however, many people use K8s to orchestrate Docker. Thus, the Drillbit (but probably not the Sqlline) container should be designed to work with K8s. An example set of K8s YAML files should illustrate:
> * Create a host-mount file system to capture Drill logs and query profiles.
> * Optionally write Drill logs to stdout, to be captured by {{fluentd}} or similar tools.
> * Pass Drill configuration (both HOCON and envrironment) as config maps.
> * Pass ZK as an environment variable (the value of which would, one presumes, come from some kind of service discovery system.)
> The result is that the user should be able to manually tinker with the YAML files, then use {{kubeadm}} to launch, monitor and stop Drill. The user sets cluster size manually by launching the desired number of Drill pods.
> h4. Helm Chart for Drill
> The next step is to wrap the YAML files in a Helm chart, with parameters exposed for the config options noted above.
> h4. Drill Operator for K8s
>  
> Full K8s integration will require an operator to manage the Drill cluster. K8s operators are often written in Go, though doing so is not necessary. Drill already includes Drill-on-YARN which is, essential a "YARN operator." Repurpose this code to work with K8s as the target cluster manager rather than YARN. Reuse the same operations from DoY: configure, start, resize and stop a cluster.
> h4. Security
> The above steps provide an "MVP": minimum viable project - it will run Drill with standard options in the various environments. Users who chose to run Drill in production will likely require additional security settings. Enable SSL? Control ingress? We need to understand what is needed, what Drill offers, and how to enable Drill's security features in a containerized environment.
> h4. Production Deployments
> With Docker and K8s the old maxim "the devil is in the details" is true in spades. There are dozens of ways that Drill can be configured and integrated in K8s: "stock K8s", OpenShift, AWS EKS, Google GCP and so on. Only experience with users in the field will tell us what is needed. At the same time, we must avoid making the solution too complex: "instant ignition" must be the key, along with additional, optional, config options needed to achieve production deployment goals. This is an area where community contribution would be extremely valuable.
>  



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