hadoop/hadoop-hdds/docs/content/beyond/DockerCheatSheet.md

---
title: "Docker Cheat Sheet"
date: 2017-08-10
summary: Docker Compose cheat sheet to help you remember the common commands to control an Ozone cluster running on top of Docker.
weight: 4
---

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In the `compose` directory of the ozone distribution there are multiple pseudo-cluster setup which
can be used to run Ozone in different way (for example: secure cluster, with tracing enabled,
with prometheus etc.).

If the usage is not document in a specific directory the default usage is the following:

```bash
cd compose/ozone
docker-compose up -d
```

The data of the container is ephemeral and deleted together with the docker volumes.
```bash
docker-compose down
```

## Useful Docker & Ozone Commands

If you make any modifications to ozone, the simplest way to test it is to run freon and unit tests.

Here are the instructions to run freon in a docker-based cluster.

{{< highlight bash >}}
docker-compose exec datanode bash
{{< /highlight >}}

This will open a bash shell on the data node container.
Now we can execute freon for load generation.

{{< highlight bash >}}
ozone freon randomkeys --numOfVolumes=10 --numOfBuckets 10 --numOfKeys 10
{{< /highlight >}}

Here is a set of helpful commands for working with docker for ozone.
To check the status of the components:

{{< highlight bash >}}
docker-compose ps
{{< /highlight >}}

To get logs from a specific node/service:

{{< highlight bash >}}
docker-compose logs scm
{{< /highlight >}}


As the WebUI ports are forwarded to the external machine, you can check the web UI:

* For the Storage Container Manager: http://localhost:9876
* For the Ozone Manager: http://localhost:9874
* For the Datanode: check the port with `docker ps` (as there could be multiple data nodes, ports are mapped to the ephemeral port range)

You can start multiple data nodes with:

{{< highlight bash >}}
docker-compose scale datanode=3
{{< /highlight >}}

You can test the commands from the [Ozone CLI]({{< ref "shell/_index.md" >}}) after opening a new bash shell in one of the containers:

{{< highlight bash >}}
docker-compose exec datanode bash
{{< /highlight >}}