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

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

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 with secure cluster, with tracing enabled, with prometheus etc.).

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

cd compose/ozone
docker-compose up -d

The data of the container is ephemeral and deleted together with the docker volumes. To force the deletion of existing data you can always delete all the temporary data:

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 >}}