tractor-docker

Run Pixar's Tractor using Docker containers.

A Docker Compose file will create a series of containers which are all based on the same Docker image:

• pixar-license - the Pixar License server, required for Tractor to dispatch work
• tractor-data - persistent database data in Docker volume and configuration data mapped onto Docker host
• tractor-engine - the Tractor Engine server
• tractor-blade - a Tractor Blade

Jeez... ok, so how does this work?

Basically, this will set up everything which is required for Tractor to run, provided you can bring your own RPMs and license (you're a Pixar Tractor customer).

It's really not that complicated. First, check out the Dockerfile. We create all containers based on this. Then check out docker-compose.yml on which command is being run for each container. That's it, with wide brush strokes, really.

Notes on customizing the implementation

You may want to change the licensing approach. Maybe you already have a Pixar License Server running somewhere in your network. In this case, you can omit the license container block in docker-compose.yml and add the 9010 port to the engine container block.

You may also want to change the behavior of the Docker volume which holds the Tractor Engine database data. The recommended approach by Docker is to generally keep database data persistent, so that it doesn't get deleted if the container is restarted. You might wish to map such a Docker volume to an actual location on the Docker host. This will require that the non-root Tractor user (default: farmer) exist on the Docker host.

Using the default container setup, the local assets folder contents is mapped to the containers (see docker-compose.yml for details). This makes it easy to access the configuration, the license file, logs etc from the host running the containers as well as from within the containers.

The tractor-blade currently isn't really doing any good and is only supposed to exist to show an example implementation. You might want to base this off another Docker image, or equip the existing Tractor Docker image with additional software. Maybe you you would rather run a Tractor blade from within the tractor-engine container, and in that case you can use the provided supervisor command and look at assets/etc/supervisor/supervisord.conf for more info. Please note that you shouldn't define a hostname for the tractor-blade container if you plan on scaling this container using e.g. docker-compose blade scale=10. If you do this, all such blades will share the same hostname and only one blade will show in Tractor Engine. Also, if you wish to scale the blade service, you must comment out its container_name attribute in docker-compose.yml.

Please note that if you rename the tractor-docker directory, the quickstart below will fail.

Quickstart

1. Download the project:

git clone https://github.com/fredrikaverpil/tractor-docker.git

2. Prepare the RPMs, Pixar license and Tractor configuration.

• Put the Tractor and PixarLicense server RPMs in tractor-docker/assets/opt/pixar/rpms.
• Put your pixar.license file into the tractor-docker/assets/opt/pixar/license folder.
• Copy your Tractor configuration into the tractor-docker/assets/opt/pixar/config folder.

3. Verify Dockerfile

• Verify that the COPY statements of tractor-docker/Dockerfile contains the correct RPM filenames.
• Verify that the RUN useradd statement of tractor-docker/Dockerfile creates the desired (non-root) Tractor user (default: farmer).

4. Verify docker-compose.yml

• Verify each command statement in docker-compose.yml to reflect the correct filepath to PixarLicenseServer, tractor-engine and tractor-blade.

5. Verify tractor.config

• Verify that the EngineOwner in tractor-docker/assets/tractor.config uses the desired (non-root) Tractor user (default: farmer).
• Verify so that LicenseLocation points to /opt/pixar/license/pixar.license.

6. Build the container image

This will build the container image tractor-image.

cd tractor-docker
docker-compose build

Please note that if you have a large Tractor database already (perhaps you are upgrading), the build command will take ages. Therefore move the database temporarily out of the tractor-docker folder tree prior to building.

7. Run the compose

This will create and start the pixar-license, tractor-data, tractor-engine and tractor-blade containers based on the tractor-image container image.

cd tractor-docker
docker-compose up

8. Figure out the IP address used to access the Tractor Engine

docker inspect tractor-engine | grep IPAddress

9. Stop all containers

cd tractor-docker
docker-compose stop

Useful commands

Enter a running container

docker exec -i -t CONTAINER_NAME /bin/bash

List all running containers

docker ps # or 'docker ps -a' for all containers

Remove the data container along with its volume data

docker rm -v tractor-data

Backup Docker volume data (Tractor database)

This will back up the entire Tractor database to /backup/backup.tar, while tractor-docker is running.

docker run --rm --volumes-from tractor-data -v $(pwd):/backup centos tar cvf /backup/backup.tar /var/spool/tractor

To-do

• Implement tractor-purge of old task logs and old jobs to avoid running out of disk space too quickly...