Docker Guide
============

Docker is a tool that allows for the creation of containers, which are isolated environments that can
be used to run applications. They are useful for ensuring that an application can run on any machine
that has Docker installed, regardless of the host machine's operating system or installed libraries.

We include a Dockerfile and docker-compose.yaml file that can be used to build a Docker image that
contains Orbit and all of its dependencies. This image can then be used to run Orbit in a container.
The Dockerfile is based on the Isaac Sim image provided by NVIDIA, which includes the Omniverse
application launcher and the Isaac Sim application. The Dockerfile installs Orbit and its dependencies
on top of this image.

.. caution::

    Due to the dependency on Isaac Sim docker image, by running this container you are implicitly
    agreeing to the `NVIDIA Omniverse EULA`_. If you do not agree to the EULA, do not run this container.

Setup Instructions
------------------

.. note::

    The following steps are taken from the NVIDIA Omniverse Isaac Sim documentation on `container installation`_.
    They have been added here for the sake of completeness.


Docker and Docker Compose
~~~~~~~~~~~~~~~~~~~~~~~~~

We have tested the container using Docker Engine version 24.0.2 and Docker Compose version 2.18.1.
We recommend using these versions or newer.

* To install Docker, please follow the instructions for your operating system on the `Docker website`_.
* To install Docker Compose, please follow the instructions for your operating system on the `docker-compose`_ page.
* Follow the post-installation steps for Docker on the `post-installation steps`_ page. These steps allow you to run
  Docker without using ``sudo``.
* To build and run GPU-accelerated containers, you also need install the `NVIDIA Container Toolkit`_.
  Please follow the instructions on the `Container Toolkit website`_ for installation steps.


Obtaining the Isaac Sim Container
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Get access to the `Isaac Sim container`_ by joining the NVIDIA Developer Program credentials.
* Generate your `NGC API key`_ to access locked container images from NVIDIA GPU Cloud (NGC).

  * This step requires you to create an NGC account if you do not already have one.
  * You would also need to install the NGC CLI to perform operations from the command line.
  * Once you have your generated API key and have installed the NGC CLI, you need to log in to NGC
    from the terminal.

    .. code:: bash

        ngc config set

* Use the command line to pull the Isaac Sim container image from NGC.

  .. code:: bash

      docker login nvcr.io

  * For the username, enter ``$oauthtoken`` exactly as shown. It is a special username that is used to
    authenticate with NGC.

    .. code:: text

        Username: $oauthtoken
        Password: <Your NGC API Key>


Directory Organization
----------------------

The root of the Orbit repository contains the ``docker`` directory that has various files and scripts
needed to run Orbit inside a Docker container. These are summarized below:

* ``Dockerfile``: Defines orbit image by overlaying Orbit dependencies onto the Isaac Sim Docker image.
* ``docker-compose.yaml``: Creates mounts to allow direct editing of Orbit code from the host machine that runs
  the container along with X11 forwarding. It also creates several named volumes such as ``isaac-cache`` to store frequently
  re-used resources compiled by Isaac Sim, such as shaders, and to retain logs, data, and documents.
* ``.env``: Stores environment variables required for the build process and the container itself.
* ``container.sh``: A script that wraps the ``docker-compose`` command to build the image and run the container.

Running the Container
---------------------

.. note::

    The docker container copies all the files from the repository into the container at the
    location ``/workspace/orbit``. This means that any changes made to the files in the container will not
    be reflected in the repository.

    To deal with this, we mount the following directories in the Orbit repository into the container
    so that you can edit their files from the host machine:

    * ``source``: This is the directory that contains the Orbit source code.
    * ``docs``: This is the directory that contains the source code for Orbit documentation. This is overlaid except
      for the ``_build`` subdirectory where build artifacts are stored.


The script ``container.sh`` wraps around three basic ``docker-compose`` commands:

1. ``start``: This builds the image and brings up the container in detached mode (i.e. in the background).
2. ``enter``: This begins a new bash process in an existing orbit container, and which can be exited
   without bringing down the container.
3. ``copy``: This copies the ``logs`` and ``docs/_build`` artifacts, from the ``orbit-logs`` and ``orbit-docs``
   volumes respectively, to the ``docker/artifacts`` directory. These artifacts persist between docker
   container instances.
4. ``stop``: This brings down the container and removes it.

Following shows how to launch the container in a detached state and enter it:

.. code:: bash

    # Launch the container in detached mode
    ./docker/container.sh start
    # Enter the container
    ./docker/container.sh enter

To copy files from the container to the host machine, you can use the following command:

.. code:: bash

    # Copy the file /workspace/orbit/logs to the current directory
    docker cp orbit:/workspace/orbit/logs .

The script ``container.sh`` provides a wrapper around this command to copy the ``logs`` and ``docs/_build``
directories to the ``docker/artifacts`` directory. This is useful for copying the logs and documentation:

.. code:: bash

    # Copy the logs and docs/_build directories to the docker/artifacts directory
    ./docker/container.sh copy

To stop the container, you can use the following command:

.. code:: bash

    # stop the container
    ./docker/container.sh stop


Frequently Asked Questions
--------------------------

Python Interpreter
~~~~~~~~~~~~~~~~~~

The container uses the Python interpreter provided by Isaac Sim. This interpreter is located at
``/isaac-sim/python.sh``. We set aliases inside the container to make it easier to run the Python
interpreter. You can use the following commands to run the Python interpreter:

.. code:: bash

    # Run the Python interpreter -> points to /isaac-sim/python.sh
    python


Understanding the mounted volumes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``docker-compose.yaml`` file creates several named volumes that are mounted to the container.
These are summarized below:

* ``isaac-cache``: This volume is used to store frequently re-used resources compiled by Omniverse, such as shaders.
* ``isaac-logs``: This volume is used to store logs generated by Omniverse.
* ``isaac-data``: This volume is used to store data generated by Omniverse.
* ``isaac-docs``: This volume is used to store documents generated by Omniverse.
* ``orbit-docs``: This volume is used to store documentation of Orbit when built inside the container.
* ``orbit-logs``: This volume is used to store logs generated by Orbit workflows when ran inside the container.

To view the contents of these volumes, you can use the following command:

.. code:: bash

    # list all volumes
    docker volume ls
    # inspect a specific volume, e.g. isaac-cache
    docker volume inspect isaac-cache


Invalid mount config for type "bind"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you see the following error when building the container:

.. code:: text

    ⠋ Container orbit  Creating                                                                                                                                                                         0.0s
    Error response from daemon: invalid mount config for type "bind": bind source path does not exist: ${HOME}/.Xauthority

This means that the ``.Xauthority`` file is not present in the home directory of the host machine.
This file is required for X11 forwarding to work. To fix this, you can create an empty ``.Xauthority``
file in your home directory.

.. code:: bash

    touch ${HOME}/.Xauthority

A similar error but requires a different fix:

.. code:: text

    ⠋ Container orbit  Creating                                                                                                                                                                         0.0s
    Error response from daemon: invalid mount config for type "bind": bind source path does not exist: /tmp/.X11-unix

This means that the folder/files are either not present or not accessible on the host machine. This usually happens
when you have multiple docker versions installed on your machine. To fix this, you can try the following:

* Remove all docker versions from your machine.

  .. code:: bash

      sudo apt remove docker*
      sudo apt remove docker docker-engine docker.io containerd runc docker-desktop docker-compose-plugin
      sudo snap remove docker
      sudo apt clean autoclean && sudo apt autoremove --yes

* Install the latest version of docker based on the instructions in the setup section.


Known Issues
------------

WebRTC and WebSocket Streaming
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When streaming the GUI from Isaac Sim, there are `several options`_ available. There is a `known issue`_ when
attempting to use WebRTC streaming client on Google Chrome and Safari while running Isaac Sim inside a container.
To avoid this problem, we suggest using either the Native Streaming Client or WebSocket options, or using the
Mozilla Firefox browser on which WebRTC works.


.. _`NVIDIA Omniverse EULA`: https://docs.omniverse.nvidia.com/app_isaacsim/common/NVIDIA_Omniverse_License_Agreement.html
.. _`container installation`: https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/install_container.html
.. _`Docker website`: https://docs.docker.com/desktop/install/linux-install/
.. _`docker-compose`: https://docs.docker.com/compose/install/linux/#install-using-the-repository
.. _`NVIDIA Container Toolkit`: https://github.com/NVIDIA/nvidia-container-toolkit
.. _`Container Toolkit website`: https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html
.. _`post-installation steps`: https://docs.docker.com/engine/install/linux-postinstall/
.. _`Isaac Sim container`: https://catalog.ngc.nvidia.com/orgs/nvidia/containers/isaac-sim
.. _`NGC API key`: https://docs.nvidia.com/ngc/gpu-cloud/ngc-user-guide/index.html#generating-api-key
.. _several options: https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/manual_livestream_clients.html
.. _known issue: https://forums.developer.nvidia.com/t/unable-to-use-webrtc-when-i-run-runheadless-webrtc-sh-in-remote-headless-container/222916
