OpenSimulator

From the OpenSimulator site:

OpenSimulator is an open source multi-platform, multi-user 3D application server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols.

This unofficial Docker configuration aims to assist in setting the server up for testing and general purpose use.

This is still experimental - thar be bugs!

Important

Mono has been discontinued - for the foreseeable 0.9.2.2 and below images will not be updated. Until a maintainer or suitable alternative is found, they are not supported.

Warning

0.9.3.0 (and in turn latest) is a significant change from 0.9.2.2 and below. Mono is no longer used, and has been replaced with the .NET Framework. This changes some aspects of the image, such as the ENTRYPOINT and source builds, so please test before switching over. If you wish to remain, 0.9.2.2 will continue to be updated and remains on the Mono base. For more information, see the official release notes and this PR for Dockerfile changes.

Supported tags and respective Dockerfile links

• latest, 0.9, 0.9.3, 0.9.3.0

• 0.9.3-noscreen, 0.9.3.0-noscreen

• 0.9.2, 0.9.2.2 (unsupported)

• 0.9.2.1 (unsupported)

• source (unsupported)

• alpine-beta

Usage

docker run -d --name opensim -p 9000:9000 -p 9000:9000/udp soupbowl/opensimulator:latest

You can change settings with the following optional environmental overrides:

• -e GRID_NAME=... to define the name of your grid.
• -e GRID_WELCOME=... to show a custom message on the login screen.
• -e REGION_NAME=... to define the Region name.
• -e ESTATE_NAME=... to define the Estate name.
• -e ESTATE_OWNER_NAME=... to set the estate owner name (and creates a login) - format of 'Firstname Lastname'.
• -e ESTATE_OWNER_PASSWORD=... to define a login password.
• -e ESTATE_OWNER_UUID=... for a custom UUID, if desired.
• -e ESTATE_OWNER_EMAIL=... to define the estate email address.
• -e DATABASE_ENGINE=... to change the database engine (sqlite and mysql support so far) - defaults to sqlite.
• -e MYSQL_SERVER=..., -e MYSQL_DATABASE=..., -e MYSQL_USER=..., -e MYSQL_PASSWORD=... if DATABASE_ENGINE is mysql.
• -e PHYSICS_ENGINE=... to change the physics engine. Default is BulletSim with others being OpenDynamicsEngine, ubODE and basicphysics.

Once the server is running, you should be able to connect to it on localhost:9000. In Firestorm Viewer, you can go to Preferences, then Opensim, then under add new grid put localhost:9000 and you can then login.

If you don't define otherwise in the environments or a custom configuration, the login username is Foo bar and the password is password.

Custom Configurations

The environment list is not inclusive to the incredible range of options that OpenSimulator can be configured, and just covers a subset of the most popular settings. If you specify your own custom configuration file, it will be used instead of the image-generated configuration (you can define it as readonly (:ro) for assurance).

The working directory is /opt/opensim/bin/, so for example overriding OpenSim.ini would be "/path/to/local/OpenSim.ini:/opt/opensim/bin/OpenSim.ini:ro" (example).

SQLite Persistence

Outside of configurations, pretty much everything OpenSimulator does is stored in your chosen database provider. If you choose to leave the default on (sqlite), then your installation will not persist if you remove your container.

To aid the use of SQLite mode with persistent data, the default configuration has been modified to create the database directories into a dedicated directory (/opt/opensim/bin/sqlite-database). The following command will allow you to run a persistent SQLite setup.

(Note that if you use a custom SQLiteStandalone.ini file, this will not happen).

docker run -d --name opensim -p 9000:9000 -p 9000:9000/udp -v /path/on/your/system:/opt/opensim/bin/sqlite-database  soupbowl/opensimulator:latest

Limitations

Running Server Admin Commands

At current, there doesn't appear to be an implemented and/or documented approach to managing the server from outside the active TTY, and running docker attach opensim seems to produce a blank prompt. You can exec into the container or edit the bound configuration script and restart the server to make changes, but in some server instances you might need to intercept the prompt.

This Docker image comes with screen built in, to allow you to access the administration prompt. This also seems to help prevent against Docker from accidentally destroying the image (currently investigating). As a result this leaves the Docker log unfortunately blank, but you can access the logfile at /opt/opensim/bin/OpenSim.log.

You can access a controllable OpenSimulator administration prompt by running:

docker exec -it <container name> screen -r -d OpenSim

You can leave the screen session by pressing ctrl + a then d.

If you wish to run without, you can modify the Dockerfile like so:

FROM soupbowl/opensimulator:latest
CMD [ "dotnet",  "OpenSim.dll" ]

Physics in ARM

Each image has an ARM64 architecture build. Your mileage may vary with these as the server environment was not designed for use outside x86_64.

Currently, Physics environments do not appear to be natively supported, and running a server with BulletSim or OpenDynamicsEngine (ODE) will cause a fatal exception. You unfortunately currently have to run the server without physics. This can be achieved by setting the environment -e PHYSICS_ENGINE=basicphysics, or with the following OpenSim configuration adjustment:

[Startup]
   physics = basicphysics

Alternatively, a suitable drop-in library in lib64/libBulletSim-aarch64.so for BulletSim Physics could work, but may be unsupported.

I'm keen to support ARM architecture to the bounds of OpenSimulator. If you have any experience on this, please reach out to me.

Examples

See this repository for some example usages of this image.

Variants

Variant names are listed in Dockerhub format. They are also available from the GitHub Registry, replacing soupbowl/opensimulator with ghcr.io/soup-bowl/opensimulator-docker.

soupbowl/opensimulator:latest

The latest OpenSimulator image build using official .NET 8 image as the build reference.

If you pull from 0.9.2.2 or below, you will instead be using the Mono Framework. As of August 2025 these are not supported as Mono framework has been discontinued.

soupbowl/opensimulator:<version>-noscreen

Starting from 0.9.3.0, until #9 is resolved, there is a build of the Dotnet editions without screen. This is temporary and will be removed once a solution is found, so there is no latest tag to avoid dependency. All feedback on experience is welcome on issue #9.

soupbowl/opensimulator:alpine-beta

A bleeding edge variant using Alpine as the build image. Progress can be tracked on the #1 ticket.

This will be revised/removed since OpenSimulator have moved away from Mono.

soupbowl/opensimulator:source

Gets the latest available code from the OpenSimulator repository, and constructs a bleeding edge container. Configuration is not different, but this is compiled from source and should be treated as highly unstable. These are built on demand, when a detected changre has occurred.

Source Code

The source code of the Docker image is found on the GitHub repository. You can find the OpenSimulator server software source code on their website.