This builds various configurations of [OpenSimulator] for running same
in a [Docker] container. The Docker image that is built can include
several different runtime configurations or the OpenSimulator configuration
can be completely replaced at runtime.

## OpenSimulator Image

This builds the latest 'master' version of [OpenSimulator] into a Docker image.
The resulting Docker image has scripts
to run, log, and keep running the [OpenSimulator] instance. The image starts at
`/usr/opensim/bootOpenSim.sh` which checks for initial setup conditions and
then runs `/usr/opensim/run.opensim.sh` which starts [OpenSimulator] using `screen`.

## OpenSimulator Configuration

The [OpenSimulator] setup has a specialized configuration setup. This configuration
setup has:

- the default OpenSimDefault.ini and OpenSim.ini in place
- all of the usual config-include files nulled out (empty)
- a 'bin/config/os-config' file that defines the environment variable 'CONFIG_NAME' which selects the runtime configuration
- the default 'CONFIG_NAME' is 'standalone'
- a set of scripts in 'bin/config' that does the simulation/region configuration

`/usr/opensim/bootOpenSim.sh` calls `/usr/opensim/opensim/bin/config/setup.sh` to
configure this particular [OpenSimulator] instance. `setup.sh` is called everytime
the Docker image is started. `setup.sh` uses `os-config` to define the environment
variable `CONFIG_NAME` and then uses the information in the same named sub-directory
to setup the configuration files for [OpenSimulator].

`bin/config/$CONFIG_NAME/Includes.ini` is copied into `bin/config`. This will be read
by [OpenSimulator] on startup and replaces all of the usual configuration includes.
There will usually be a `bin/config/$CONFIG_NAME/config-includes` that models the
usual [OpenSimulator] configuration directory.

This configuration design means that the complete [OpenSimulator] setup and
runtime configuration can be replaced by replacing the directory
`/usr/opensim/opensim/bin/config`. This allows mounting a configuration directory
for the Docker container to completely replace the setup and configuration.

Note that there are secrets needed to configure and run [OpenSimulator].
These are stored in a 'ccrypt' encrypted file. Read the comments in
'/usr/opensim/opensim/bin/config/os-secrets' for how to encrypt secrets.
The container is initially run with the 'CONFIGKEY' environment variable
which is the key for decrypting the secrets file.

## Building and Running

This is organized so there can be several different runtime configurations
of [OpenSimulator] in this source tree.
The configuration to use is selected by setting the `CONFIG_NAME`
environment variable.

Initially, there are two configuratioms:

- standalone: a simple run of OpenSimulator image in a single docker container using SQLite for the simulator database
- standalone-sql: a configuration that uses MariaDB for the simulator database and can persist the database state between simulator runs

These configurations include all the setup and configuration for the
OpenSimulator instance such as region names and locations.
To create a new configuration, copy the `standalone-mysql` file tree into
a new directory, edit that new set of configuration files, and
do the build and run with your new directory name as `CONFIG_NAME`.

The steps to build and run the containers:

```bash
# Get these configuration files
cd
git clone https://github.com/Misterblue/opensim-docker.git

# Use the standalone setup for this example
cd opensim-docker/opensim-standalone

# Select the runtime configuration to use
export CONFIG_NAME=standalone-sql

# Create secrets
cd config/$CONFIG_NAME
cp ../os-secrets tmpfile
# Edit 'tmpfile' with secrets (MYSQL root password, etc)
ccrypt -e -K secretPassword < tmpfile > os-secrets.crypt
rm tmpfile

# Do any additional OpenSimulator configuration
# Edit 'config/$CONFIG_NAME/Regions/Regions.ini for region location
# Edit 'config/$CONFIG_NAME/misc.ini for other settings
# Edit 'config'$CONFIG_NAME/config-include/*.ini for grid connections

# Build OpenSimulator image
cd
cd opensim-docker/opensim-standalone
./build-standalone.sh

# Run the composed container set
CONFIG_NAME=standalone-mysql CONFIGKEY=secretPassword EXTERNAL_HOSTNAME=whateverTheHostnameIs ./run-standalone.sh

```

[OpenSimulator]: https://opensimulator.org
[Docker]: https://www.docker.com