Iamus

Metaverse server for Vircadia Project that integrates the virtual world with ActivityPub.

Running

The configuration of the metaverse-server is controlled by parameters that are defined and defaulted in config.ts. These default values are over-ridden by some environment variables and then by the contents of a configuration file.

The usual setup is to do all the configuration setup in the configuration file, setting the environment variable to point at that configuration file, and then running the metaverse-server.

Environment variables, if they exist, override default values:

IAMUS_LOGLEVEL: logging level. One of 'error', 'info', 'warn', 'debug'. Default 'info'.
IAMUS_LISTEN_HOST: host to listen for requests on. Default '0.0.0.0'.
IAMUS_LISTEN_PORT: port to listen for requests on. Default 9400.
IAMUS_EXTERNAL_HOSTNAME: hostname to report as referencing back to this server. This is mostly used by ActivityPub for links to users. Default 'localhost'. This value MUST be set for proper metavserse-server operation.
IAMUS_CONFIG_FILE: filename or URL of a JSON formatted configuration file that over-rides the values. Default "./imus.json".

Building

Architecture/Organization

Routing

ExpressJS routing is built at run time. The routine createAPIRouter() in index.ts imports all the .js files in the given directory and, if they present a Router export, that route is added to a new router. This builds a router that routes to all the routers defined in the directory tree.

Each of the processors for MetaverseAPI requests is processed as a stream with processors for setting up the actual action of the request. The parameters for the final action are variables added to the passed request. See RequestAdditions.ts for the definition of the additional variables added to the Request object.

As an example:

router.delete('/api/v1/account/:accountId/tokens/:tokenId',
                    [ setupMetaverseAPI,      // req.vRestReq
                      accountFromAuthToken,   // req.vAuthAccount
                      accountFromParams,      // req.vAccount
                      tokenFromParams,        // req.vToken
                      procDeleteToken,
                      finishMetaverseAPI
                    ] );

For this request, setupMetaverseAPI sets up the passed Request with initial values (mostly setup for the status/data eventual response). Then accountFromAuthToken looks up the account specified in the Authorization: header and sets the value on req.vAuthAccount. Then accountFromParams looks up the account specified in the :accountId URL parameter and sets req.vAccount. tokenFromParams does the token lookup for the :tokenId parameter. Then procDeleteToken is called which actually does the delete operation based on all the collected parameters. Finally, finishMetaverseAPI builds the status/data response for the request.

Other Implimentation Nodes

So that the import statements don't have relative file references, this uses path aliases. These start with at-signs and are defined in tsconfig.json and package.json. The module-alias package is used to set the paths in the compiled JavaScript code. This package is invoked at the top of index.ts;

MarcusLlewellyn / Iamus