Configuration
xds-agent configuration is driven by a JSON config file.
The tarball mentioned in previous section includes this file with default settings.
Here is the logic to determine which conf file will be used:
- from command line option: 
--config myConfig.json $HOME/.xds/agent/agent-config.jsonfile/etc/xds/agent/agent-config.jsonfile
Supported fields in configuration file are (all fields are optional and example below corresponds to the default values):
- httpPort : http port of agent REST interface
 - webAppDir : location of client webapp / dashboard (default: webapp/dist)
 - logsDir : directory to store logs (eg. syncthing output)
 - xdsServers : an array of xds-server object
 - xdsServers.url: url of xds-server to connect to
 - syncthing: a object defining syncthing settings
 - syncthing.binDir : syncthing binaries directory (default: executable directory)
 - syncthing.home" : syncthing home directory (usually .../syncthing-config)
 - syncthing.gui-address : syncthing gui url (default http://localhost:8386)
 - syncthing.gui-apikey : syncthing api-key to use (default auto-generated)
 
{
    "httpPort": "8800",
    "webAppDir": "./www",
    "logsDir": "${HOME}/.xds/agent/logs",
    "xdsServers": [
        {
          "url": "http://localhost:8000"
        }
    ],
    "syncthing": {
        "home": "${HOME}/.xds/agent/syncthing-config",
        "gui-address": "http://localhost:8386",
        "gui-apikey": "1234abcezam"
    }
}
Note:
environment variables are supported by using
${MY_VAR}syntax.