The FairCom EDGE database ships with many plug-ins, which extend its capabilities. They provide the database with the ability to communicate over HTTP, MQTT, OPC UA, REST, ThingWorx AlwaysOn, etc.
Each plug-in is independently enabled and configured with a plug-in based architecture. They are not enabled by default to maximize security. (Plug-ins are secure, but they increase the attack surface by opening extra network ports and listening across more communication protocols.)
The ctsrvr.cfg configuration file contains a list of plug-ins that run when the database starts. This file is located in c-treeEDGE-Installation-Folder\server\config.
The example below shows the plug-in section of the ctsrvr.cfg configuration file on a Linux server:
In this example, the first plug-in is cthttpd. This is the HTTP plug-in that enables the IIoT Hub’s HTTP protocol, web services, and MQTT services. Following the keyword PLUGIN is the name of the folder containing the plug-in’s configuration file. The configuration file must have the same name as the plug-in’s folder but with the .json extension. In the example above, the name of the plug-in folder is cthttpd and this folder contains a configuration file named cthttpd.json.
All plug-in folders must be located in the FairCom EDGE Server working directory (for example c-treeEDGE-Installation-Folder\server). You will see the plug-in sub-folders in this location (for example .\web, .\opc, etc.).
A semicolon must follow the name of the plug-in’s folder.
Following the semicolon is the relative file system path to the plug-in’s executable. The path is relative to the folder that contains the plug-in.
In the example above, ./web/libcthttpd.so is the relative path to the plug-in’s executable, which is named libcthttpd.so.
On Microsoft Windows, a plug-in is a Dynamic Linked Library with the extension of .dll. On Linux, a plug-in is a shared object library with the extension of .so. On MacOS, a plug-in is a dynamic library with an extension of .dylib.
To disable a plug-in, put a semicolon (;) before the keyword PLUGIN. To enable a plug-in, remove the semicolon.
Contact FairCom support to request new types of general-use plug-ins. FairCom Professional services can build custom plug-ins for you. You can also build your own plug-ins with help from FairCom support.
All Plug-In Settings and Config Files in config Directory by Default
By default, all of the current plug-ins' settings files and configuration are loaded from the config directory. This applies to Replication Manager, web server, ThingWorx, OPC, and Automatic System Time/TimeStamp) settings files.
Best Practice: User-created plug-ins do not have to follow this practice, because they can be written to load their settings from wherever they want. However, for consistence and simplicity of administration, it is strongly recommended as a best practice to place all settings files in the config directory.