barn is a ASCOM Alpaca compatible safety monitor driver, allowing you to expose local files or remote URLs as ASCOM compatible safety monitor devices.

Running

There are no compiled binaries provided (for now), but you can use docker to run barn.

Using docker compose:

Place barn.yaml file into cloned directory and run:

docker compose up -d

Or using just docker:

Build image:

docker build . -t barn

And then run it, adjust ports and config file path if necessary:

docker run -p8080:8080 -p32227:32227/udp -it -v <Full path to config file>/barn.yaml:/barn.yaml barn

Configuration

Configuration file should be named barn.yaml and goes into same directory as barn binary. Below is an example configuration file to showcase the capabilities of barn.

api: # (optional)
  port: 8080 # Api port. 8080 by default
discovery: # (optional)
  port: 32227 #Alpaca discovery port. 32227 by default
monitors: # (mandatory)
  http: # Define HTTP safety monitors
    remote: # Monitor ID should be unique
      name: "Some remote url" # Safety monitor name
      description: "Some remote url description" # Description
      url: http://127.0.0.1/test # Url to check
    remote2:
      name: "Second remote url"
      description: "Second remote url description"
      url: http://127.0.0.2/test
  file: # Define local file safety monitor
    local: 
      name: "Local file" 
      description: "Some local file description"
      path: /tmp/test # File path to check
  dummy: # Fake safety monitors (Stays always in defined state) 
    fake:
      is_safe: true # State of the monitor

Rules

By default, barn matches 1 or true (case-insensitive) as "safe". You can customize that behaviour with following configuration

monitors:
  http:
    remote:
      name: "Some remote url"
      description: "Some remote url description"
      url: http://127.0.0.1/test
      rule:
        invert: false # Invert matching result (if pattern key exists applied after match) 
        pattern: "(open|opening)" # Regular expression to match

Todo

• JSON support.