win32svc

Crystal lang shard which provides support for running a Crystal application as a Windows service.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     win32svc:
       github: lachlan/crystal-win32svc
   

2. Run shards install

Usage

3. Pass a block to Win32::Service.run to run that block as the service logic. The block should either monitor the Win32::Service.started? boolean and exit when it becomes false, or register a block to handle Windows service stop and shutdown events by calling Win32::Service.on_stop, to ensure the service stops when requested by the Windows service controller.

require "win32svc"

# optionally register a block as the stop event handler
Win32::Service.on_stop do
  Log.info { "Service requested to stop" }
  # ...stop running the service
end

# run the service
Win32::Service.run do |args|
  # continue running while service remains started
  while Win32::Service.started?
    # ...run loop for doing stuff...
  end
end

# wait for the service to finish
Win32::Service.await

4. Compile shards build -Dpreview_mt - to run as a Windows Service necessarily requires at least 2 threads: the main thread which is transformed into the service dispatcher, and another thread to run the service itself. For this to work, it requires compiling using the preview_mt flag to enable multithreading in Crystal.

5. Create Windows service

sc create <ServiceName> binpath= <ExecutablePath>
sc config <ServiceName> start= <boot|system|auto|demand|disabled|delayed-auto>
sc config <ServiceName> DisplayName= "<Service Display Name>"
sc description <ServiceName> "<Service Description>"

6. Run Windows service

sc start <ServiceName>
...
sc stop <ServiceName>

Contributing

1. Fork it (https://github.com/lachlan/crystal-win32svc/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Lachlan Dowding - creator and maintainer