capistrano-kemal.rb

lock '3.5.0'

set :application, 'your-app'
set :repo_url, 'https://github.com/your/app'
set :deploy_to, '/home/deploy/apps/your-app/'

namespace :deploy do
  after :updated, :build do
    on roles(:web) do
    	execute "cd '#{release_path}' && shards install"
	    execute "cd '#{release_path}' && crystal build --release src/app.cr"
    end
  end
end

namespace :kemal do
	task :start do
  	on roles(:web) do
  		execute "#{release_path}/app >> #{shared_path}/kemal.log & echo $! > #{shared_path}/kemal.pid"
  	end
	 end

	task :restart do
    on roles(:web) do
      invoke "kemal:stop"
      invoke "kemal:start"
    end    
  end

  task :stop do
    on roles(:web) do
      execute "kill -INT $(cat #{shared_path}/kemal.pid) && rm #{shared_path}/kemal.pid"
    end    
  end
end

after 'deploy:publishing', 'kemal:restart'