Class: Aspera::Faspex4PostProcServlet

Inherits:
WEBrick::HTTPServlet::AbstractServlet
  • Object
show all
Defined in:
lib/aspera/faspex_postproc.rb

Overview

Start a Faspex-4 style post-processing script using Faspex-5 webhook

Constant Summary collapse

ALLOWED_PARAMETERS = 
%i[root script_folder fail_on_error timeout_seconds].freeze

Instance Method Summary collapse

Constructor Details

#initialize(server, parameters) ⇒ Faspex4PostProcServlet

Returns a new instance of Faspex4PostProcServlet.



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# File 'lib/aspera/faspex_postproc.rb', line 15

def initialize(server, parameters)
  Aspera.assert_type(parameters, Hash)
  @parameters = parameters.symbolize_keys
  Log.dump(:post_proc_parameters, @parameters)
  not_allowed = @parameters.keys - ALLOWED_PARAMETERS
  Aspera.assert(not_allowed.empty?) { "unsupported parameters: #{not_allowed.join(', ')}" }
  @parameters[:script_folder] ||= '.'
  @parameters[:fail_on_error] ||= false
  @parameters[:timeout_seconds] ||= 60
  super(server)
  Log.log.debug { 'Faspex4PostProcServlet initialized' }
end

Instance Method Details

#do_POST(request, response) ⇒ Object

:reek:UncommunicativeMethodName



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# File 'lib/aspera/faspex_postproc.rb', line 29

def do_POST(request, response)
  Log.log.debug { "request=#{request.path}" }
  Log.dump(:query, request.query)
  begin
    # Only accept requests on the root
    if !request.path.start_with?(@parameters[:root])
      response.status = 400
      response['Content-Type'] = Mime::JSON
      response.body = {status: 'error', message: 'Request outside domain'}.to_json
      return
    end
    if request.body.nil?
      response.status = 400
      response['Content-Type'] = Mime::JSON
      response.body = {status: 'error', message: 'Empty request'}.to_json
      return
    end
    # build script path by removing domain and adding script folder
    script_file = request.path[@parameters[:root].size..]
    Log.log.debug { "script file=#{script_file}" }
    script_path = File.join(@parameters[:script_folder], script_file)
    # Resolve the real path and ensure it stays within script_folder (prevents path traversal)
    resolved_script_folder = File.realpath(@parameters[:script_folder])
    resolved_script_path = File.realpath(script_path)
    Aspera.assert(resolved_script_path.start_with?("#{resolved_script_folder}/")) { 'Script path traversal attempt detected' }
    script_path = resolved_script_path
    Log.log.debug { "script=#{script_path}" }
    webhook_parameters = JSON.parse(request.body)
    Log.dump(:webhook_parameters, webhook_parameters)
    process_status = nil
    if request.query.key?('lambda')
      # Code can throw exception, source code must return a lambda
      Environment.secure_eval(File.read(script_path), __FILE__, __LINE__).call(webhook_parameters)
    else
      # env expects only strings
      environment = webhook_parameters.each_with_object({}) { |(k, v), h| h[k] = v.to_s }
      post_proc_pid = Environment.secure_execute(script_path, mode: :background, env: environment)
      Timeout.timeout(@parameters[:timeout_seconds]) do
        # "wait" for process to avoid zombie
        Process.wait(post_proc_pid)
        post_proc_pid = nil
      end
      process_status = $CHILD_STATUS
      Aspera.assert(process_status.success? || !@parameters[:fail_on_error]) { "script #{script_path} failed with code #{process_status.exitstatus}" }
    end
    response.status = 200
    response.content_type = Mime::JSON
    response.body = JSON.generate({status: 'success', script: script_path, exit_code: process_status&.exitstatus})
    Log.log.debug { 'Script executed successfully' }
  rescue => e
    Log.log.error("Script failed: #{e.class}:#{e.message}")
    if !post_proc_pid.nil?
      Process.kill('SIGKILL', post_proc_pid)
      Process.wait(post_proc_pid)
      Log.log.error("Killed process: #{post_proc_pid}")
    end
    response.status = 500
    response['Content-Type'] = Mime::JSON
    response.body = {status: 'error', script: script_path, message: e.message}.to_json
  end
end