78 lines
2.0 KiB
Ruby
78 lines
2.0 KiB
Ruby
# frozen_string_literal: true
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# This module allows us to hijack a request and send it to the client in the deferred job queue
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# For cases where we are making remote calls like onebox or proxying files and so on this helps
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# free up a unicorn worker while the remote IO is happening
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module Hijack
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class Binder
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attr_reader :content_type, :body, :status
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def initialize
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@content_type = 'text/plain'
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@status = 500
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@body = ""
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end
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def render(opts)
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if opts[:status]
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@status = opts[:status].to_i
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else
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@status = 200
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end
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if opts.key?(:body)
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@body = opts[:body].to_s
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end
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if opts.key?(:plain)
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@content_type = 'text/plain; charset=utf-8'
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@body = opts[:plain].to_s
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end
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if opts.key?(:json)
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@content_type = 'application/json; charset=utf-8'
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@body = opts[:json]
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unless String === @body
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@body = @body.to_json
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end
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end
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end
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end
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def hijack(&blk)
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if hijack = request.env['rack.hijack']
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io = hijack.call
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Scheduler::Defer.later("hijack work") do
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begin
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# do this first to confirm we have a working connection
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# before doing any work
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io.write "HTTP/1.1 "
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binder = Binder.new
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begin
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binder.instance_eval(&blk)
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rescue => e
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Rails.logger.warn("Failed to process hijacked response correctly #{e}")
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end
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io.write "#{binder.status} OK\r\n"
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io.write "Content-Length: #{binder.body.bytesize}\r\n"
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io.write "Content-Type: #{binder.content_type}\r\n"
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io.write "Connection: close\r\n"
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io.write "\r\n"
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io.write binder.body
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io.close
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rescue Errno::EPIPE, IOError
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# happens if client terminated before we responded, ignore
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end
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end
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# not leaked out, we use 418 ... I am a teapot to denote that we are hijacked
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render plain: "", status: 418
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else
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blk.call
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end
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end
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end
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