pdfkit不呈现来自cdn + rails 4.2 + pdfkit的图像

Question

我正在尝试转换一个html页面，显示图像从facebook cdn到pdf使用pdfkit。我使用的是rails 4.2、pdfkit 0.6.2和wkhtmltopdf-二进制0.9.9.3。

# Gemfile
gem 'pdfkit'
gem 'wkhtmltopdf-binary'

# controller
def generate_pdf
  @booklet = Booklet.find params[:id]
  @cover = Image.last
  @images = @booklet.images.sort_by(&:uploaded_at)
  respond_to do |format|
    format.html
    format.pdf do
      html = render_to_string(layout: true , action: "generate_pdf.html.haml")
      kit = PDFKit.new(html, page_size: 'A4', print_media_type: true)
      kit.stylesheets << "#{Rails.root}/app/assets/stylesheets/application.scss"
      pdf = kit.to_pdf
      send_data pdf, filename: 'booklet.pdf', type: 'application/pdf', disposition: 'inline'
    end
  end
end

# application.scss
@import 'bootstrap';                                                                                                                                           
@import 'custom';
@import 'jquery.booklet';
@import 'bootstrap-datepicker3';

# haml
= link_to 'Download Booklet', generate_pdf_booklet_path(@booklet, format: 'pdf'), class: 'btn btn-primary'

# config/application.rb
require 'pdfkit'
config.middleware.use PDFKit::Middleware

# config/initializers/mime_types.rb
Mime::Type.register "application/pdf", :pdf unless Mime::Type.lookup_by_extension(:pdf)

例如，facebook图像urls是n.jpg?oh=900fe52ecc9b93e044cae4917f538626&oe=559F41E9和o.jpg

当我发送pdf请求时，我在服务器日志上得到以下输出

Rendered booklets/generate_pdf.html.haml within layouts/application   (671.3ms)
QSslSocket: cannot resolve SSLv2_client_method
QSslSocket: cannot resolve SSLv2_server_method
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-e-a.akamaihd.net"
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-e-a.akamaihd.net"
QSslSocket::connectToHostEncrypted() called when already  connecting/connected
QSslSocket::connectToHostEncrypted() called when already connecting/connected
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-b-a.akamaihd.net"
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-b-a.akamaihd.net"
QSslSocket::connectToHostEncrypted() called when already connecting/connected
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-f-a.akamaihd.net"
QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "fbcdn-sphotos-c-a.akamaihd.net"
Rendered text template (0.0ms)
Sent data booklet.pdf (1.4ms)

pdf正在生成，但是本地图像(app/assets/ images )和cdn图像没有呈现在pdf中。此外，样式表没有应用在pdf中。我遗漏了什么？

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已经为上述问题创建了一个示例存储库。这里：https://github.com/prasadsurase/topdf

Answer 1

我终于解决了图像问题。我从Gemfile中删除了wkhtmltopdf -二进制创业板，并将wkhtmltopdf库(版本为0.9.6)安装在框中

sudo apt-get install wkhtmltopdf

不幸的是，我无法在服务器上安装相同的版本。更好的方法是下载二进制文件并将其保存在应用程序中的bin文件夹中，并在pdfkit初始化程序中指定二进制文件的相对位置。这将消除版本问题。，样式表问题仍然存在( .css stylesheets not being applied)

Answer 2

这个问题通常是由QT的SSL库引起的。如果更新wkthmltopdf没有帮助，那么找到合适的libssl-dev版本可能有助于解决这个问题。