docker 构建错误 Gem::Ext::BuildError: 错误：无法为 mimemagic-0.3.9 构建 gem 原生扩展

Question

我必须在本地计算机上构建 docker 映像以验证它是否是在构建映像，但是在本地计算机上构建 docker 映像时遇到了这个问题。

 Installing mime magic 0.3.9 with native extensions
    Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /usr/local/bundle/gems/mimemagic-0.3.9/ext/mimemagic
/usr/local/bin/ruby -I/usr/local/lib/ruby/2.7.0/rubygems -rrubygems
/usr/local/lib/ruby/gems/2.7.0/gems/rake-13.0.1/exe/rake
RUBYARCHDIR\=/usr/local/bundle/extensions/x86_64-linux/2.7.0/mimemagic-0.3.9
RUBYLIBDIR\=/usr/local/bundle/extensions/x86_64-linux/2.7.0/mimemagic-0.3.9
rake aborted!
Could not find MIME type database in the following locations:
["/usr/local/share/mime/packages/freedesktop.org.xml",
"/opt/homebrew/share/mime/packages/freedesktop.org.xml",
"/usr/share/mime/packages/freedesktop.org.xml"]


/usr/local/bundle/gems/mimemagic-0.3.9/ext/mimemagic/Rakefile:25:in `block in
<top (required)>'
Tasks: TOP => default
(See full trace by running task with --trace)

rake failed, exit code 1

Gem files will remain installed in /usr/local/bundle/gems/mimemagic-0.3.9 for
inspection.
Results logged to
/usr/local/bundle/extensions/x86_64-linux/2.7.0/mimemagic-0.3.9/gem_make.out

An error occurred while installing mimemagic (0.3.9), and Bundler cannot
continue.
Make sure that `gem install mimemagic -v '0.3.9' --source
'https://rubygems.org/'` succeeds before bundling.

Answer 1

1. 修改Dockerfile以安装shared-mime-info package。 例如在基于 Debian 的图像上：

   RUN apt-get update && apt-get install -y shared-mime-info

2. 如果它仍然不起作用，那么您可能需要更新mimemagic gem。 在您的主机上，更新 Rails 应用程序的Gemfile / mimemagic中的Gemfile.lock 。 您可能需要先安装shared-mime-info ：如果主机是 macOS，您可能需要运行brew install shared-mime-info ； 如果主机是 Ubuntu，您可能需要运行apt-get install shared-mime-info 。 然后运行

   bundle update mimemagic

3. 如果您的Dockerfile从存储库下载 Rails 应用程序，请先将更改推送到该存储库。 或者，为了测试，修改Dockerfile以从主机复制到 Rails 应用程序中。

Answer 2

如果您使用的是 macOS，请尝试以下操作

 brew install shared-mime-info
 bundle update mimemagic

并尝试捆绑您的 gem 文件