ruby-on-rails-3 - Ruby on Rails + PostgreSQL 应用程序无法在 AWS EC2 上启动。错误是 : "cannot load such file -- pg_ext (LoadError)"

Question

我首先安装了所有这些依赖项:

sudo yum install ruby19 ruby19-devel gem rubygems19-devel make gcc postgresql9 postgresql9-devel postgresql9-server

然后我切换到 root 用户并运行

bundle install

然后我收到绿色的成功消息:

Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

但是，当我 cd 到目录并运行时

rails s -p80

我得到了所有这些但它无法启动(我仍然是 root，因为如果我不是 root，绑定(bind)将无法工作到端口 80):

/usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- pg_ext (LoadError)
    from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `block in require'
    from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
    from /usr/local/share/gems/gems/pg-0.14.0/lib/pg.rb:4:in `<top (required)>'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:68:in `require'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:66:in `each'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:66:in `block in require'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:55:in `each'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:55:in `require'
    from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler.rb:128:in `require'
    from /home/user/TransForm/config/application.rb:7:in `<top (required)>'
    from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:53:in `require'
    from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:53:in `block in <top (required)>'
    from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:50:in `tap'
    from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

也许有一种简单的方法可以从一开始就正确部署它，而不是乱搞错误？我需要 PostgreSQL。除了这个 AWS EC2 实例，这个应用程序在任何地方都可以工作，所以我知道我的 Gemfile 是正确的。任何线索都会有所帮助。

Answer 1

打开 irb 并输入 require "pg" 它有效吗？如果没有，则检查 /usr/local/share/gems/gems/pg-0.14.0/lib/ 目录中是否存在 pg_ext。您可以手动安装 postgresql gem，使用

gem install pg

如果这仍然不起作用，请确保您使用的是最新版本的 ruby​​ 和最新版本的 ruby​​gems 使用 gem environment 命令。如果它是旧版本，您可以使用 rvm 安装最新版本