我正在使用 Capistrano 将 Ruby on Rails 应用程序部署到 Linode VPS。我使用 Unicorn 作为应用程序服务器，使用 Nginx 作为代理。我的问题是，由于明显的权限问题，我无法启动 Unicorn，但我很难找到它。

Unicorn 开始使用这个 Capistrano 任务:

task :start, :roles => :app, :except => { :no_release => true } do
    run <<-CMD
      cd #{current_path} && #{unicorn_bin} -c #{unicorn_config} -E #{rails_env} -D
    CMD
end

我回来了，ArgumentError 指出 pid 文件的路径不可写。

cap unicorn:start                                                                           master [d4447d3] modified
  * executing `unicorn:start'
  * executing "cd /home/deploy/apps/gogy/current && /home/deploy/apps/gogy/current/bin/unicorn -c /home/deploy/apps/gogy/shared/config/unicorn.rb -E production -D"
    servers: ["66.228.52.4"]
    [66.228.52.4] executing command
 ** [out :: 66.228.52.4] /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/configurator.rb:88:in `reload':
 ** [out :: 66.228.52.4] directory for pid=/home/deploy/apps/shared/pids/unicorn.pid not writable (ArgumentError)
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/configurator.rb:84:in `each'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/configurator.rb:84:in `reload'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/configurator.rb:65:in `initialize'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/http_server.rb:102:in `new'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/lib/unicorn/http_server.rb:102:in `initialize'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/bin/unicorn:121:in `new'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/shared/bundle/ruby/1.8/gems/unicorn-4.1.1/bin/unicorn:121
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/current/bin/unicorn:16:in `load'
 ** [out :: 66.228.52.4] from /home/deploy/apps/gogy/current/bin/unicorn:16
 ** [out :: 66.228.52.4] master failed to start, check stderr log for details
    command finished in 1032ms
failed: "rvm_path=/usr/local/rvm /usr/local/rvm/bin/rvm-shell 'default' -c 'cd /home/deploy/apps/gogy/current && /home/deploy/apps/gogy/current/bin/unicorn -c /home/deploy/apps/gogy/shared/config/unicorn.rb -E production -D'" on 66.228.52.4

最后，这是我的 unicorn 配置文件​​(unicorn.rb)的相关部分

# Ensure that we're running in the production environment
rails_env = ENV['RAILS_ENV'] || 'production'

# User to run under
user 'deploy', 'deploy'

# We will spawn off two worker processes and one master process
worker_processes 2

# set the default working directory
working_directory "/home/deploy/apps/gogy/current"

# This loads the application in the master process before forking
# worker processes
# Read more about it here:
# http://unicorn.bogomips.org/Unicorn/Configurator.html
preload_app true

timeout 30

# This is where we specify the socket.
# We will point the upstream Nginx module to this socket later on
listen "/home/deploy/apps/shared/sockets/unicorn.sock", :backlog => 64

pid "/home/deploy/apps/shared/pids/unicorn.pid"

# Set the path of the log files 
stderr_path "/home/deploy/apps/gogy/current/log/unicorn.stderr.log"
stdout_path "/home/deploy/apps/gogy/current/log/unicorn.stdout.log"

我在“部署”用户和组下使用 Capistrano 进行部署，这也是 Unicorn 应该在其下运行的。

有人知道为什么 Unicorn 不能写出 pid 文件吗？任何帮助将不胜感激!!!

• 迈克

最佳答案

其实报错信息已经告诉你原因了:

directory for pid=/home/deploy/apps/shared/pids/unicorn.pid not writable

那么，目录/home/deploy/apps/shared/pids 是否存在？如果没有，您应该调用 mkdir 来创建它。

关于ruby - unicorn 无法写入pid文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8706088/