从 capistrano 运行远程 rake 任务，cap deploy bash: -c: line 1: syntax error: unexpected end of file答案

【问题标题】：Run remote rake task from capistrano, cap deploy bash: -c: line 1: syntax error: unexpected end of file从 capistrano 运行远程 rake 任务，cap deploy bash: -c: line 1: syntax error: unexpected end of file
【发布时间】：2012-03-13 22:45:10
【问题描述】：

我在这个话题中关注了@Coward 的回答：How do I run a rake task from Capistrano? 在我的deploy.rb 中添加自定义任务rake:invoke 以便能够远程调用rake 任务。

它本身就可以完美运行，但是当我的cap deploy 处理正在执行assets:precompile 时出现以下错误

[mydomain.com] rvm_path=/usr/local/rvm /usr/local/rvm/bin/rvm-shell '1.9.2@ziya' -c 'cd /var/deploy/ziya/releases/20120223100338 && #<Capistrano::Configuration::Namespaces::Namespace:0x007ff2b4a4bad8> RAILS_ENV=staging RAILS_GROUPS=assets assets:precompile'
 ** [out :: my domain.com] bash: -c: line 1: syntax error: unexpected end of file
    command finished in 1265ms

这就像某种注入的东西，但我就是无法找出我的 deploy.rb 中出了什么问题

deploy.rb：

$:.unshift(File.expand_path('./lib', ENV['rvm_path'])) # Add RVM's lib directory to the load path.
require "rvm/capistrano"                  # Load RVM's capistrano plugin.
set :rvm_ruby_string, '1.9.2@ziya'
set :use_sudo, true

require "bundler/capistrano"

set :stages, %w(staging production)
set :default_stage, "production"
require 'capistrano/ext/multistage'

set :application, "my application"

# ssh to the deploy server
default_run_options[:pty] = true

# setup scm:
set :repository,  "mygiturl"
set :deploy_via, :remote_cache
set :scm_username, "myusernmae"
set :scm, :git
set :scm_verbose, "true"
set :branch, "master"
ssh_options[:forward_agent] = true

set(:releases_path)     { File.join(deploy_to, version_dir) }
set(:shared_path)       { File.join(deploy_to, shared_dir) }
set(:current_path)      { File.join(deploy_to, current_dir) }
set(:release_path)      { File.join(releases_path, release_name) }

set :deploy_to, "/var/deploy/#{application}"

# If you are using Passenger mod_rails uncomment this:
namespace :deploy do
  task :start do ; end
  task :stop do ; end
  task :restart, :roles => :app, :except => { :no_release => true } do
    run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}"
  end

  task :bootstrap do
    run "cd #{release_path}; rake bootstrap:all RAILS_ENV=#{rails_env}"
  end

  task :import_all do
    run "cd #{release_path}; rake import:pages RAILS_ENV=#{rails_env}"
    run "cd #{release_path}; rake import:legacy_all RAILS_ENV=#{rails_env}"
  end  

  task :import_pages do
    run "cd #{release_path}; rake import:pages RAILS_ENV=#{rails_env}"
  end
end

namespace :rake do  
  desc "Run a task on a remote server."  
  # run like: cap staging rake:invoke task=a_certain_task  
  task :invoke do  
    run("cd #{deploy_to}/current; /usr/bin/env rake #{ENV['task']} RAILS_ENV=#{rails_env}")  
  end  
end

但是如果我将task :invoke 移动到namespace :deploy，删除namespace :rake，那么一切正常，这太令人困惑了..

【问题讨论】：

太棒了！救了我的命！谢谢！ =)

标签： ruby-on-rails-3 rake capistrano

【解决方案1】：

自从 Capistrano 在其源代码 declare rake as internal variable 中发生这种情况后，you can override which command is used as rake command line using a set :rake in your deploy file.

但是，由于 capistrano 的内部结构，当您声明 rake 命名空间时，它将优先于声明的 rake 变量。因此，当 capistrano 执行其配方以预编译资产时，它 builds the required command line rake 变量而不是返回 "rake" 字符串返回您声明的命名空间转换为字符串。您可以在构建的命令行的这一部分中看到它：

 ... && #<Capistrano::Configuration::Namespaces::Namespace:0x007ff2b4a4bad8> RAILS_ENV=staging RAILS_GROUPS=assets assets:precompile'

这显然会导致 shell 语法错误，这就是为什么更改命名空间可以解决您的问题的原因。

【讨论】：