rails mysql mongoid carrierware gridfs 实现图片上传功能

1.安装

Git: git的安装

MongoDB: MongoDB安装

Nginx: Nginx安装

注: 官方的nginx没有nginx-gridfs功能，需要手动编译进去

安装步骤:

[bash]

cd /tmp

git clone https://github.com/mdirolf/nginx-gridfs
cd nginx-gridfs/

git submodule init

git submodule update

#在 gcc 版本 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC) 上编译时，可能会遇到问题。可以在configure时加上

./configure –add-module=/path/to/nginx-gridfs/source/ –with-cc-opt=-Wno-missing-field-initializers

make && make install

#编辑nginx配置文件

vim /usr/local/nginx/conf/nginx.conf

#注: gridfs 指路由名

location /gridfs/ {

gridfs my_app

root_collection=pics

field=_id

type=int

user=foo

pass=bar;

mongo 127.0.0.1:27017;

}

[/bash]

参考: https://github.com/mdirolf/nginx-gridfs http://serverfault.com/questions/345516/compiling-nginx-with-nginx-gridfs-getting-mongo-c-driver-errors-during-make

二.rails配置

1,搭建rails环境 -> rvm 参考：rails环境搭建

[bash]

vim Gemfile

source ‘http://rubygems.org’

gem ‘rails’

gem ‘mysql2′

gem ‘carrierwave’

gem ‘mini_magick’

gem ‘mongo’

gem ‘bson’

gem ‘bson_ext’

bundle install

[/bash]

2,创建一个rails项目

[bash]

rails new product –database=mysql

rails g scaffold photo name:string image:string #image存储图片名

[/bash]

3,通过generator生成uploader 文件在app/uploader/base_uploader.rb

[bash]

rails g uploader base

#以上创建的父类文件，可以在app/uploader下创建子类文件用于不同的图片上传需要

#修改base_uploader.rb文件并加入MiniMagic,用来对图片进行处理，改变大小等。

# encoding: utf-8

class BaseUploader < CarrierWave::Uploader::Base

include CarrierWave::MiniMagick

storage :grid_fs

end

vim app/uploaders/photo_uploader.rb

# encoding: utf-8

class PhotoUploader < BaseUploader

process :resize_to_limit => [800, 800]

version :thumb do

process :resize_to_limit => [30, 30]

end

end

[/bash]

4, 在model中 mount uploader到image 字段中

[bash]

class Photo < ActiveRecord::Base

attr_accessible :image, :name

mount_uploader :image, PhotoUploader

end

[/bash]

5.在config/initializers/下创建文件carrierwave.rb配置mongodb

[bash]

vim config/initializers/carrierwave.rb

CarrierWave.configure do |config|

config.grid_fs_database = ‘photos’ #数据库名

config.grid_fs_host = ‘localhost’ #mongodb地址

config.grid_fs_access_url = "/uploader" #好像是访问时图片url的前缀

end

[/bash]

6.html模板部分

[bash]

#form

<div class="field">

<%= f.label :image %><br />

<%= f.file_field :image %>

</div>

#index

<%= image_tag photo.image %>

<%= image_tag photo.image_url(:thumb) %>

[/bash]

7. 启动部分

如果是在develop模式下,需要配置路由已经创建controller文件

[bash]

vim app/controller/gridfs_controller.rb

class GridfsController < ActionController::Metal

def serve

gridfs_path = env["PATH_INFO"].gsub("/upload/", "")

begin

gridfs_file = Mongo::GridFileSystem.new(Mongo::DB.new(‘photos’, Mongo::Connection.new(‘localhost’))).open(gridfs_path, ‘r’)

self.response_body = gridfs_file.read

self.content_type = gridfs_file.content_type

rescue Exception => e

self.status = :file_not_found

self.content_type = ‘text/plain’

self.response_body = ”

raise e

end

end

end

vim config/routes.rb

if Rails.env.development?

match "/upload/*path" => "gridfs#serve"

end

[/bash]

8.配置nginx

[bash]

location /images/ {

gridfs photos root_collection=fs field=filename type=string;

mongo 127.0.0.1:27017;

}

[/bash]

9. 安装 nginx-gridfs 模块

注意事项： 如果需要使用nginx直接读取mongo gridfs, 需要重新编辑nginx 安装nginx-gridfs模块

官方的nginx没有nginx-gridfs功能，因此需要手动编译进去。

安装步骤见项目的github主页： https://github.com/mdirolf/nginx-gridfs
遇到的问题及解决方法:

[bash]

# 在 gcc 版本 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC) 上编译时，可能会遇到问题。可以在configure时加上

–with-cc-opt=-Wno-missing-field-initializers

# 选项试试。（ 见 http://serverfault.com/questions/345516/compiling-nginx-with-nginx-gridfs-getting-mongo-c-driver-errors-during-make ）

# 当make是出现错误

#错误： 变量‘chunksize’被设定但未被使用 [-Werror=unused-but-set-variable]

#cc1: all warnings being treated as errors

#去掉objs/makefile中 -Werror这样一段，重新make就ok了

[/bash]