# [Rails4]安裝rails 4.2.8　 ###### tags: `Rails4` https://progressbar.tw/notes/RubyOnRails/24 ### 安裝curl ```c! sudo apt-get install curl libcurl4-openssl-dev ``` ### 安裝nodejs https://stackoverflow.com/questions/7092107/rails-could-not-find-a-javascript-runtime ```c! sudo apt-get install nodejs ``` ### 安裝rvm https://rvm.io/ ```c! $ sudo apt install gnupg2 $ sudo apt install curl $ \curl -sSL https://get.rvm.io | bash -s stable --rails ``` 安裝完後重開terminal, 輸入以下指令: ```c! $ rvm -v ``` 若有看到版本號表示rvm安裝成功 >ubuntu需先按照以下連結對terminal做設定: https://rvm.io/integration/gnome-terminal ### 切換ruby版本 切換ruby版本至2.2.6: ```c! $ rvm --default use 2.2.6 ``` 若提示未安裝,則需先安裝該版本的ruby: ```c! $ rvm install "ruby-2.2.6" ``` <br> ### 安裝rails 4.2.8 >若已有安裝新版rails, >請先用以下指令移除: ```c! $ gem uninstall rails ``` https://github.com/rubygems/rubygems/issues/2534 在上述網址有提到以下內容: ``` RubyGems 3.0.0 is only installable on Ruby >= 2.3 For 2.2 & 2.2.10, try - gem install "rubygems-update:<3.0.0" --no-document - update_rubygems At present, RubyGems does not correctly handle Ruby version constraints. ``` 所以就照做: ```terminal $ gem install "rubygems-update:<3.0.0" --no-document ``` ```terminal $ update_rubygems ``` (2020/01/01更新) https://stackoverflow.com/questions/18290080/change-rails-version-used-by-rvm/18290486 根據此連結教學,可以安裝不同版本的rails並切換 https://sites.google.com/site/zhoubx/computer/ubuntu-16-04-2-apache-2-4-18-passenger-ruby-2-4-1-rails-5-1-1-postgresql 上述連結提到可加上--default參數 rails與ruby版本對照表: https://www.fastruby.io/blog/ruby/rails/versions/compatibility-table.html 現在假設要在ruby2.2.6的環境下安裝rails4.2.8: ### 新增@rails4變數方便以後切換 ```c! $ rvm use 2.2.6 $ rvm use @rails4 --create ``` ### 安裝舊版nokogiri(1.9.1) ```c! gem install nokogiri -v 1.9.1 ``` ### 安裝舊版sprockets(3.7.2) ```c! gem install sprockets -v 3.7.2 ``` ### 開始安裝rails 4.2.8 ```c! gem install rails -v 4.2.8 --no-ri --no-rdoc ``` >若單純使用gem install rails -v 4.2.8, >則可能會卡在ri的安裝 2020/3/6更新:使用ubuntu 18.04 https://stackoverflow.com/questions/57475842/what-to-use-instead-of-no-ri-for-gem-install ```c! gem install rails -v 4.2.8 -N ``` ### 切換至@rails4 ```c! $ rvm use 2.2.6@rails4 --default $ ruby -v #-->ruby 2.2.6p396 (2016-11-15 revision 56800) [x86_64-linux] $ rails -v #-->Rails 4.2.8 ``` ### 安裝postgresql & pgadmin4 https://blog.gtwang.org/linux/how-to-install-and-use-postgresql-ubuntu-18-04/ #### problem shooting ##### pg gem無法安裝 https://stackoverflow.com/questions/3116015/how-to-install-postgresqls-pg-gem-on-ubuntu ```c! $ sudo apt-get install libpq-dev ``` ##### 其他 [[Postgresql]解決Fatal: role “username” does not exist 錯誤](https://hackmd.io/p24HhyiqR--MvsFXguX2Bw) [[Rails4][err][psql]fe_sendauth: no password supplied](https://hackmd.io/Gw6E-KeeSOWTNI1SJxgasQ) ### 新增專案 https://stackoverflow.com/questions/48911869/add-gem-pg-to-your-gemfile-and-ensure-its-version-is-at-the-minimum-required ```c! rails new app-name -d postgresql ``` >-d參數用於指定要使用的資料庫