如何在VSCode的Rails调试配置launch.json中添加环境变量切换运行环境

Rails启动时会优先读取RAILS_ENV环境变量确定运行环境，你只需要修改launch.json里的对应配置即可，有两种常用实现方式：

方式1：通过env字段指定环境变量 #

在你现有的配置的env对象中新增RAILS_ENV字段，值设为你需要的环境（test/qa/production等均可）：

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Rails server",
            "type": "Ruby",
            "request": "launch",
            "program": "${workspaceRoot}/bin/rails",
            "args": [
                "server"
            ],
            "showDebuggerOutput": true,
            "env": {
                "PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout/bin:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global/bin:/Users/giri.shankar/.rvm/rubies/ruby-2.6.3/bin:/Users/giri.shankar/.rvm/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin",
                "GEM_HOME": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout",
                "GEM_PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global",
                "RUBY_VERSION": "ruby-2.6.3",
                "RAILS_ENV": "test"
            }
        }
    ]
}

方式2：通过rails server启动参数指定 #

在args数组中添加-e参数指定运行环境：

"args": [
    "server",
    "-e",
    "qa"
]

多环境快速切换配置 #

如果需要频繁切换不同环境调试，可以在configurations数组中添加多个配置项，每个对应不同环境，启动调试时直接在VSCode的调试下拉框选择对应环境即可，示例：

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Rails server [开发环境]",
            "type": "Ruby",
            "request": "launch",
            "program": "${workspaceRoot}/bin/rails",
            "args": ["server"],
            "showDebuggerOutput": true,
            "env": {
                "PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout/bin:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global/bin:/Users/giri.shankar/.rvm/rubies/ruby-2.6.3/bin:/Users/giri.shankar/.rvm/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin",
                "GEM_HOME": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout",
                "GEM_PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global",
                "RUBY_VERSION": "ruby-2.6.3",
                "RAILS_ENV": "development"
            }
        },
        {
            "name": "Rails server [测试环境]",
            "type": "Ruby",
            "request": "launch",
            "program": "${workspaceRoot}/bin/rails",
            "args": ["server"],
            "showDebuggerOutput": true,
            "env": {
                "PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout/bin:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global/bin:/Users/giri.shankar/.rvm/rubies/ruby-2.6.3/bin:/Users/giri.shankar/.rvm/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin",
                "GEM_HOME": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout",
                "GEM_PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global",
                "RUBY_VERSION": "ruby-2.6.3",
                "RAILS_ENV": "test"
            }
        },
        {
            "name": "Rails server [QA环境]",
            "type": "Ruby",
            "request": "launch",
            "program": "${workspaceRoot}/bin/rails",
            "args": ["server"],
            "showDebuggerOutput": true,
            "env": {
                "PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout/bin:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global/bin:/Users/giri.shankar/.rvm/rubies/ruby-2.6.3/bin:/Users/giri.shankar/.rvm/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin",
                "GEM_HOME": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout",
                "GEM_PATH": "/Users/giri.shankar/.rvm/gems/ruby-2.6.3@codeforkout:/Users/giri.shankar/.rvm/gems/ruby-2.6.3@global",
                "RUBY_VERSION": "ruby-2.6.3",
                "RAILS_ENV": "qa"
            }
        }
    ]
}

内容的提问来源于stack exchange，提问作者Giri