部署Rails应用到AWS Elastic Beanstalk时遇运行报错的求助

AWS新手在将Rails应用部署至Elastic Beanstalk过程中出现服务访问故障，关联的核心日志及问题说明如下：

Nginx错误日志 #

• 日志路径：/var/log/nginx/error.log
• 日志内容：

2021/04/04 14:11:01 [crit] 3132#0: *1 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET / HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com"
2021/04/04 14:11:01 [crit] 3132#0: *1 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET /favicon.ico HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/favicon.ico", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com", referrer: "http://quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com/"
2021/04/04 14:18:14 [crit] 3132#0: *6 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET / HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com"
2021/04/04 14:18:15 [crit] 3132#0: *6 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET /favicon.ico HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/favicon.ico", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com", referrer: "http://quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com/"
2021/04/04 14:51:47 [crit] 3132#0: *11 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET / HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com"
2021/04/04 14:51:47 [crit] 3132#0: *11 connect() to unix:///var/run/puma/my_app.sock failed (2: No such file or directory) while connecting to upstream, client: 137.59.228.225, server: _, request: "GET /favicon.ico HTTP/1.1", upstream: "http://unix:///var/run/puma/my_app.sock:/favicon.ico", host: "quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com", referrer: "http://quinplus-env-1.eba-3w3vyz3h.us-east-2.elasticbeanstalk.com/"

• 日志含义：Nginx反向代理无法连接到Puma应用预设的Unix套接字文件，说明后端应用服务完全没有正常运行。

部署活动日志 #

• 日志路径：/var/log/eb-activity.log
• 日志内容：

Warning: the running version of Bundler (1.16.0) is older than the version that created the lockfile (1.17.3). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
Your Ruby version is 2.5.8, but your Gemfile specified 2.5.1 (Executor::NonZeroExitStatus)

• 日志含义：这是导致Puma服务无法启动的直接根因，部署流程因版本校验不通过被直接中断，根本没有走到启动应用服务的步骤，自然不会生成对应的套接字文件。

对应解决操作 #

• 匹配Ruby运行时版本：要么修改项目Gemfile中的Ruby版本声明，将指定的2.5.1调整为环境实际运行的2.5.8；要么在Elastic Beanstalk环境配置中切换为2.5.1版本的Ruby运行时，和项目声明保持一致。调整后同步更新Gemfile.lock，重新提交代码部署。
• 匹配Bundler版本：通过项目根目录下的.ebextensions配置，在部署流程中自动安装和Gemfile.lock版本匹配的Bundler（1.17.3），避免版本不兼容导致的依赖安装失败。
• 部署完成后校验：确认Puma服务正常启动、/var/run/puma/my_app.sock套接字文件正常生成，即可恢复Nginx的请求转发能力。

内容的提问来源于stack exchange，提问作者Spacehead