1. 安装fresh工具

Fresh是一个命令行工具，每次更新代码都能够自动重新加载并执行，这在开发过程中非常便利的，省去了每次手动重新编译的麻烦。

PS D:\devops\go\src\github.com\lamxops\gogin> go install github.com/pilu/fresh@latest
go: downloading github.com/pilu/fresh v0.0.0-20190826141211-0fa698148017
go: finding module for package github.com/pilu/config
go: finding module for package github.com/howeyc/fsnotify
go: finding module for package github.com/mattn/go-colorable
go: downloading github.com/mattn/go-colorable v0.1.13
go: downloading github.com/pilu/config v0.0.0-20131214182432-3eb99e6c0b9a
go: downloading github.com/howeyc/fsnotify v0.9.0
go: found github.com/howeyc/fsnotify in github.com/howeyc/fsnotify v0.9.0
go: found github.com/mattn/go-colorable in github.com/mattn/go-colorable v0.1.13
go: found github.com/pilu/config in github.com/pilu/config v0.0.0-20131214182432-3eb99e6c0b9a

2. 使用fresh

在gin项目目录下执行fresh命令即可，替代原来的go run命令。

PS D:\devops\go\src\github.com\lamxops\gogin> fresh
15:0:56 runner      | InitFolders
15:0:56 runner      | mkdir ./tmp
15:0:56 watcher     | Watching .
15:0:56 main        | Waiting (loop 1)...
15:0:56 main        | receiving first event /
15:0:56 main        | sleeping for 600 milliseconds
15:0:57 main        | flushing events
15:0:57 main        | Started! (5 Goroutines)
15:0:57 main        | remove tmp\runner-build-errors.log: The system cannot find the file specified.
15:0:57 build       | Building...
15:0:58 runner      | Running...
15:0:59 main        | --------------------
15:0:59 main        | Waiting (loop 2)...
15:0:59 app         | [GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.

15:0:59 app         | [GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)

[GIN-debug] GET    /ping                     --> main.main.func1 (3 handlers)
[GIN-debug] GET    /hello                    --> main.main.func2 (3 handlers)
[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.
[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default
[GIN-debug] Listening and serving HTTP on :8080
15:1:10 app         | [GIN] 2022/11/28 - 15:01:10 | 200 |       715.2µs |       127.0.0.1 | GET      "/hello"
15:1:10 app         | [GIN] 2022/11/28 - 15:01:10 | 404 |            0s |       127.0.0.1 | GET      "/favicon.ico"

当代码文件发生变更时，fresh会检测到，并自动构建重启gin项目：

15:1:14 watcher     | sending event ".\\example.go": MODIFY
15:1:14 main        | receiving first event ".\\example.go": MODIFY
15:1:14 main        | sleeping for 600 milliseconds
15:1:14 watcher     | sending event ".\\example.go": MODIFY
15:1:14 main        | flushing events
15:1:14 main        | receiving event ".\\example.go": MODIFY
15:1:14 main        | Started! (8 Goroutines)
15:1:14 main        | remove tmp\runner-build-errors.log: The system cannot find the file specified.
15:1:14 build       | Building...
15:1:16 runner      | Running...
15:1:16 runner      | Killing PID 21488
15:1:16 main        | --------------------
15:1:16 main        | Waiting (loop 3)...
15:1:16 app         | [GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.

15:1:16 app         | [GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)

[GIN-debug] GET    /ping                     --> main.main.func1 (3 handlers)
[GIN-debug] GET    /hello                    --> main.main.func2 (3 handlers)
[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.
[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default
[GIN-debug] Listening and serving HTTP on :8080
15:1:17 app         | [GIN] 2022/11/28 - 15:01:17 | 200 |            0s |       127.0.0.1 | GET      "/hello"