air + viper + gin

默认情况下，air 主要监视 Go 源文件的变化来触发重启。如果你希望在修改配置文件（如 config.yaml）时也能触发重启，你需要在 air 的配置文件中指定要监视的文件类型。

以下是如何配置 air 以监视配置文件变化的步骤：

1. 修改 .air.toml 配置文件

在你的 .air.toml 文件中，确保 include_ext 包含配置文件的扩展名（如 yaml）。示例如下：

[build]
  bin = "tmp/main" # Binary output path
  cmd = "go build -o ./tmp/main" # Build command
  full_bin = "APP_ENV=dev APP_USER=air ./tmp/main" # Full binary run command
  include_ext = ["go", "tpl", "tmpl", "html", "yaml", "yml"] # File extensions to watch
  exclude_dir = ["assets", "tmp", "logs"] # Directories to ignore
  exclude_file = ["air.conf"] # Files to ignore
  follow_symlink = true # Follow symlinks
  kill_delay = 1000 # Delay before killing the old process (ms)
  delay = 1000 # Delay before starting new process (ms)
  grace_time = 500 # Grace time for old process to shutdown (ms)
  grace_time_slack = 0 # Additional grace time for old process to shutdown (ms)
  cmd_args = ["-some_arg=some_value"] # Arguments for the build command
  run_args = ["-some_arg=some_value"] # Arguments for the run command
  build_args = ["-a", "-v"] # Arguments for the build command

[log]
  color = true # Use colored output
  time = true # Show time in log
  level = "info" # Log level (debug, info, warn, error, fatal)

[watch]
  exclude = ["assets", "tmp", "logs"] # Directories to ignore
  include = ["*.go", "*.tpl", "*.tmpl", "*.html", "*.yaml", "*.yml"] # File patterns to watch
  follow_symlink = true # Follow symlinks
  delay = 1000 # Delay before rebuilding (ms)

2. 运行 air

在项目根目录下运行 air：

air

3. 触发重启

现在，当你修改 config.yaml 文件时，air 也会监视到这些变化并自动重启你的应用。

示例

假设你有以下配置文件 config.yaml：

server:
  port: 8080

当你修改 config.yaml 文件中的端口号，例如：

server:
  port: 9090

air 会自动检测到这个变化并重启你的应用，使得新配置生效。

完整示例

以下是一个完整的项目结构和代码示例：

your_project_name/
├── .air.toml
├── config.yaml
├── go.mod
└── main.go

.air.toml

[build]
  bin = "tmp/main"
  cmd = "go build -o ./tmp/main"
  full_bin = "APP_ENV=dev APP_USER=air ./tmp/main"
  include_ext = ["go", "tpl", "tmpl", "html", "yaml", "yml"]
  exclude_dir = ["assets", "tmp", "logs"]
  exclude_file = ["air.conf"]
  follow_symlink = true
  kill_delay = 1000
  delay = 1000
  grace_time = 500
  grace_time_slack = 0
  cmd_args = ["-some_arg=some_value"]
  run_args = ["-some_arg=some_value"]
  build_args = ["-a", "-v"]

[log]
  color = true
  time = true
  level = "info"

[watch]
  exclude = ["assets", "tmp", "logs"]
  include = ["*.go", "*.tpl", "*.tmpl", "*.html", "*.yaml", "*.yml"]
  follow_symlink = true
  delay = 1000

config.yaml

server:
  port: 8080

main.go

package main

import (
    "fmt"
    "log"

    "github.com/gin-gonic/gin"
    "github.com/spf13/viper"
)

func initConfig() {
    viper.SetConfigName("config")
    viper.SetConfigType("yaml")
    viper.AddConfigPath(".")

    if err := viper.ReadInConfig(); err != nil {
        log.Fatalf("Error reading config file, %s", err)
    }
}

func main() {
    initConfig()

    r := gin.Default()
    r.GET("/", func(c *gin.Context) {
        c.String(200, "Hello, World!")
    })

    port := viper.GetString("server.port")
    if port == "" {
        port = "8080"
    }
    r.Run(fmt.Sprintf(":%s", port))
}

通过以上配置和代码，当你修改 config.yaml 文件时，air 会自动重启你的应用，使得配置更改生效。