英文:
Passing a string to a handler function in Go
问题
我有一个通用的Web服务器，我想在不同的域名/服务器上使用它。
为了设置每个服务器，我只需读取一个包含所有必要信息的JSON配置文件。其中一个配置项是将所有到达端口80的流量重定向到TLS服务。由于我不想将配置对象设为全局变量，我该如何将inputFromConfigFile的内容传递给redirectTLS函数？
以下是一个示例：
func main(){var inputFromConfigFile = "https://www.example.com:443"go func() {if err := http.ListenAndServe(":80", http.HandlerFunc(redirectTLS)); err != nil {log.Fatalf("ListenAndServe error: %v", err)}}()}//将上述字符串传递给此函数：func redirectTLS(w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, "https://www.example.com:443"+r.RequestURI,http.StatusMovedPermanently)}
英文:
I have a generic Webserver which I want to use on different domains / servers.
For setting up each server I simply read a JSON config file with all necessary information. One would be for example the redirect for all traffic which reaches port 80 and forward it to a TLS service. Since I don't want to make the config object global. How can I pass the content from my inputFromConfigFile to the redirectTLS function?
Here is an example:
func main(){var inputFromConfigFile = "https://www.example.com:443"go func() {if err := http.ListenAndServe(":80", http.HandlerFunc(redirectTLS)); err != nil {log.Fatalf("ListenAndServe error: %v", err)}}()}//Pass the above string to this function:func redirectTLS(w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, "https://www.example.com:443"+r.RequestURI,http.StatusMovedPermanently)}
答案1
得分: 3
你可以定义一个自定义的处理程序（可以实现为结构体），只要它符合http.Handler接口。配置可以保存在处理程序中作为结构字段。
type Handler struct {// 配置放在这里}func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {// 处理程序需要执行的任何操作}
示例：https://pkg.go.dev/net/http#example-Handle
英文:
You can define a custom Handler (could be implemented as a struct) as long as it matches the http.Handler interface. The config could be saved inside the Handler as a struct field.
type Handler struct {// config goes here}func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {// anything that handler needs to do here}
答案2
得分: 1
你可以直接在主函数中定义redirectTLS作为内联闭包函数：
var inputFromConfigFile = "https://www.example.com:443"go func() {err := http.ListenAndServe(":80", func(w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, inputFromConfigFile+r.RequestURI, http.StatusMovedPermanently)})if err != nil {log.Fatalf("ListenAndServe error: %v", err)}}()
这段代码的作用是在主函数中定义一个闭包函数redirectTLS，然后使用http.ListenAndServe函数监听端口80，并在接收到请求时进行重定向。重定向的目标地址是从配置文件中获取的inputFromConfigFile加上当前请求的URI。如果监听过程中出现错误，会使用log.Fatalf函数输出错误信息并终止程序的执行。
英文:
You can define redirectTLS as an inline closure function directly in main:
var inputFromConfigFile = "https://www.example.com:443"go func() {err := http.ListenAndServe(":80", func(w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, inputFromConfigFile+r.RequestURI, http.StatusMovedPermanently)})if err != nil {log.Fatalf("ListenAndServe error: %v", err)}}()
答案3
得分: 0
我会将配置对象设为全局变量。
否则，你可以定义一个接受配置作为参数并返回一个闭包函数的函数：
var inputFromConfigFile = "https://www.example.com:443"http.ListenAndServe(":80", createHandler(inputFromConfigFile))// ...func createHandler(config string) http.HandlerFunc {return http.HandlerFunc(func (w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, config+r.RequestURI,http.StatusMovedPermanently)})}
英文:
I would make the config object global.
Otherwise, you can define a function that accepts the config as an argument, and returns a handler function that closes over the configuration object:
var inputFromConfigFile = "https://www.example.com:443"http.ListenAndServe(":80", createHandler(inputFromConfigFile))// ...func createHandler(config string) http.HandlerFunc {return http.HandlerFunc(func (w http.ResponseWriter, r *http.Request) {http.Redirect(w, r, config+r.RequestURI,http.StatusMovedPermanently)})}
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