package middleware import ( "regexp" "github.com/labstack/echo/v4" ) type ( // RewriteConfig defines the config for Rewrite middleware. RewriteConfig struct { // Skipper defines a function to skip middleware. Skipper Skipper // Rules defines the URL path rewrite rules. The values captured in asterisk can be // retrieved by index e.g. $1, $2 and so on. // Example: // "/old": "/new", // "/api/*": "/$1", // "/js/*": "/public/javascripts/$1", // "/users/*/orders/*": "/user/$1/order/$2", // Required. Rules map[string]string `yaml:"rules"` // RegexRules defines the URL path rewrite rules using regexp.Rexexp with captures // Every capture group in the values can be retrieved by index e.g. $1, $2 and so on. // Example: // "^/old/[0.9]+/": "/new", // "^/api/.+?/(.*)": "/v2/$1", RegexRules map[*regexp.Regexp]string `yaml:"-"` } ) var ( // DefaultRewriteConfig is the default Rewrite middleware config. DefaultRewriteConfig = RewriteConfig{ Skipper: DefaultSkipper, } ) // Rewrite returns a Rewrite middleware. // // Rewrite middleware rewrites the URL path based on the provided rules. func Rewrite(rules map[string]string) echo.MiddlewareFunc { c := DefaultRewriteConfig c.Rules = rules return RewriteWithConfig(c) } // RewriteWithConfig returns a Rewrite middleware with config. // See: `Rewrite()`. func RewriteWithConfig(config RewriteConfig) echo.MiddlewareFunc { // Defaults if config.Rules == nil && config.RegexRules == nil { panic("echo: rewrite middleware requires url path rewrite rules or regex rules") } if config.Skipper == nil { config.Skipper = DefaultBodyDumpConfig.Skipper } if config.RegexRules == nil { config.RegexRules = make(map[*regexp.Regexp]string) } for k, v := range rewriteRulesRegex(config.Rules) { config.RegexRules[k] = v } return func(next echo.HandlerFunc) echo.HandlerFunc { return func(c echo.Context) (err error) { if config.Skipper(c) { return next(c) } if err := rewriteURL(config.RegexRules, c.Request()); err != nil { return err } return next(c) } } }