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echo/middleware/middleware.go
Roland Lammel 932976ded6
Support real regex rules for rewrite and proxy middleware (#1767)
Support real regex rules for rewrite and proxy middleware (use non-greedy matching by default)

Co-authored-by: pwli <lipw0755@gmail.com>
2021-02-08 16:58:55 +02:00

65 lines
1.6 KiB
Go

package middleware
import (
"net/http"
"regexp"
"strconv"
"strings"
"github.com/labstack/echo/v4"
)
type (
// Skipper defines a function to skip middleware. Returning true skips processing
// the middleware.
Skipper func(echo.Context) bool
// BeforeFunc defines a function which is executed just before the middleware.
BeforeFunc func(echo.Context)
)
func captureTokens(pattern *regexp.Regexp, input string) *strings.Replacer {
groups := pattern.FindAllStringSubmatch(input, -1)
if groups == nil {
return nil
}
values := groups[0][1:]
replace := make([]string, 2*len(values))
for i, v := range values {
j := 2 * i
replace[j] = "$" + strconv.Itoa(i+1)
replace[j+1] = v
}
return strings.NewReplacer(replace...)
}
func rewriteRulesRegex(rewrite map[string]string) map[*regexp.Regexp]string {
// Initialize
rulesRegex := map[*regexp.Regexp]string{}
for k, v := range rewrite {
k = regexp.QuoteMeta(k)
k = strings.Replace(k, `\*`, "(.*?)", -1)
if strings.HasPrefix(k, `\^`) {
k = strings.Replace(k, `\^`, "^", -1)
}
k = k + "$"
rulesRegex[regexp.MustCompile(k)] = v
}
return rulesRegex
}
func rewritePath(rewriteRegex map[*regexp.Regexp]string, req *http.Request) {
for k, v := range rewriteRegex {
replacerRawPath := captureTokens(k, req.URL.EscapedPath())
if replacerRawPath != nil {
replacerPath := captureTokens(k, req.URL.Path)
req.URL.RawPath, req.URL.Path = replacerRawPath.Replace(v), replacerPath.Replace(v)
}
}
}
// DefaultSkipper returns false which processes the middleware.
func DefaultSkipper(echo.Context) bool {
return false
}