proxy_factory.go

package shadowproxy

import (
	"regexp"
	"strings"

	"github.com/luraproject/lura/v2/config"
	"github.com/luraproject/lura/v2/encoding"
	"github.com/luraproject/lura/v2/proxy"
	"golang.org/x/text/cases"
	"golang.org/x/text/language"
)

func ProxyFactory(pf proxy.Factory) proxy.FactoryFunc {
	return func(cfg *config.EndpointConfig) (proxy.Proxy, error) {
		next, err := pf.New(cfg)
		if err != nil {
			panic(err)
		}
		prxCfg, ok := configGetter(cfg)
		if !ok {
			return next, nil
		}
		shadowProxy, err := pf.New(shadowConfig(*cfg, *prxCfg))
		if err != nil {
			panic(err)
		}
		return proxy.ShadowMiddlewareWithTimeout(prxCfg.Timeout, next, shadowProxy), nil
	}
}

func shadowConfig(cfg config.EndpointConfig, prxCfg ProxyConfig) *config.EndpointConfig { // nolint
	urlPattern, urlKeys := parseURLPattern(prxCfg.URLPattern)
	cfg.Backend = []*config.Backend{{
		Host:                     prxCfg.Host,
		Method:                   prxCfg.Method,
		URLPattern:               urlPattern,
		HostSanitizationDisabled: prxCfg.HostSanitizationDisabled,
		URLKeys:                  urlKeys,
		Encoding:                 encoding.NOOP,
		Timeout:                  prxCfg.Timeout,
	}}
	return &cfg
}

func parseURLPattern(urlPattern string) (string, []string) { // nolint
	re := regexp.MustCompile(`/\{([a-zA-Z\-_0-9]+)\}`)
	urlKeys := []string{}
	if matches := re.FindAllStringSubmatch(urlPattern, -1); matches != nil {
		title := cases.Title(language.Und)
		for _, v := range matches {
			key := v[1]
			titleKey := title.String(key[:1]) + key[1:]
			urlPattern = strings.ReplaceAll(urlPattern, "{"+key+"}", "{{."+titleKey+"}}")
			urlKeys = append(urlKeys, titleKey)
		}
	}
	return urlPattern, urlKeys
}