feat: add plugin - cache control (#810)

plugins/wasm-go/extensions/cache-control/main.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/tidwall/gjson"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func main() {
+	wrapper.SetCtx(
+		"cache-control",
+		wrapper.ParseConfigBy(parseConfig),
+		wrapper.ProcessRequestHeadersBy(onHttpRequestHeaders),
+		wrapper.ProcessResponseHeadersBy(onHttpResponseHeaders),
+	)
+}
+
+type CacheControlConfig struct {
+	suffix  []string
+	expires string
+}
+
+func parseConfig(json gjson.Result, config *CacheControlConfig, log wrapper.Log) error {
+	suffix := json.Get("suffix").String()
+	if suffix != "" {
+		parts := strings.Split(suffix, "|")
+		config.suffix = parts
+	}
+
+	config.expires = json.Get("expires").String()
+
+	log.Infof("suffix: %q, expires: %s", config.suffix, config.expires)
+	return nil
+}
+
+func onHttpRequestHeaders(ctx wrapper.HttpContext, config CacheControlConfig, log wrapper.Log) types.Action {
+	path := ctx.Path()
+	if strings.Contains(path, "?") {
+		path = strings.Split(path, "?")[0]
+	}
+	ctx.SetContext("path", path)
+	log.Debugf("path: %s", path)
+
+	return types.ActionContinue
+}
+
+func onHttpResponseHeaders(ctx wrapper.HttpContext, config CacheControlConfig, log wrapper.Log) types.Action {
+	hit := false
+	if len(config.suffix) == 0 {
+		hit = true
+	} else {
+		path, ok := ctx.GetContext("path").(string)
+		if !ok {
+			log.Error("failed to get request path")
+			return types.ActionContinue
+		}
+
+		for _, part := range config.suffix {
+			if strings.HasSuffix(path, "."+part) {
+				hit = true
+				break
+			}
+		}
+	}
+	if hit {
+		if config.expires == "max" {
+			proxywasm.AddHttpResponseHeader("Expires", "Thu, 31 Dec 2037 23:55:55 GMT")
+			proxywasm.AddHttpResponseHeader("Cache-Control", "maxAge=315360000")
+		} else if config.expires == "epoch" {
+			proxywasm.AddHttpResponseHeader("Expires", "Thu, 01 Jan 1970 00:00:01 GMT")
+			proxywasm.AddHttpResponseHeader("Cache-Control", "no-cache")
+		} else {
+			maxAge, _ := strconv.ParseInt(config.expires, 10, 64)
+			currentTime := time.Now()
+			expireTime := currentTime.Add(time.Duration(maxAge) * time.Second)
+			proxywasm.AddHttpResponseHeader("Expires", expireTime.UTC().Format(http.TimeFormat))
+			proxywasm.AddHttpResponseHeader("Cache-Control", "maxAge="+strconv.FormatInt(maxAge, 10))
+		}
+	}
+	return types.ActionContinue
+}