feat: wasm support opa (Open Policy Agent) (#760)

plugins/wasm-go/extensions/opa/config.go

@@ -0,0 +1,82 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/tidwall/gjson"
+)
+
+type OpaConfig struct {
+	policy  string
+	timeout uint32
+
+	client wrapper.HttpClient
+}
+
+func Client(json gjson.Result) (wrapper.HttpClient, error) {
+	serviceSource := strings.TrimSpace(json.Get("serviceSource").String())
+	serviceName := strings.TrimSpace(json.Get("serviceName").String())
+	servicePort := json.Get("servicePort").Int()
+
+	host := strings.TrimSpace(json.Get("host").String())
+	if host == "" {
+		if serviceName == "" || servicePort == 0 {
+			return nil, errors.New("invalid service config")
+		}
+	}
+
+	var namespace string
+	if serviceSource == "k8s" || serviceSource == "nacos" {
+		if namespace = strings.TrimSpace(json.Get("namespace").String()); namespace == "" {
+			return nil, errors.New("namespace not allow empty")
+		}
+	}
+
+	switch serviceSource {
+	case "k8s":
+		return wrapper.NewClusterClient(wrapper.K8sCluster{
+			ServiceName: serviceName,
+			Namespace:   namespace,
+			Port:        servicePort,
+		}), nil
+	case "nacos":
+		return wrapper.NewClusterClient(wrapper.NacosCluster{
+			ServiceName: serviceName,
+			NamespaceID: namespace,
+			Port:        servicePort,
+		}), nil
+	case "ip":
+		return wrapper.NewClusterClient(wrapper.StaticIpCluster{
+			ServiceName: serviceName,
+			Host:        host,
+			Port:        servicePort,
+		}), nil
+	case "dns":
+		return wrapper.NewClusterClient(wrapper.DnsCluster{
+			ServiceName: serviceName,
+			Port:        servicePort,
+			Domain:      json.Get("domain").String(),
+		}), nil
+	case "route":
+		return wrapper.NewClusterClient(wrapper.RouteCluster{
+			Host: host,
+		}), nil
+	}
+	return nil, errors.New("unknown service source: " + serviceSource)
+}