feat: add wasm-rust sdk with say-hello simple extension (#350)

plugins/wasm-rust/extensions/say-hello/envoy.yaml

@@ -0,0 +1,86 @@
+# Copyright (c) 2023 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.
+
+static_resources:
+  listeners:
+    address:
+      socket_address:
+        address: 0.0.0.0
+        port_value: 10000
+    filter_chains:
+      - filters:
+          - name: envoy.filters.network.http_connection_manager
+            typed_config:
+              "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+              stat_prefix: ingress_http
+              codec_type: AUTO
+              route_config:
+                name: local_routes
+                virtual_hosts:
+                  - name: local_service
+                    domains:
+                      - "*"
+                    routes:
+                      - name: lucy
+                        match:
+                          prefix: "/lucy"
+                        direct_response:
+                          status: 200
+                      - name: index
+                        match:
+                          prefix: "/"
+                        direct_response:
+                          status: 200
+              http_filters:
+                - name: envoy.filters.http.wasm
+                  typed_config:
+                    "@type": type.googleapis.com/udpa.type.v1.TypedStruct
+                    type_url: type.googleapis.com/envoy.extensions.filters.http.wasm.v3.Wasm
+                    value:
+                      config:
+                        name: "http_body"
+                        configuration:
+                          "@type": type.googleapis.com/google.protobuf.StringValue
+                          value: |-
+                            {
+                              "name": "Alice",
+                              "_rules_": [
+                                {
+                                  "_match_domain_": [
+                                    "foo"
+                                  ],
+                                  "name": "Foo"
+                                },
+                                {
+                                  "_match_domain_": [
+                                    "bar"
+                                  ],
+                                  "name": "Bar"
+                                },
+                                {
+                                  "_match_route_": [
+                                    "lucy"
+                                  ],
+                                  "name": "Lucy"
+                                }
+                              ]
+                            }
+                        vm_config:
+                          runtime: "envoy.wasm.runtime.v8"
+                          code:
+                            local:
+                              filename: "/etc/envoy/proxy-wasm-plugins/say_hello.wasm"
+                - name: envoy.filters.http.router
+                  typed_config:
+                    "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router