Add cache example (#2232)

2025-02-04 18:21:53 +02:00 · 2021-09-01 11:08:43 +02:00 · 2021-09-01 11:08:43 +02:00 · ed9053ed94
commit ed9053ed94
parent 05a299b76c
9 changed files with 805 additions and 4 deletions
--- a/examples/README.md
+++ b/examples/README.md
@ -5,6 +5,7 @@ This is a repository for go-micro examples. Feel free to contribute.
 ## Contents

 - [broker](broker) - A example of using Broker for Publish and Subscribing.
+- [cache](cache) - Usage of the Cache package to create a cache service.
 - [client](client) - Usage of the Client package to call a service.
 - [config](config) - Using Go Config for dynamic config
 - [event](event) - Using the API Gateway event handler
--- a/examples/cache/README.md
+++ b/examples/cache/README.md
@ -0,0 +1,47 @@
+# Cache
+
+This is an example of a cache service using the [asim/go-micro/cache][1] package.
+
+## Contents
+
+This project was generated using [Gomu][2].
+
+* handler - contains the service handler
+* proto - contains the protocol buffer and generated code
+
+## Usage
+
+Run the `go.micro.srv.cache` service using [Gomu][2].
+
+```bash
+gomu run
+```
+
+You can also run it using plain Go.
+
+```bash
+go run main.go
+```
+
+We'll be using [Gomu][2] to call the service. You can store a new key-value
+pair in the cache.
+
+```bash
+gomu call go.micro.srv.cache Cache.Put '{"key":"test","value":"hello go-micro","duration":"12h"}'
+```
+
+You can get values from the cache.
+
+```bash
+$ gomu call go.micro.srv.cache Cache.Get '{"key":"test"}'
+{"expiration":"2021-09-01 22:42:24.2370591 +0200 CEST","value":"hello go-micro"}
+```
+
+Finally you can delete keys from the cache.
+
+```bash
+gomu call go.micro.srv.cache Cache.Delete '{"key":"test"}'
+```
+
+[1]: https://github.com/asim/go-micro/tree/master/cache
+[2]: https://github.com/asim/go-micro/tree/master/cmd/gomu
--- a/examples/cache/handler/cache.go
+++ b/examples/cache/handler/cache.go
@ -0,0 +1,60 @@
+package handler
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/asim/go-micro/v3/cache"
+	log "github.com/asim/go-micro/v3/logger"
+
+	pb "github.com/asim/go-micro/examples/v3/cache/proto"
+)
+
+type Cache struct {
+	cache cache.Cache
+}
+
+func NewCache(opts ...cache.Option) *Cache {
+	c := cache.NewCache(opts...)
+	return &Cache{c}
+}
+
+func (c *Cache) Get(ctx context.Context, req *pb.GetRequest, rsp *pb.GetResponse) error {
+	log.Infof("Received Cache.Get request: %v", req)
+
+	v, e, err := c.cache.Context(ctx).Get(req.Key)
+	if err != nil {
+		return err
+	}
+
+	rsp.Value = fmt.Sprintf("%v", v)
+	rsp.Expiration = e.String()
+
+	return nil
+}
+
+func (c *Cache) Put(ctx context.Context, req *pb.PutRequest, rsp *pb.PutResponse) error {
+	log.Infof("Received Cache.Put request: %v", req)
+
+	d, err := time.ParseDuration(req.Duration)
+	if err != nil {
+		return err
+	}
+
+	if err := c.cache.Context(ctx).Put(req.Key, req.Value, d); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *Cache) Delete(ctx context.Context, req *pb.DeleteRequest, rsp *pb.DeleteResponse) error {
+	log.Infof("Received Cache.Delete request: %v", req)
+
+	if err := c.cache.Context(ctx).Delete(req.Key); err != nil {
+		return err
+	}
+
+	return nil
+}
--- a/examples/cache/main.go
+++ b/examples/cache/main.go
@ -0,0 +1,31 @@
+package main
+
+import (
+	"github.com/asim/go-micro/examples/v3/cache/handler"
+	pb "github.com/asim/go-micro/examples/v3/cache/proto"
+
+	"github.com/asim/go-micro/v3"
+	log "github.com/asim/go-micro/v3/logger"
+)
+
+var (
+	service = "go.micro.srv.cache"
+	version = "latest"
+)
+
+func main() {
+	// Create service
+	srv := micro.NewService(
+		micro.Name(service),
+		micro.Version(version),
+	)
+	srv.Init()
+
+	// Register handler
+	pb.RegisterCacheHandler(srv.Server(), handler.NewCache())
+
+	// Run service
+	if err := srv.Run(); err != nil {
+		log.Fatal(err)
+	}
+}
--- a/examples/cache/proto/cache.pb.go
+++ b/examples/cache/proto/cache.pb.go
@ -0,0 +1,486 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.26.0
+// 	protoc        v3.6.1
+// source: proto/cache.proto
+
+package cache
+
+import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type GetRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// The key to fetch from the cache.
+	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+}
+
+func (x *GetRequest) Reset() {
+	*x = GetRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetRequest) ProtoMessage() {}
+
+func (x *GetRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use GetRequest.ProtoReflect.Descriptor instead.
+func (*GetRequest) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *GetRequest) GetKey() string {
+	if x != nil {
+		return x.Key
+	}
+	return ""
+}
+
+type GetResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// The value retrieved from the cache.
+	Value string `protobuf:"bytes,1,opt,name=value,proto3" json:"value,omitempty"`
+	// The value's expiration datetime.
+	Expiration string `protobuf:"bytes,2,opt,name=expiration,proto3" json:"expiration,omitempty"`
+}
+
+func (x *GetResponse) Reset() {
+	*x = GetResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[1]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetResponse) ProtoMessage() {}
+
+func (x *GetResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[1]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use GetResponse.ProtoReflect.Descriptor instead.
+func (*GetResponse) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *GetResponse) GetValue() string {
+	if x != nil {
+		return x.Value
+	}
+	return ""
+}
+
+func (x *GetResponse) GetExpiration() string {
+	if x != nil {
+		return x.Expiration
+	}
+	return ""
+}
+
+type PutRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// The key to store in the cache.
+	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+	// The value to store in the cache.
+	Value string `protobuf:"bytes,2,opt,name=value,proto3" json:"value,omitempty"`
+	// The value's time to live. Parsed using time.ParseDuration. 0 means
+	// it doesn't expire.
+	Duration string `protobuf:"bytes,3,opt,name=duration,proto3" json:"duration,omitempty"`
+}
+
+func (x *PutRequest) Reset() {
+	*x = PutRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[2]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *PutRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PutRequest) ProtoMessage() {}
+
+func (x *PutRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[2]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use PutRequest.ProtoReflect.Descriptor instead.
+func (*PutRequest) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{2}
+}
+
+func (x *PutRequest) GetKey() string {
+	if x != nil {
+		return x.Key
+	}
+	return ""
+}
+
+func (x *PutRequest) GetValue() string {
+	if x != nil {
+		return x.Value
+	}
+	return ""
+}
+
+func (x *PutRequest) GetDuration() string {
+	if x != nil {
+		return x.Duration
+	}
+	return ""
+}
+
+type PutResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *PutResponse) Reset() {
+	*x = PutResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[3]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *PutResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PutResponse) ProtoMessage() {}
+
+func (x *PutResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[3]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use PutResponse.ProtoReflect.Descriptor instead.
+func (*PutResponse) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{3}
+}
+
+type DeleteRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// The key to remove from the cache.
+	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+}
+
+func (x *DeleteRequest) Reset() {
+	*x = DeleteRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[4]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *DeleteRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*DeleteRequest) ProtoMessage() {}
+
+func (x *DeleteRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[4]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use DeleteRequest.ProtoReflect.Descriptor instead.
+func (*DeleteRequest) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{4}
+}
+
+func (x *DeleteRequest) GetKey() string {
+	if x != nil {
+		return x.Key
+	}
+	return ""
+}
+
+type DeleteResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *DeleteResponse) Reset() {
+	*x = DeleteResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[5]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *DeleteResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*DeleteResponse) ProtoMessage() {}
+
+func (x *DeleteResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[5]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use DeleteResponse.ProtoReflect.Descriptor instead.
+func (*DeleteResponse) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{5}
+}
+
+var File_proto_cache_proto protoreflect.FileDescriptor
+
+var file_proto_cache_proto_rawDesc = []byte{
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+	0x33,
+}
+
+var (
+	file_proto_cache_proto_rawDescOnce sync.Once
+	file_proto_cache_proto_rawDescData = file_proto_cache_proto_rawDesc
+)
+
+func file_proto_cache_proto_rawDescGZIP() []byte {
+	file_proto_cache_proto_rawDescOnce.Do(func() {
+		file_proto_cache_proto_rawDescData = protoimpl.X.CompressGZIP(file_proto_cache_proto_rawDescData)
+	})
+	return file_proto_cache_proto_rawDescData
+}
+
+var file_proto_cache_proto_msgTypes = make([]protoimpl.MessageInfo, 6)
+var file_proto_cache_proto_goTypes = []interface{}{
+	(*GetRequest)(nil),     // 0: cache.GetRequest
+	(*GetResponse)(nil),    // 1: cache.GetResponse
+	(*PutRequest)(nil),     // 2: cache.PutRequest
+	(*PutResponse)(nil),    // 3: cache.PutResponse
+	(*DeleteRequest)(nil),  // 4: cache.DeleteRequest
+	(*DeleteResponse)(nil), // 5: cache.DeleteResponse
+}
+var file_proto_cache_proto_depIdxs = []int32{
+	0, // 0: cache.Cache.Get:input_type -> cache.GetRequest
+	2, // 1: cache.Cache.Put:input_type -> cache.PutRequest
+	4, // 2: cache.Cache.Delete:input_type -> cache.DeleteRequest
+	1, // 3: cache.Cache.Get:output_type -> cache.GetResponse
+	3, // 4: cache.Cache.Put:output_type -> cache.PutResponse
+	5, // 5: cache.Cache.Delete:output_type -> cache.DeleteResponse
+	3, // [3:6] is the sub-list for method output_type
+	0, // [0:3] is the sub-list for method input_type
+	0, // [0:0] is the sub-list for extension type_name
+	0, // [0:0] is the sub-list for extension extendee
+	0, // [0:0] is the sub-list for field type_name
+}
+
+func init() { file_proto_cache_proto_init() }
+func file_proto_cache_proto_init() {
+	if File_proto_cache_proto != nil {
+		return
+	}
+	if !protoimpl.UnsafeEnabled {
+		file_proto_cache_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetResponse); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*PutRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[3].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*PutResponse); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[4].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*DeleteRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[5].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*DeleteResponse); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_proto_cache_proto_rawDesc,
+			NumEnums:      0,
+			NumMessages:   6,
+			NumExtensions: 0,
+			NumServices:   1,
+		},
+		GoTypes:           file_proto_cache_proto_goTypes,
+		DependencyIndexes: file_proto_cache_proto_depIdxs,
+		MessageInfos:      file_proto_cache_proto_msgTypes,
+	}.Build()
+	File_proto_cache_proto = out.File
+	file_proto_cache_proto_rawDesc = nil
+	file_proto_cache_proto_goTypes = nil
+	file_proto_cache_proto_depIdxs = nil
+}
--- a/examples/cache/proto/cache.pb.micro.go
+++ b/examples/cache/proto/cache.pb.micro.go
@ -0,0 +1,127 @@
+// Code generated by protoc-gen-micro. DO NOT EDIT.
+// source: proto/cache.proto
+
+package cache
+
+import (
+	fmt "fmt"
+	proto "google.golang.org/protobuf/proto"
+	math "math"
+)
+
+import (
+	context "context"
+	api "github.com/asim/go-micro/v3/api"
+	client "github.com/asim/go-micro/v3/client"
+	server "github.com/asim/go-micro/v3/server"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ api.Endpoint
+var _ context.Context
+var _ client.Option
+var _ server.Option
+
+// Api Endpoints for Cache service
+
+func NewCacheEndpoints() []*api.Endpoint {
+	return []*api.Endpoint{}
+}
+
+// Client API for Cache service
+
+type CacheService interface {
+	// Get receives a value and its time to live by key from the cache.
+	Get(ctx context.Context, in *GetRequest, opts ...client.CallOption) (*GetResponse, error)
+	// Put stores a value and its time to live in the cache.
+	Put(ctx context.Context, in *PutRequest, opts ...client.CallOption) (*PutResponse, error)
+	// Delete removes a key from the cache.
+	Delete(ctx context.Context, in *DeleteRequest, opts ...client.CallOption) (*DeleteResponse, error)
+}
+
+type cacheService struct {
+	c    client.Client
+	name string
+}
+
+func NewCacheService(name string, c client.Client) CacheService {
+	return &cacheService{
+		c:    c,
+		name: name,
+	}
+}
+
+func (c *cacheService) Get(ctx context.Context, in *GetRequest, opts ...client.CallOption) (*GetResponse, error) {
+	req := c.c.NewRequest(c.name, "Cache.Get", in)
+	out := new(GetResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cacheService) Put(ctx context.Context, in *PutRequest, opts ...client.CallOption) (*PutResponse, error) {
+	req := c.c.NewRequest(c.name, "Cache.Put", in)
+	out := new(PutResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cacheService) Delete(ctx context.Context, in *DeleteRequest, opts ...client.CallOption) (*DeleteResponse, error) {
+	req := c.c.NewRequest(c.name, "Cache.Delete", in)
+	out := new(DeleteResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for Cache service
+
+type CacheHandler interface {
+	// Get receives a value and its time to live by key from the cache.
+	Get(context.Context, *GetRequest, *GetResponse) error
+	// Put stores a value and its time to live in the cache.
+	Put(context.Context, *PutRequest, *PutResponse) error
+	// Delete removes a key from the cache.
+	Delete(context.Context, *DeleteRequest, *DeleteResponse) error
+}
+
+func RegisterCacheHandler(s server.Server, hdlr CacheHandler, opts ...server.HandlerOption) error {
+	type cache interface {
+		Get(ctx context.Context, in *GetRequest, out *GetResponse) error
+		Put(ctx context.Context, in *PutRequest, out *PutResponse) error
+		Delete(ctx context.Context, in *DeleteRequest, out *DeleteResponse) error
+	}
+	type Cache struct {
+		cache
+	}
+	h := &cacheHandler{hdlr}
+	return s.Handle(s.NewHandler(&Cache{h}, opts...))
+}
+
+type cacheHandler struct {
+	CacheHandler
+}
+
+func (h *cacheHandler) Get(ctx context.Context, in *GetRequest, out *GetResponse) error {
+	return h.CacheHandler.Get(ctx, in, out)
+}
+
+func (h *cacheHandler) Put(ctx context.Context, in *PutRequest, out *PutResponse) error {
+	return h.CacheHandler.Put(ctx, in, out)
+}
+
+func (h *cacheHandler) Delete(ctx context.Context, in *DeleteRequest, out *DeleteResponse) error {
+	return h.CacheHandler.Delete(ctx, in, out)
+}
--- a/examples/cache/proto/cache.proto
+++ b/examples/cache/proto/cache.proto
@ -0,0 +1,46 @@
+syntax = "proto3";
+
+package cache;
+
+option go_package = "./proto;cache";
+
+// Cache offers a cache as a service functionality.
+service Cache {
+    // Get receives a value and its time to live by key from the cache.
+    rpc Get(GetRequest) returns (GetResponse) {}
+    // Put stores a value and its time to live in the cache.
+    rpc Put(PutRequest) returns (PutResponse) {}
+    // Delete removes a key from the cache.
+    rpc Delete(DeleteRequest) returns (DeleteResponse) {}
+}
+
+message GetRequest {
+    // The key to fetch from the cache.
+    string key = 1;
+}
+
+message GetResponse {
+    // The value retrieved from the cache.
+    string value = 1;
+    // The value's expiration datetime.
+    string expiration = 2;
+}
+
+message PutRequest {
+    // The key to store in the cache.
+    string key = 1;
+    // The value to store in the cache.
+    string value = 2;
+    // The value's time to live. Parsed using time.ParseDuration. 0 means
+    // it doesn't expire.
+    string duration = 3;
+}
+
+message PutResponse {}
+
+message DeleteRequest {
+    // The key to remove from the cache.
+    string key = 1;
+}
+
+message DeleteResponse {}
--- a/examples/go.mod
+++ b/examples/go.mod
@ -10,14 +10,15 @@ require (
 	github.com/asim/go-micro/plugins/server/http/v3 v3.0.0-20210403073940-e7a7e3a05092
 	github.com/asim/go-micro/plugins/wrapper/select/roundrobin/v3 v3.0.0-20210403073940-e7a7e3a05092
 	github.com/asim/go-micro/plugins/wrapper/select/shard/v3 v3.0.0-20210403073940-e7a7e3a05092
-	github.com/asim/go-micro/v3 v3.5.2-0.20210630062103-c13bb07171bc
+	github.com/asim/go-micro/v3 v3.6.1-0.20210831143116-05a299b76c7c
 	github.com/gin-gonic/gin v1.7.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/protobuf v1.5.2
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0
-	github.com/micro/cli/v2 v2.1.2
 	github.com/pborman/uuid v1.2.1
+	github.com/urfave/cli/v2 v2.3.0
 	golang.org/x/net v0.0.0-20210510120150-4163338589ed
 	google.golang.org/genproto v0.0.0-20210624195500-8bfb893ecb84
 	google.golang.org/grpc v1.38.0
+	google.golang.org/protobuf v1.26.0
 )
--- a/examples/go.sum
+++ b/examples/go.sum
@ -102,8 +102,9 @@ github.com/asim/go-micro/plugins/wrapper/select/roundrobin/v3 v3.0.0-20210403073
 github.com/asim/go-micro/plugins/wrapper/select/shard/v3 v3.0.0-20210403073940-e7a7e3a05092 h1:YU1Qks1LnRQU/b9UbHz0V1ZMjlWcuQmPf95g403VRiY=
 github.com/asim/go-micro/plugins/wrapper/select/shard/v3 v3.0.0-20210403073940-e7a7e3a05092/go.mod h1:W82nHY+YFENWaye4jazv6nX+OYru9T7It+wUqJA9Vc0=
 github.com/asim/go-micro/v3 v3.0.0-20210120135431-d94936f6c97c/go.mod h1:fAeb2KUnD3z4XwtQ91XFxw5zgGKhoTsLc6Ie81QdER4=
-github.com/asim/go-micro/v3 v3.5.2-0.20210630062103-c13bb07171bc h1:nbM89BiCBeWjJESWmf8BQj8ObK6HEQzc/Dj7uITXR/8=
 github.com/asim/go-micro/v3 v3.5.2-0.20210630062103-c13bb07171bc/go.mod h1:cNGIIYQcp0qy+taNYmrBdaIHeqMWHV5ZH/FfQzfOyE8=
+github.com/asim/go-micro/v3 v3.6.1-0.20210831143116-05a299b76c7c h1:CaJvJPUEbd5aBmCBhOHmWDHCQr2HCxyCkbBxHW7w/kY=
+github.com/asim/go-micro/v3 v3.6.1-0.20210831143116-05a299b76c7c/go.mod h1:UQd2JfP/+4goQxddksr2r6ZSaUXNIlVE8hlepbAx/DI=
 github.com/aws/aws-sdk-go v1.23.0/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.37.27/go.mod h1:hcU610XS61/+aQV88ixoOzUoG7v3b31pl2zKMmprdro=
 github.com/baiyubin/aliyun-sts-go-sdk v0.0.0-20180326062324-cfa1a18b161f/go.mod h1:AuiFmCCPBSrqvVMvuqFuk0qogytodnVFVSN5CeJB8Gc=
@ -466,7 +467,6 @@ github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m
 github.com/mattn/go-tty v0.0.0-20180219170247-931426f7535a/go.mod h1:XPvLUNfbS4fJH25nqRHfWLMa1ONC8Amw+mIA639KxkE=
 github.com/mattn/go-tty v0.0.3/go.mod h1:ihxohKRERHTVzN+aSVRwACLCeqIoZAWpoICkkvrWyR0=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
-github.com/micro/cli/v2 v2.1.2 h1:43J1lChg/rZCC1rvdqZNFSQDrGT7qfMrtp6/ztpIkEM=
 github.com/micro/cli/v2 v2.1.2/go.mod h1:EguNh6DAoWKm9nmk+k/Rg0H3lQnDxqzu5x5srOtGtYg=
 github.com/microcosm-cc/bluemonday v1.0.1/go.mod h1:hsXNsILzKxV+sX77C5b8FSuKF00vh2OMYv+xgHpAMF4=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
@ -679,7 +679,9 @@ github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLY
 github.com/urfave/cli v0.0.0-20171014202726-7bc6a0acffa5/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
 github.com/urfave/cli v1.22.1/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 github.com/urfave/cli v1.22.2/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
+github.com/urfave/cli v1.22.4 h1:u7tSpNPPswAFymm8IehJhy4uJMlUuU/GmqSkvJ1InXA=
 github.com/urfave/cli v1.22.4/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
+github.com/urfave/cli/v2 v2.3.0 h1:qph92Y649prgesehzOrQjdWyxFOp/QVM+6imKHad91M=
 github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/XcUArI=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=