服务之间相互调用

README.md

@@ -237,6 +237,123 @@ func NewServiceContext(c config.Config, db *gorm.DB) *ServiceContext {
 
 ```
 
+编辑2调用其它服务 `internal/svc/servicecontext.go`：
+
+```go
+import (
+"fmt"
+"net"
+"strconv"
+"sync"
+"time"
+
+"lone-services/pkg/discovery"
+"lone-services/pkg/utils"
+"lone-services/services/order/internal/config"
+
+"github.com/zeromicro/go-zero/core/logx"
+"github.com/zeromicro/go-zero/zrpc"
+"gorm.io/gorm"
+)
+
+// 缓存条目
+type rpcClientCacheEntry struct {
+cli      zrpc.Client
+target   string
+expireAt time.Time
+}
+
+const rpcClientCacheTTL = 30 * time.Second //缓存过期时间
+
+var (
+rpcCacheLock sync.Mutex
+rpcCache     = make(map[string]*rpcClientCacheEntry)
+)
+
+func GetRpcClient(serviceName string) (zrpc.Client, error) {
+if serviceName == utils.StringEmpty {
+err := fmt.Errorf("rpc serviceName is empty")
+logx.Error(err)
+return nil, err
+}
+
+cacheKey := serviceName
+
+rpcCacheLock.Lock()
+entry, ok := rpcCache[cacheKey]
+if ok && time.Now().Before(entry.expireAt) {
+rpcCacheLock.Unlock()
+return entry.cli, nil
+}
+delete(rpcCache, cacheKey)
+rpcCacheLock.Unlock()
+
+inst, err := discovery.Pick(serviceName)
+if err != nil {
+err = fmt.Errorf("discovery pick %s failed: %w", serviceName, err)
+logx.Error(err)
+return nil, err
+}
+
+target := net.JoinHostPort(inst.IP, strconv.FormatUint(inst.Port, utils.NumberTen))
+
+cli := zrpc.MustNewClient(zrpc.RpcClientConf{
+Target:  target,
+Timeout: utils.RpcTimeOut, //rpc调用超时5s
+})
+
+rpcCacheLock.Lock()
+rpcCache[cacheKey] = &rpcClientCacheEntry{
+cli:      cli,
+target:   target,
+expireAt: time.Now().Add(rpcClientCacheTTL),
+}
+rpcCacheLock.Unlock()
+
+return cli, nil
+}
+
+type ServiceContext struct {
+Config config.Config
+DB     *gorm.DB
+Prefix string
+
+ExpressSvcName string //服务名
+}
+
+func NewServiceContext(c config.Config, db *gorm.DB) *ServiceContext {
+//启动仅读取配置，不建立rpc连接 多个服务就多个
+expressSvc := utils.GetConfigString("services.express")
+
+if expressSvc == utils.StringEmpty {
+logx.Error("config services.express empty")
+}
+
+svcCtx := &ServiceContext{
+Config:         c,
+DB:             db,
+Prefix:         utils.GetConfigString("mysql.prefix"),
+ExpressSvcName: expressSvc,
+}
+
+return svcCtx
+}
+
+
+调用方法logic中
+//调用其它服务实例
+//cli, err := svc.GetRpcClient(l.svcCtx.ExpressSvcName)
+//if err != nil {
+//	l.Logger.Errorf("get express rpc err: %v", err)
+//	//降级逻辑
+//	return l.out(utils.ErrorInternalServer, "express"+utils.ErrorInternalServer.Msg)
+//}
+//expClient := express.NewExpressClient(cli.Conn())
+//res, _ := expClient.Ping(context.Background(), &express.Request{})
+//l.Logger.Error("res: %v", res)
+
+```
+
 ### 7. 接入 Docker Compose
 
 在 `deploy/docker-compose.override.yml` 增加服务：