升级go1.17.1后etcd依赖报错解决

go版本升级到1.17.1后，go mod tidy 时候 etcd依赖报错：

go: common/modules/etcd imports
    go.etcd.io/etcd/clientv3 tested by
    go.etcd.io/etcd/clientv3.test imports
    github.com/coreos/etcd/auth imports
    github.com/coreos/etcd/mvcc/backend imports
    github.com/coreos/bbolt: github.com/coreos/bbolt@v1.3.6: parsing go.mod:
    module declares its path as: go.etcd.io/bbolt
            but was required as: github.com/coreos/bbolt

于是求助于网络，很多文章比较老旧，提供办法如下（仍不能解决）：

go mod init
 
go mod edit -replace github.com/coreos/bbolt@v1.3.4=go.etcd.io/bbolt@v1.3.4
 
go mod edit -replace google.golang.org/grpc@v1.29.1=google.golang.org/grpc@v1.26.0
 
go mod tidy

最后，经过通过升级Etcd依赖版本解决，正确方法如下：

1. 更新etcd依赖引入路径

   # 替换之前
   import(
       "go.etcd.io/etcd/clientv3"
   )
   # 替换之后
   import(
       "go.etcd.io/etcd/client/v3"
   )
   

2. 执行命令

   rm go.mod go.sum
   go mod init main
   go mod tidy
   go build .
   

之后go.mod中依赖大概是：

require (
    go.etcd.io/etcd/client/pkg/v3 v3.5.0 // indirect
    go.etcd.io/etcd/client/v3 v3.5.0 // indirect  
    google.golang.org/grpc v1.38.0 // indirect
)

总结：因为etcd v3版本接口和最新的grpc兼容，所以不用再像网上历史文章那样去处理，直接替换etcd包地址即可。