5a66991bb3
updating the kubernetes release to the latest in main go.mod Signed-off-by: Madhu Rajanna <madhupr007@gmail.com> |
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.. | ||
credentials | ||
internal | ||
auth.go | ||
client.go | ||
cluster.go | ||
compact_op.go | ||
compare.go | ||
config.go | ||
ctx.go | ||
doc.go | ||
kv.go | ||
lease.go | ||
LICENSE | ||
logger.go | ||
maintenance.go | ||
op.go | ||
options.go | ||
README.md | ||
retry_interceptor.go | ||
retry.go | ||
sort.go | ||
txn.go | ||
utils.go | ||
watch.go |
etcd/clientv3
etcd/clientv3
is the official Go etcd client for v3.
Install
go get go.etcd.io/etcd/client/v3
Warning: As etcd 3.5.0 was not yet released, the command above does not work. After first pre-release of 3.5.0 #12498, etcd can be referenced using:
go get go.etcd.io/etcd/client/v3@v3.5.0-pre
Get started
Create client using clientv3.New
:
cli, err := clientv3.New(clientv3.Config{
Endpoints: []string{"localhost:2379", "localhost:22379", "localhost:32379"},
DialTimeout: 5 * time.Second,
})
if err != nil {
// handle error!
}
defer cli.Close()
etcd v3 uses gRPC
for remote procedure calls. And clientv3
uses
grpc-go
to connect to etcd. Make sure to close the client after using it.
If the client is not closed, the connection will have leaky goroutines. To specify client request timeout,
pass context.WithTimeout
to APIs:
ctx, cancel := context.WithTimeout(context.Background(), timeout)
resp, err := cli.Put(ctx, "sample_key", "sample_value")
cancel()
if err != nil {
// handle error!
}
// use the response
For full compatibility, it is recommended to install released versions of clients using go modules.
Error Handling
etcd client returns 2 types of errors:
- context error: canceled or deadline exceeded.
- gRPC error: see api/v3rpc/rpctypes.
Here is the example code to handle client errors:
resp, err := cli.Put(ctx, "", "")
if err != nil {
switch err {
case context.Canceled:
log.Fatalf("ctx is canceled by another routine: %v", err)
case context.DeadlineExceeded:
log.Fatalf("ctx is attached with a deadline is exceeded: %v", err)
case rpctypes.ErrEmptyKey:
log.Fatalf("client-side error: %v", err)
default:
log.Fatalf("bad cluster endpoints, which are not etcd servers: %v", err)
}
}
Metrics
The etcd client optionally exposes RPC metrics through go-grpc-prometheus. See the examples.
Namespacing
The namespace package provides clientv3
interface wrappers to transparently isolate client requests to a user-defined prefix.
Request size limit
Client request size limit is configurable via clientv3.Config.MaxCallSendMsgSize
and MaxCallRecvMsgSize
in bytes. If none given, client request send limit defaults to 2 MiB including gRPC overhead bytes. And receive limit defaults to math.MaxInt32
.