etcd docker: curl is work, golang failed for DeadlineExceeded

[HanweiLi-cqu]

etcd docker deploy on my server. In my computer, curl is work. However, golang failed for DeadlineExceeded. Firewall-cmd strategy was set so that curl could work.

version: "3.5"
services:
  etcd:
    hostname: etcd
    image: bitnami/etcd:3
    deploy:
      replicas: 1
      restart_policy:
        condition: on-failure
    privileged: true
    volumes:
      - "/home/xxx/etcd/data:/opt/bitnami/etcd/data"
    environment:
      - "TZ=Asia/Shanghai"
      - "ETCD_NAME=node1"
      - "ETCD_ADVERTISE_CLIENT_URLS=http://0.0.0.0:2379"
      - "ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379"
      - "ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380"
      - "ETCD_INITIAL_ADVERTISE_PEER_URLS=http://0.0.0.0:2380"
      - "ALLOW_NONE_AUTHENTICATION=yes"
      - "ETCD_INITIAL_CLUSTER=node1=http://0.0.0.0:2380"
      - "ETCD_DATA_DIR=/opt/bitnami/etcd/data"
    ports:
      - 2379:2379
      - 2380:2380
    networks:
      - etcdnet

networks:
  etcdnet:
    name: etcdnet

I use curl command as below:

 curl -L http://my-server-ip:2379/v3/kv/put -X POST -d '{"key": "bmFtZQ==", "value":"emhhbmdzYW4="}'

and golang code as below:

cli, err := clientv3.New(clientv3.Config{
    Endpoints:   []string{"my-server-ip:2379"},
    DialTimeout: 5 * time.Second,
})
if err != nil {
    log.Fatal(err)
} else {
    log.Println("successfully connect etcd")
}
defer cli.Close()

ctx, cancel := context.WithTimeout(context.Background(), time.Second*20)
_, err = cli.Put(ctx, "sample_key", "sample_value")
statusRes, err := cli.Status(context.Background(), "my-server-ip:2379") // Waits here indefinitely
if err != nil {
    log.Fatal(err)
    log.Fatal(statusRes)
}
defer cancel()
if err != nil {
    log.Fatal(err)
}

This code return error:

rpc error: code = DeadlineExceeded desc = latest balancer error: last connection error: connection error: desc = "error reading server preface: EOF"

I've set up a firewall policy, so I don't think there should be a problem with the network, and curl is working.
So I'd like to ask if there is any other problem, or if it's really a problem with my configuration or network

[jmhbnz]

Hey @HanweiLi-cqu - Thanks for your question. This issue appears to be with your local environment.

Below is the reproduce script I ran which worked fine at my end:

cat << EOF > docker-compose.yaml                                                                                            
version: "3.5"                                                                                                               
services:                                                                                                                      
  etcd:                                                                                                                        
    hostname: etcd                                                                                                             
    image: bitnami/etcd:3                                                                                                      
    deploy:                                                                                                                    
      replicas: 1                                                                                                              
      restart_policy:                                                                                                          
        condition: on-failure                                                                                                  
    privileged: true                                                                                                           
    volumes:                                                                                                                   
      - "./data/:/opt/bitnami/etcd/data"                                                                           
    environment:                                                                                                               
      - "TZ=Asia/Shanghai"                                                                                                     
      - "ETCD_NAME=node1"                                                                                                      
      - "ETCD_ADVERTISE_CLIENT_URLS=http://0.0.0.0:2379"                                                                       
      - "ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379"                                                                          
      - "ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380"                                                                            
      - "ETCD_INITIAL_ADVERTISE_PEER_URLS=http://0.0.0.0:2380"                                                                 
      - "ALLOW_NONE_AUTHENTICATION=yes"                                                                                        
      - "ETCD_INITIAL_CLUSTER=node1=http://0.0.0.0:2380"                                                                       
      - "ETCD_DATA_DIR=/opt/bitnami/etcd/data"                                                                                 
    ports:                                                                                                                     
      - 2379:2379                                                                                                              
      - 2380:2380                                                                                                              
    networks:                                                                                                                  
      - etcdnet                                                                                                                
                                                                                                                               
networks:                                                                                                                      
  etcdnet:                                                                                                                     
    name: etcdnet
EOF


docker-compose up -d


cat << EOF > main.go
package main
import (
     "go.etcd.io/etcd/client/v3"
     "log"
     "time"
     "context"
 )
 func main() {                 
 cli, err := clientv3.New(clientv3.Config{
    Endpoints:   []string{"localhost:2379"},
    DialTimeout: 5 * time.Second,
})
if err != nil {
    log.Fatal(err)
} else {
    log.Println("successfully connect etcd")
}
defer cli.Close()

ctx, cancel := context.WithTimeout(context.Background(), time.Second*20)
_, err = cli.Put(ctx, "sample_key", "sample_value")
statusRes, err := cli.Status(context.Background(), "localhost:2379") // Waits here indefinitely
if err != nil {
    log.Fatal(err)
    log.Fatal(statusRes)
}
defer cancel()
if err != nil {
    log.Fatal(err)
}
}
EOF


go mod init example.com/example && go mod tidy


go run main.go 

etcdctl get sample_key

[HanweiLi-cqu]

Thank you for your reply!.
I tried running etcd on windows locally and it works.
But I also tried deploying with docker at WSL and still curl works, golang doesn't work. So I've tried it without docker technology. I used the following command on the server

etcd --listen-client-urls 'http://0.0.0.0:2379' --advertise-client-urls 'http://0.0.0.0:2379'

same error occur.

[jmhbnz]

Thanks for the update @HanweiLi-cqu. I don't run Windows so can't reproduce further but we've confirmed that the reproduce script above works as expected in Linux natively and Windows itself so the issue appears to be WSL specific.

See if you can spot anything in https://learn.microsoft.com/en-us/windows/wsl/networking otherwise perhaps raise an issue with WSL as I don't believe this is an issue on the etcd side.

If you are able to get to the bottom of this please do update this thread so others in the community using WSL can refer to it in future.