etcd 连接上之后无法使用 get 获取对应的值

[jamesjianpeng]

1. 本地启动 etcd

PS E:\etcd> .\bin\etcd.exe
2020-12-19 18:10:58.844408 I | etcdmain: etcd Version: 3.3.13
2020-12-19 18:10:58.881419 I | etcdmain: Git SHA: Not provided (use ./build instead of go build)
2020-12-19 18:10:58.882408 I | etcdmain: Go Version: go1.14.2
2020-12-19 18:10:58.882408 I | etcdmain: Go OS/Arch: windows/amd64
2020-12-19 18:10:58.893410 I | etcdmain: setting maximum number of CPUs to 8, total number of available CPUs is 8
2020-12-19 18:10:58.894421 N | etcdmain: failed to detect default host (default host not supported on windows_amd64)
2020-12-19 18:10:58.894421 W | etcdmain: no data-dir provided, using default data-dir ./default.etcd
2020-12-19 18:10:58.907408 I | embed: listening for peers on http://localhost:2380
2020-12-19 18:10:58.909409 I | embed: listening for client requests on localhost:2379
2020-12-19 18:10:58.969440 I | etcdserver: name = default
2020-12-19 18:10:58.970409 I | etcdserver: data dir = default.etcd
2020-12-19 18:10:58.970409 I | etcdserver: member dir = default.etcd\member
2020-12-19 18:10:58.970409 I | etcdserver: heartbeat = 100ms
2020-12-19 18:10:58.971410 I | etcdserver: election = 1000ms
2020-12-19 18:10:58.971410 I | etcdserver: snapshot count = 100000
2020-12-19 18:10:58.972408 I | etcdserver: advertise client URLs = http://localhost:2379
2020-12-19 18:10:58.972408 I | etcdserver: initial advertise peer URLs = http://localhost:2380
2020-12-19 18:10:58.972408 I | etcdserver: initial cluster = default=http://localhost:2380
2020-12-19 18:10:59.001407 I | wal: releasing file lock to rename "default.etcd\\member\\wal.tmp" to "default.etcd\\member\\wal"
2020-12-19 18:10:59.059615 I | etcdserver: starting member 8e9e05c52164694d in cluster cdf818194e3a8c32
2020-12-19 18:10:59.060407 I | raft: 8e9e05c52164694d became follower at term 0
2020-12-19 18:10:59.060407 I | raft: newRaft 8e9e05c52164694d [peers: [], term: 0, commit: 0, applied: 0, lastindex: 0, lastterm: 0]
2020-12-19 18:10:59.061408 I | raft: 8e9e05c52164694d became follower at term 1
2020-12-19 18:10:59.185408 W | auth: simple token is not cryptographically signed
2020-12-19 18:10:59.267407 I | etcdserver: starting server... [version: 3.3.13, cluster version: to_be_decided]
2020-12-19 18:10:59.268408 I | etcdserver: 8e9e05c52164694d as single-node; fast-forwarding 9 ticks (election ticks 10)
2020-12-19 18:10:59.268408 E | etcdserver: cannot monitor file descriptor usage (cannot get FDUsage on windows)
2020-12-19 18:10:59.269409 I | etcdserver/membership: added member 8e9e05c52164694d [http://localhost:2380] to cluster cdf818194e3a8c32
2020-12-19 18:11:00.080662 I | raft: 8e9e05c52164694d is starting a new election at term 1
2020-12-19 18:11:00.080662 I | raft: 8e9e05c52164694d became candidate at term 2
2020-12-19 18:11:00.081663 I | raft: 8e9e05c52164694d received MsgVoteResp from 8e9e05c52164694d at term 2
2020-12-19 18:11:00.081663 I | raft: 8e9e05c52164694d became leader at term 2
2020-12-19 18:11:00.103665 I | raft: raft.node: 8e9e05c52164694d elected leader 8e9e05c52164694d at term 2
2020-12-19 18:11:00.103665 I | etcdserver: setting up the initial cluster version to 3.3
2020-12-19 18:11:00.125663 N | etcdserver/membership: set the initial cluster version to 3.3
2020-12-19 18:11:00.135665 I | etcdserver/api: enabled capabilities for version 3.3
2020-12-19 18:11:00.135665 I | etcdserver: published {Name:default ClientURLs:[http://localhost:2379]} to cluster cdf818194e3a8c32
2020-12-19 18:11:00.136666 I | embed: ready to serve client requests
2020-12-19 18:11:00.137697 N | embed: serving insecure client requests on 127.0.0.1:2379, this is strongly discouraged!

2. 使用 etcdctl 添加一个键值对

PS E:\etcd\bin> .\etcdctl.exe set helloKey helloEtcd
helloEtcd
PS E:\etcd\bin> .\etcdctl.exe get helloKey
helloEtcd

3. 测试的脚本 main.js

const { Etcd3 } = require('etcd3');
const client = new Etcd3({ hosts: ['http://127.0.0.1:2379'] });
console.log(client);

(async () => {
  const fooValue = await client.get('helloKey').string()
  console.log(fooValue)
})();

4. 执行 main.js 的结果

PS E:\policy-ops\etcd-play> node .\main.js
Etcd3 {
  prefix: <Buffer >,
  pool: ConnectionPool {
    options: { hosts: [Array] },
    callOptionsFactory: undefined,
    globalPolicy: RetryPolicy {
      options: [Object],
      executor: [ExecuteWrapper],
      onGiveUpEmitter: [EventEmitter],
      onRetryEmitter: [EventEmitter],
      onSuccess: [Function],
      onFailure: [Function],
      onRetry: [Function],
      onGiveUp: [Function]
    },
    authenticator: Authenticator {
      options: [Object],
      credentials: [InsecureChannelCredentialsImpl],
      awaitingMetadata: null
    },
    hosts: [ [Host] ]
  },
  options: { hosts: [ 'http://127.0.0.1:2379' ] },
  kv: KVClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  },
  leaseClient: LeaseClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  },
  watchClient: WatchClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  },
  nsApplicator: NSApplicator { prefix: <Buffer > },
  watchManager: WatchManager {
    client: WatchClient { client: [ConnectionPool] },
    backoff: ExponentialBackoff { attempt: 0, delay: 0, options: [Object] },
    state: 0,
    watchers: [],
    expectedClosers: Set {},
    initialBackoff: ExponentialBackoff { attempt: 0, delay: 0, options: [Object] }
  },
  auth: AuthClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  },
  maintenance: MaintenanceClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  },
  cluster: ClusterClient {
    client: ConnectionPool {
      options: [Object],
      callOptionsFactory: undefined,
      globalPolicy: [RetryPolicy],
      authenticator: [Authenticator],
      hosts: [Array]
    }
  }
}
null
PS E:\policy-ops\etcd-play>

5. 问题

从第4步来看console.log(fooValue) 输出是 null，正确的值是 helloEtcd 才对