go任务调度4（etcd安装和基本使用）

下载，解压，进入目录，运行：

[root@bogon etcd-v3.3.12-linux-amd64]# ./etcd --listen-client-urls ' http://0.0.0.0:2379 ' --advertise-client-urls ' http://0.0.0.0:2379 '

(本地etcd的端口)

etcd控制工具：

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl

(前面需要一个环境变量ETCDCTL_API=3)

put、get、del、--prefix：

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl put "name" "张三"

OK

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl get "name"

name

张三

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl del "name"

1

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl get "name"

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl put "/cron/jobs/job1" "{...json}"

OK

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl put "/cron/jobs/job2" "{...json}"

OK

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl get "/cron/jobs/job2"

/cron/jobs/job2

{...json}

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl get "/cron/jobs/job1"

/cron/jobs/job1

{...json}

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl get "/cron/jobs/" --prefix

/cron/jobs/job1

{...json}

/cron/jobs/job2

{...json}

[root@bogon etcd-v3.3.12-linux-amd64]#

(带上--prefix表示get以/cron/jobs/开头的)

watch监听k-v的变化：

[root@bogon etcd-v3.3.12-linux-amd64]# ETCDCTL_API=3 ./etcdctl watch "/cron/jobs/" --prefix

PUT

/cron/jobs/job2

{...changed}

DELETE

/cron/jobs/job2

(如果watch后，其他窗口改变/删除等/cron/jobs/job2的值，会显示出来。etcd很适合做配置的分发，可以实时感受到变化)