Coreos practice (1)-coreos initial experience

Coreos mainly includes the following:

(1) Minimum OS: Kernel + systemd

(2) run the application using docker

(3) Use fleet to manage Clusters

(4) using etcd for service discovery: a distributed K/V Storage engine stores configuration data

 

Download the vagrant coreos configuration file

$ Git clone https://github.com/coreos/coreos-vagrant.git

$ Vagrant up

$ Vagrant status

Current Machine states:

 

Core-01 running (virtualbox)

Core-02 running (virtualbox)

Core-03 running (virtualbox)

 

$ Ssh-add ~ /. Vagrant. d/insecure_private_key

Identity added:/users/yy/. vagrant. d/insecure_private_key (/users/yy/. vagrant. d/insecure_private_key)

 

$ Vagrant SSH core-01

Last login: Sun Sep 7 16:23:31 2014 from 10.0.2.2

Coreos (Beta)

[Email protected] ~ $ Fleetctl list-Machines

Machine IP metadata

542a4130... 172.17.8.101-

Bcb90abf... 172.17.8.102-

E6a8eaa9... 172.17.8.103-

 

Read and Write etcd

[Email protected] ~ $ Etcdctl set first-etcd-key "Hello World"

Hello World

[Email protected] ~ $ Etcdctl get first-etcd-Key

Hello World

 

On core-02, you can read the value corresponding to first-etcd-key:

[Email protected] ~ $ Etcdctl get first-etcd-Key

Hello World

You can also directly provide an API to read the corresponding key:

[Email protected] ~ $ Curl-l http: // 127.0.0.1: 4001/V1/keys/first-etcd-Key

{& Quot; Action & quot;: & quot; get & quot;, & quot; Key & quot;: & quot;/first-etcd-Key & quot;, & quot; Value & quot;: & quot; Hello World & quot;, & quot; index & quot;: 2264}

 

Use fleetctl to manage services

[Email protected] ~ $ Cat hello. Service

[Unit]

Description = my service

After = docker. Service

 

[Service]

Timeoutstartsec = 0

Execstartpre =-/usr/bin/docker kill hello

Execstartpre =-/usr/bin/docker RM hello

Execstartpre =/usr/bin/docker pull busybox

Execstart =/usr/bin/docker run -- name Hello busybox/bin/sh-c "While true; do echo Hello world; sleep 1; done"

Execstop =/usr/bin/docker stop hello

[Email protected] ~ $ Fleetctl load hello. Service

Job hello. Service loaded on 542a4130.../172.17.8.101

[Email protected] ~ $ Fleetctl start hello. Service

Job hello. Service launched on 542a4130.../172.17.8.101

 

View service status

[Email protected] ~ $ Fleetctl status hello. Service

● Hello. Service-my service

Loaded: loaded (/run/fleet/units/Hello. Service; linked-runtime)

Active: active (running) Since mon 2014-09-08 04:21:13 UTC; 1 min 25 s ago

Process: 1117 execstartpre =/usr/bin/docker pull busybox (code = exited, status = 0/success)

Process: 1108 execstartpre =/usr/bin/docker RM Hello (code = exited, status = 1/failure)

Process: 1046 execstartpre =/usr/bin/docker kill Hello (code = exited, status = 1/failure)

Main PID: 1185 (docker)

Cgroup:/system. Slice/Hello. Service

Container-1185/usr/bin/docker run -- name Hello busybox/bin/sh-c While true; do echo Hello world; sleep 1; done

 

SEP 08 04:22:28 core-01 docker [1185]: Hello World

SEP 08 04:22:29 core-01 docker [1185]: Hello World

SEP 08 04:22:30 core-01 docker [1185]: Hello World

SEP 08 04:22:31 core-01 docker [1185]: Hello World

SEP 08 04:22:32 core-01 docker [1185]: Hello World

SEP 08 04:22:33 core-01 docker [1185]: Hello World

SEP 08 04:22:34 core-01 docker [1185]: Hello World

SEP 08 04:22:35 core-01 docker [1185]: Hello World

SEP 08 04:22:36 core-01 docker [1185]: Hello World

SEP 08 04:22:37 core-01 docker [1185]: Hello World

 

[Email protected] ~ $ Docker PS

Container ID image Command created status ports names

Fa7084105f19 busybox: buildroot-2014.02/bin/sh-c 'while tr 2 minutes ago up 2 minutes Hello

 

View service status in another coreos

$ Vagrant SSH core-02 ---

Last login: Mon Sep 8 04:35:40 2014 from 10.0.2.2

Coreos (Beta)

[Email protected] ~ $ Fleetctl list-Units

Unit dstate tmachine state machine active

Hello. Service launched 542a4130.../172.17.8.101 launched 542a4130.../172.17.8.101 active

[Email protected] ~ $ Fleetctl status hello. Service

● Hello. Service-my service

Loaded: loaded (/run/fleet/units/Hello. Service; linked-runtime)

Active: active (running) Since mon 2014-09-08 04:21:13 UTC; 15 min ago

Process: 1117 execstartpre =/usr/bin/docker pull busybox (code = exited, status = 0/success)

Process: 1108 execstartpre =/usr/bin/docker RM Hello (code = exited, status = 1/failure)

Process: 1046 execstartpre =/usr/bin/docker kill Hello (code = exited, status = 1/failure)

Main PID: 1185 (docker)

Cgroup:/system. Slice/Hello. Service

Container-1185/usr/bin/docker run -- name Hello busybox/bin/sh-c While true; do echo Hello world; sleep 1; done

 

SEP 08 04:36:20 core-01 docker [1185]: Hello World

SEP 08 04:36:21 core-01 docker [1185]: Hello World

SEP 08 04:36:22 core-01 docker [1185]: Hello World

SEP 08 04:36:23 core-01 docker [1185]: Hello World

SEP 08 04:36:24 core-01 docker [1185]: Hello World

SEP 08 04:36:25 core-01 docker [1185]: Hello World

SEP 08 04:36:26 core-01 docker [1185]: Hello World

SEP 08 04:36:27 core-01 docker [1185]: Hello World

SEP 08 04:36:28 core-01 docker [1185]: Hello World

SEP 08 04:36:29 core-01 docker [1185]: Hello World

[Email protected] ~ $ Fleetctl destroy hello. Service

Destroyed hello. Service

 

References

[1] https://coreos.com/docs/quickstart/

YY brother
Source: http://www.cnblogs.com/hustcat/
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Coreos practice (1)-coreos initial experience