CentOS 7.X 搭建时间服务器 --- chrony

之前centos6我们一直用的ntp时间服务器，虽然到CentOS7上也可以装ntp。但是各种坑啊。这次换一个时间同步工具---->chrony

=========================环境========================

server端

[root@zabbix ~]# hostname
zabbix
[root@zabbix ~]# hostname -I
10.0.0.120 172.16.1.120 

先说下环境，我这里是用ansible批量执行的。server端为外网为10.0.0.120。
目标是让客户端四台机器做到时间同步，一秒不差

小提示：在利用ansible批量分发文件的时候，覆盖文件是一件很危险的事，如果原文件存在，最好先备份。其实不管是ansible还是其它操作，覆盖都是很危险的

[root@zabbix ~]# cat /etc/ansible/hosts
[client]
172.16.1.51
172.16.1.52
172.16.1.53
172.16.1.250

防火墙关闭：

[root@zabbix ~]# systemctl status firewalld.service
???firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)

selinux关闭:

[root@zabbix ~]# getenforce
Disabled

[root@localhost ~]# systemctl status chrony
● chrony.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)  

========================服务端=========================

1.安装chrony(所有机器)

yum install chrony -y

2.启动chrony

[root@zabbix ~]# systemctl start chronyd.service
[root@zabbix ~]# systemctl status chronyd.service
???chronyd.service - NTP client/server
   Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled)
   Active: active (running) since Sat 2017-05-27 11:47:43 CST; 4s ago

3.编辑配置文件（注意：现在是服务器端的修改）

     22 allow 10.0.0.0/24
     23
     24 # Listen for commands only on localhost.
     25 bindcmdaddress 127.0.0.1
     26 bindcmdaddress ::1
     27
     28 # Serve time even if not synchronized to any NTP server.
     29 local stratum 10  

#第22行设置为本网段
#第29行的注释取消

4.查看配置文件如下

[root@zabbix ~]# egrep -v "#|^$" /etc/chrony.conf
server ntp1.aliyun.com
server time1.aliyun.com
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
allow 10.0.0.0/24
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
local stratum 10
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
noclientlog
logchange 0.5
logdir /var/log/chrony

5.重启时间同步服务

[root@zabbix ~]# systemctl restart chronyd.service   

======================客户端=====================

方法一

客户端的配置文件是同一个文件（/etc/chrony.conf）

1.删掉哪些没用的server xxxxxxxxxx iburst

1 # Use public servers from the pool.ntp.org project.
2 # Please consider joining the pool (http://www.pool.ntp.org/j    oin.html).
3 server  10.0.0.120      iburst
4 # Ignore stratum in source selection.  

2.在server端把配置文件编辑好然后用ansible批量分发过去

[root@zabbix ~]# ansible client -m copy -a "src=/root/chrony.conf dest=/etc/"
172.16.1.250 | SUCCESS => {
    "changed": true,
    "checksum": "52bda81d895de3c7c54886d342e5eec074df757e",
    "dest": "/etc/chrony.conf",
    "gid": 0,
    "group": "root",
    "md5sum": "aee9cc7faa70a0c189033cdb8692e4b1",
    "mode": "0644",
    "owner": "root",
    "size": 1038,
    "src": "/root/.ansible/tmp/ansible-tmp-1495860905.35-183232559888238/source",
    "state": "file",
    "uid": 0
}
172.16.1.53 | SUCCESS => {
    "changed": true,
    "checksum": "52bda81d895de3c7c54886d342e5eec074df757e",
    "dest": "/etc/chrony.conf",
    "gid": 0,
    "group": "root",
    "md5sum": "aee9cc7faa70a0c189033cdb8692e4b1",
    "mode": "0644",
    "owner": "root",
    "size": 1038,
    "src": "/root/.ansible/tmp/ansible-tmp-1495860905.34-134007063835838/source",
    "state": "file",
    "uid": 0
}
172.16.1.51 | SUCCESS => {
    "changed": true,
    "checksum": "52bda81d895de3c7c54886d342e5eec074df757e",
    "dest": "/etc/chrony.conf",
    "gid": 0,
    "group": "root",
    "md5sum": "aee9cc7faa70a0c189033cdb8692e4b1",
    "mode": "0644",
    "owner": "root",
    "size": 1038,
    "src": "/root/.ansible/tmp/ansible-tmp-1495860905.43-104570916452677/source",
    "state": "file",
    "uid": 0
}
172.16.1.52 | SUCCESS => {
    "changed": true,
    "checksum": "52bda81d895de3c7c54886d342e5eec074df757e",
    "dest": "/etc/chrony.conf",
    "gid": 0,
    "group": "root",
    "md5sum": "aee9cc7faa70a0c189033cdb8692e4b1",
    "mode": "0644",
    "owner": "root",
    "size": 1038,
    "src": "/root/.ansible/tmp/ansible-tmp-1495860905.43-40575778655199/source",
    "state": "file",
    "uid": 0
}

3.启动同步服务，防火墙也需要关闭

[root@zabbix ~]# ansible client -m shell -a "systemctl start chronyd.service"
172.16.1.53 | SUCCESS | rc=0 >>

172.16.1.250 | SUCCESS | rc=0 >>

172.16.1.52 | SUCCESS | rc=0 >>

172.16.1.51 | SUCCESS | rc=0 >>

4.注意客户端时间同步定时任务关闭

[root@zabbix ~]# ansible client -m shell -a "crontab -l"
172.16.1.51 | SUCCESS | rc=0 >>

172.16.1.250 | SUCCESS | rc=0 >>

172.16.1.53 | SUCCESS | rc=0 >>

172.16.1.52 | SUCCESS | rc=0 >>

5.Centos7依然可以用ntpdate命令同步时间

[root@zabbix ~]# ansible client -m shell -a "ntpdate 10.0.0.120"
172.16.1.53 | SUCCESS | rc=0 >>
27 May 13:05:57 ntpdate[26817]: adjust time server 10.0.0.120 offset -0.001686 sec

172.16.1.250 | SUCCESS | rc=0 >>
27 May 13:05:57 ntpdate[17419]: adjust time server 10.0.0.120 offset -0.004419 sec

172.16.1.52 | SUCCESS | rc=0 >>
27 May 13:05:57 ntpdate[50111]: adjust time server 10.0.0.120 offset -0.004410 sec

172.16.1.51 | SUCCESS | rc=0 >>
27 May 13:05:57 ntpdate[114089]: adjust time server 10.0.0.120 offset -0.000597 sec

6.查看时间，现在已经都同步了，一秒不差

[root@zabbix ~]# ansible client -m shell -a "date"
172.16.1.250 | SUCCESS | rc=0 >>
Sat May 27 13:06:04 CST 2017

172.16.1.51 | SUCCESS | rc=0 >>
Sat May 27 13:06:04 CST 2017

172.16.1.53 | SUCCESS | rc=0 >>
Sat May 27 13:06:04 CST 2017

172.16.1.52 | SUCCESS | rc=0 >>
Sat May 27 13:06:04 CST 2017

方法二：放入定时任务

[root@zabbix ~]# ansible client -m cron -a "name='time sync' minute=*/5 job='/usr/sbin/ntpdate 10.0.0.120 &>/dev/null'"
172.16.1.51 | SUCCESS => {
    "changed": true,
    "envs": [],
    "jobs": [
        "time sync"
    ]
}
172.16.1.52 | SUCCESS => {
    "changed": true,
    "envs": [],
    "jobs": [
        "time sync"
    ]
}
172.16.1.53 | SUCCESS => {
    "changed": true,
    "envs": [],
    "jobs": [
        "time sync"
    ]
}
172.16.1.250 | SUCCESS => {
    "changed": true,
    "envs": [],
    "jobs": [
        "time sync"
    ]
}

[root@zabbix ~]# ansible client -m shell -a "crontab -l"
172.16.1.51 | SUCCESS | rc=0 >>
#Ansible: time sync
*/5 * * * * /usr/sbin/ntpdate 10.0.0.120 &>/dev/null

172.16.1.52 | SUCCESS | rc=0 >>
#Ansible: time sync
*/5 * * * * /usr/sbin/ntpdate 10.0.0.120 &>/dev/null

172.16.1.53 | SUCCESS | rc=0 >>
#Ansible: time sync
*/5 * * * * /usr/sbin/ntpdate 10.0.0.120 &>/dev/null

172.16.1.250 | SUCCESS | rc=0 >>
#Ansible: time sync
*/5 * * * * /usr/sbin/ntpdate 10.0.0.120 &>/dev/null