Docker CentOS Installation Syslog

In a typical Linux server, some services themselves do not have logs and can only be viewed by tail-f/var/log/messages to view their run logs, such as Nrpe server. However, if you want to implement this functionality in a Docker container, it will take a bit of work. The steps are as follows:

1, installation Rsyslog

Yum Install Rsyslog

2. Start the Syslog service

# RSYSLOGD

3. Test whether the log is generated in messages

" Hello World "

It turns out that there is only one line in messages: "1 11:31:37 f2570fed2149 rsyslogd: [Origin software=" Rsyslogd "swversion=" 7.4.7 "x-pid=" 73 " x-info= "http://www.rsyslog.com" "Start", it can be determined that it does not work. The reason is: "The problem was, RHEL7 and Fedora We are use Journald, which listens on/dev/log for incoming messages. In RHEL7 and Fedora, Rsyslog actually reads messages from the journal via its API by default.But the all Docker containers run Systemd and Journald. (most don ' t). In order to get the rsyslogd-to-work the the the user wanted, he would has to modify the configuration file, /etc/rsyslog.conf ”。

The solution is as follows:

1. Modify the syslog configuration--# vi/etc/rsyslog.conf

12, set $OmitLocalLogging to Off3, commented out $IMJournalStateFile imjournal.state

2. Submit container to mirror, re-create container

[[email protected] home]# Docker commit f2570fed2149 centos_with_syslog:v1. 0  223:222 -v/dev/log:/dev/log-ti centos_with_syslog:v1. 0 /run. SH dc2eb83e80ced6f553eb1dd7032489d37b4d934a9126f61dfbd4d6a2243e98f1

3. Test verification

[email protected] home]# Docker Exec-ti dc2eb83e80ced6f553eb1dd7032489d37b4d934a9126f61dfbd4d6a2243e98f1/bin/Bash[[email protected]/]# Logger"Hello everyone"[[Email protected]/]# exitexit[[email protected] home]#Tail-f/var/log/messages (note View Log in messages file on host)1  +: $:Wuyilocalhost Docker: Time="2015-08-01t19:57:51+08:00"Level=Infomsg="-job log (exec_start:/bin/bash, DC2EB83E80CED6F553EB1DD7032489D37B4D934A9126F61DFBD4D6A2243E98F1, Centos_with_ syslog:v1.0) = OK (0)" the1  +: $:Wuyilocalhost Docker: Time="2015-08-01t19:57:51+08:00"Level=Infomsg="post/v1.18/exec/9ae97d0666bf5abcd8d95eb87d10c5d013a0f006c2cb1adc7ff8f7baaacf14fc/resize?h=37&w=191 " the1  +: $:Wuyilocalhost Docker: Time="2015-08-01t19:57:51+08:00"Level=Infomsg="+job execresize (9AE97D0666BF5ABCD8D95EB87D10C5D013A0F006C2CB1ADC7FF8F7BAAACF14FC, Notoginseng, 191)" the1  +: $:Wuyilocalhost Docker: Time="2015-08-01t19:57:51+08:00"Level=Infomsg="-job execresize (9AE97D0666BF5ABCD8D95EB87D10C5D013A0F006C2CB1ADC7FF8F7BAAACF14FC, Notoginseng, 191) = OK (0)" the1  +: -: thelocalhost logger:Hello everyone

Docker CentOS Installation Syslog