Docker container HOST is 127.0.0.1, how to get to run the container in the real IP address?

[Former user]

Event:

Event:       Content match
Service:     US_dgateway_log_alert
Date:        Thu, 09 Mar 2017 10:27:53
Action:      alert
Host:        127.0.0.1
Description: content match:

[Tildeslash]

Please can you provide more details?:

1. Monit configuration
2. network interfaces on the docker host
3. describe what exactly you need to monitor

[Anwar Xiao]

set daemon 30 with start delay 1
set logfile   /var/log/monit/monit.log
set pidfile   /opt/monit/pid/monit.pid
set idfile    /opt/monit/id/.monit.id
set statefile /opt/monit/state/.monit.state

set ssl {
    verify     : enable, # verify SSL certificates (disabled by default but STRONGLY RECOMMENDED)
    selfsigned : allow   # allow self signed SSL certificates (reject by default)
}

set mailserver
    smtp.gmail.com port 587
    username "gogogo" password "zzzzzzzzzzzzzzzz"
    using ssl,smtp.163.com port 465
    username "gogogo" password "xxxxxxxxxxxxxxx"
    using SSLAUTO with timeout 15 seconds
    using hostname "163.com"

set eventqueue basedir /opt/monit/event/monit slots 200

set mail-format {
  from:    Monit <[e-mail]>
  subject: monit alert --  $EVENT $SERVICE
  message: :)                         
                Event:       $EVENT
                Service:     $SERVICE
                Date:        $DATE
                Action:      $ACTION
                Host:        $HOST
                Description: $DESCRIPTION
}

check file monit_config_file path /opt/monit/conf/monitrc
    if changed sha1 checksum
    then exec "/opt/monit/bin/monit -c /opt/monit/conf/monitrc reload"

check system $HOST
    group system
    if loadavg (1min) > 4 for 2 cycles then alert
    if loadavg (5min) > 2 for 2 cycles then alert
    if memory usage > 80% for 5 cycles then alert
    if swap usage > 65% then alert
    if cpu usage (user) > 95% for 4 times within 5 cycles then alert
    if cpu usage (system) > 85% for 4 times within 5 cycles  then alert
    if cpu usage (wait) > 65% for 4 times within 5 cycles then alert

check filesystem root with path /
    group system
    if space usage > 85% for 5 times within 15 cycles then alert

check network public with interface eth0
    if failed link then alert
    if changed link then alert
    if saturation > 90% then alert
    if download > 20 MB/s then alert
    if total upload > 100 GB in last hour then alert

include /opt/monit/monit.s/*

[Anwar Xiao]

Here's what I'm doing in the docker back to the details:

root@c6f6e22d5081:~# hostname -f
c6f6e22d5081
root@c6f6e22d5081:~# hostname -i
172.10.0.6

As I understand, the monit variable $HOST should not be the result of the hostname -f return; and the response is the result of the hostname -i return.

[Tildeslash]

Thank you for data.

Monit expands the $HOST to a name, which should match output of "hostname" command-line utility with no options.

When alert is triggered, the hostname is mapped to a FQDN name using getaddrinfo().

Please can you provide output of following commands?:

hostname
hostname --all-fqdns 
grep c6f6e22d5081 /etc/hosts

[Anwar Xiao]

from docker container, the output of following:

root@4c481dc8ed0b:~# hostname
4c481dc8ed0b
root@4c481dc8ed0b:~# hostname --all-fqdns 
4c481dc8ed0b 
root@4c481dc8ed0b:~# grep 4c481dc8ed0b /etc/hosts
172.10.0.5  4c481dc8ed0b
root@4c481dc8ed0b:~#

[Tildeslash]

Thanks for data. I think the problem may be related to issues #559 and #537 - the AI_ADDRCONFIG can reduce the getaddrinfo() result set.

Please can you test with Monit 5.21.0?

[Anwar Xiao]

I have been test, this issue not fix.

In fact, my idea is very simple, that is, in the docker container, when the alarm, Host docker IP, there are host IP.

Such as the host IP is: 10.0.4.9, started three docker, docker ip were 172.18.1.4, 172.18.1.5, 172.18.1.6

At this point when the docker container monit alarm, Host should be:

Host: 10.0.4.9_172.18.1.4
or
Host: 10.0.4.9_172.18.1.5
or
Host: 10.0.4.9_172.18.1.6

So that in a cluster environment it is easy to know which physical machine that a Docker alarm

[Tildeslash]

adding custom hostname to monit configuration is simple, just use string instead of "$HOST" macro in "check system", for example:

check system "10.0.4.9_172.18.1.4"

[Anwar Xiao]

OK, thanks