monit-docker is a free and open-source, we develop it to monitor container status or resources and execute some commands inside containers or manage containers with dockerd, for example:
- reload php-fpm if memory usage is too high
- reload php-fpm if no free space in /dev/shm
- restart container if status is not running
- remove all containers
Using monit-docker in Docker with crond
docker-compose up -d
See docker-compose.yml and MONIT_DOCKER_CRONS environment variable to configure commands.
pip install monit-docker
| Variable | Description | Default |
|---|---|---|
MONIT_DOCKER_CONFIG |
Configuration file contents (e.g. export MONIT_DOCKER_CONFIG="$(cat monit-docker.yml)") |
|
MONIT_DOCKER_CONFFILE |
Configuration file path | /etc/monit-docker/monit-docker.yml |
MONIT_DOCKER_LOGFILE |
Log file path | /var/log/monit-docker/monit-docker.log |
MONIT_DOCKER_RUNTIMEDIR |
Runtime directory path | /run/monit-docker |
Restart containers with name starts with foo if memory usage percentage > 60% or cpu usage percentage > 90%:
monit-docker --name 'foo*' monit --cmd-if 'mem_percent > 60 ? restart' --cmd-if 'cpu_percent > 90 ? restart'
Stop containers with name starts with bar or foo and if cpu usage percentage greater than 60% and less than 70%:
monit-docker --name 'bar*' --name 'foo*' monit --cmd-if '60 > cpu_percent < 70 ? stop'
Kill containers with name starts with bar and status equal to pause or running:
monit-docker --name 'bar*' monit --cmd-if 'status in (pause,running) ? kill'
You can also use status argument, for example, restart containers with status paused or exited:
monit-docker -s paused -s exited monit --cmd 'restart'
Generate containers pidfile:
monit-docker monit --rsc pid
Reload php-fpm in container with image name contains /php-fpm/ if memory usage greater than 100 MiB:
monit-docker --image '*/php-fpm/*' monit --cmd-if 'mem_usage > 100 MiB ? (kill -USR2 1)'
Reload php-fpm in container with image name contains /php-fpm/ if /dev/shm percentage usage greater than 80%:
monit-docker --image '*/php-fpm/*' monit --cmd '(bash -c "[ $(df /dev/shm | sed \"s/\%//;\$!d\" | awk \"{print \$5}\") -gt 80 ] && kill -USR2 1")'
Run commands with aliases declared in configuration file (e.g.: monit-docker.yml.example):
Restart container id 4c01db0b339c if condition alias @status_not_running is true:
monit-docker --id 4c01db0b339c monit --cmd-if '@status_not_running ? restart'
Execute commands alias @start_pause containers with name starts with foo if condition alias @status_not_running is true:
monit-docker --name 'foo*' monit --cmd-if '@status_not_running ? @start_pause'
Remove force container group php if status is equal to running:
monit-docker --ctn-group php monit --cmd-if 'status == running ? @remove_force'
Restart containers group nodejs if memory usage percentage > 10% and cpu usage percentage > 60%:
monit-docker --ctn-group nodejs monit --cmd-if '@mem_gt_10pct_and_cpu_gt_60pct ? restart'
Remove force all containers:
monit-docker monit --cmd '@remove_force'
Run command below to get status with exit code for container named foo_php_fpm:
monit-docker --name foo_php_fpm monit --rsc status
An error occurred if exit code is greater than 100.
| Exit code | Description |
|---|---|
| 0 | Running |
| 10 | Created |
| 20 | Paused |
| 30 | Restarting |
| 40 | Removing |
| 50 | Exited |
| 60 | Dead |
| 114 | Not found |
Run command below to get CPU usage percentage with exit code for container named foo_php_fpm:
monit-docker --name foo_php_fpm monit --rsc cpu_percent
An error occurred if exit code is greater than 100.
Run command below to get memory usage percentage with exit code for container named foo_php_fpm:
monit-docker --name foo_php_fpm monit --rsc mem_percent
An error occurred if exit code is greater than 100.
We can also monitoring containers cpu_percent and mem_percent resources with M/Monit.
check program docker.foo_php_fpm.status with path "/usr/bin/monit-docker --name foo_php_fpm monit --rsc status"
group monit-docker
if status = 114 for 2 cycles then alert # container not found
if status != 0 for 2 cycles then exec "/usr/bin/monit-docker --name foo_php_fpm monit --cmd restart" # container not running
check program docker.foo_php_fpm.cpu with path "/usr/bin/monit-docker -s running --name foo_php_fpm monit --rsc cpu_percent"
group monit-docker
if status > 100 for 2 cycles then alert
if status > 70 for 2 cycles then alert
if status > 80 for 4 cycles then exec "/usr/bin/monit-docker --name foo_php_fpm monit --cmd reload"
check program docker.foo_php_fpm.mem with path "/usr/bin/monit-docker -s running --name foo_php_fpm monit --rsc mem_percent"
group monit-docker
if status > 100 for 2 cycles then alert
if status > 70 for 2 cycles then alert
if status > 80 for 4 cycles then exec "/usr/bin/monit-docker --name foo_php_fpm monit --cmd '(kill -USR2 1)'"
check program docker.foo_php_fpm.pid with pidfile /run/monit-docker/foo_php_fpm.pid
group monit-docker
if changed pid then alert
Get all resources statistics for all containers in json format:
monit-docker stats --output json
{
"flamboyant_chaplygin": {
"status": "running",
"mem_percent": 0.03,
"net_tx": "0.0 B",
"cpu_percent": 0,
"mem_usage": "2.52 MiB",
"io_read": "3.5 MB",
"io_write": "0.0 B",
"net_rx": "25.2 kB",
"mem_limit": "7.27 GiB",
"pid": "3943"
}
}
{
"practical_proskuriakova": {
"status": "running",
"mem_percent": 0.04,
"net_tx": "0.0 B",
"cpu_percent": 0,
"mem_usage": "2.61 MiB",
"io_read": "24.6 kB",
"io_write": "0.0 B",
"net_rx": "25.0 kB",
"mem_limit": "7.27 GiB",
"pid": "3990"
}
}Get all resources statistics for all containers in text format:
monit-docker stats --output text
flamboyant_chaplygin|mem_usage:2.52 MiB|mem_limit:7.27 GiB|mem_percent:0.03|cpu_percent:0.0|io_read:3.5 MB|io_write:0.0 B|net_tx:0.0 B|net_rx:43.5 kB|status:running
practical_proskuriakova|mem_usage:2.61 MiB|mem_limit:7.27 GiB|mem_percent:0.04|cpu_percent:0.0|io_read:24.6 kB|io_write:0.0 B|net_tx:0.0 B|net_rx:43.3 kB|status:running
Get status and memory usage for group nodejs:
monit-docker --ctn-group nodejs stats --rsc status --rsc mem_usage