check_docker
Nagios/NRPE compatible plugins for checking docker based services. Currently there are two nagios checks
- check_docker which checks docker container health
- check_swarm which checks health of swarm nodes and services
With check_docker can use it to check and alert on
- memory consumption in absolute units (bytes, kb, mb, gb) and as a percentage (0-100%) of the container limit.
- CPU usages as a percentage (0-100%) of container limit.
- automatic restarts performed by the docker daemon
- container status, i.e. is it running?
- container health checks are passing?
- uptime, i.e. is it able to stay running for a long enough time?
- the presence of a container or containers matching specified names
- image version, does the running image match that in the remote registry?
- image age, when was the image built the last time?
With check_swarm you can alert
- if a node is not joined to a docker swarm
- if a service is running in a swarm
These checks can communicate with a local docker daemon socket file (default) or with local or remote docker daemons using secure and non-secure TCP connections.
These plugins require python 3. It is tested on 3.5 and greater but may work on older versions of 3.
Installation
With pip
pip3 install check_docker --or-- pip install check_docker
With curl
curl -o /usr/local/bin/check_docker https://raw.githubusercontent.com/timdaman/check_docker/master/check_docker/check_docker.py curl -o /usr/local/bin/check_swarm https://raw.githubusercontent.com/timdaman/check_docker/master/check_docker/check_swarm.py chmod a+rx /usr/local/bin/check_docker /usr/local/bin/check_swarm
With wget
wget -O /usr/local/bin/check_docker https://raw.githubusercontent.com/timdaman/check_docker/master/check_docker/check_docker.py wget -O /usr/local/bin/check_swarm https://raw.githubusercontent.com/timdaman/check_docker/master/check_docker/check_swarm.py chmod a+rx /usr/local/bin/check_docker /usr/local/bin/check_swarm
check_docker Usage
usage: check_docker.py [-h]
[--connection [/<path to>/docker.socket|<ip/host address>:<port>]
| --secure-connection [<ip/host address>:<port>]]
[--binary_units | --decimal_units] [--timeout TIMEOUT]
[--containers CONTAINERS [CONTAINERS ...]] [--present]
[--threads THREADS] [--cpu WARN:CRIT]
[--memory WARN:CRIT:UNITS] [--status STATUS] [--health]
[--uptime WARN:CRIT] [--image-age WARN:CRIT] [--version]
[--insecure-registries INSECURE_REGISTRIES [INSECURE_REGISTRIES ...]]
[--restarts WARN:CRIT] [--no-ok] [--no-performance] [-V]
Check docker containers.
optional arguments:
-h, --help show this help message and exit
--connection [/<path to>/docker.socket|<ip/host address>:<port>]
Where to find docker daemon socket. (default:
/var/run/docker.sock)
--secure-connection [<ip/host address>:<port>]
Where to find TLS protected docker daemon socket.
--binary_units Use a base of 1024 when doing calculations of KB, MB,
GB, & TB (This is default)
--decimal_units Use a base of 1000 when doing calculations of KB, MB,
GB, & TB
--timeout TIMEOUT Connection timeout in seconds. (default: 10.0)
--containers CONTAINERS [CONTAINERS ...]
One or more RegEx that match the names of the
container(s) to check. If omitted all containers are
checked. (default: ['all'])
--present Modifies --containers so that each RegEx must match at
least one container.
--threads THREADS This + 1 is the maximum number of concurent
threads/network connections. (default: 10)
--cpu WARN:CRIT Check cpu usage percentage taking into account any
limits. Valid values are 0 - 100.
--memory WARN:CRIT:UNITS
Check memory usage taking into account any limits.
Valid values for units are %,B,KB,MB,GB.
--status STATUS Desired container status (running, exited, etc).
--health Check container's health check status
--uptime WARN:CRIT Minimum container uptime in seconds. Use when
infrequent crashes are tolerated.
--image-age WARN:CRIT Maximum image age in days.
--version Check if the running images are the same version as
those in the registry. Useful for finding stale
images. Does not support login.
--insecure-registries INSECURE_REGISTRIES [INSECURE_REGISTRIES ...]
List of registries to connect to with http(no TLS).
Useful when using "--version" with images from
insecure registries.
--restarts WARN:CRIT Container restart thresholds.
--no-ok Make output terse suppressing OK messages. If all
checks are OK return a single OK.
--no-performance Suppress performance data. Reduces output when
performance data is not being used.
-V show program's version number and exit
check_swarm Usage
usage: check_swarm.py [-h]
[--connection [/<path to>/docker.socket|<ip/host address>:<port>]
| --secure-connection [<ip/host address>:<port>]]
[--timeout TIMEOUT]
(--swarm | --service SERVICE [SERVICE ...] | --ignore_paused)
[-V]
Check docker swarm.
optional arguments:
-h, --help show this help message and exit
--connection [/<path to>/docker.socket|<ip/host address>:<port>]
Where to find docker daemon socket. (default:
/var/run/docker.sock)
--secure-connection [<ip/host address>:<port>]
Where to find TLS protected docker daemon socket.
--timeout TIMEOUT Connection timeout in seconds. (default: 10.0)
--swarm Check swarm status
--service SERVICE [SERVICE ...]
One or more RegEx that match the names of the
services(s) to check.
--ignore_paused Don't require global services to be running on paused nodes
-V show program's version number and exit
Gotchas
- When using check_docker with older versions of docker (I have seen 1.4 and 1.5) –status only supports ‘running’, ‘restarting’, and ‘paused’.
- When using check_docker, if no container is specified, all containers are checked. Some containers may return critcal status if the selected check(s) require a running container.
- When using check_docker, --present cannot be used without --containers to indicate what to check the presence of.
