============ 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.

Installation

These plugins require Python 3.

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 [//docker.socket|:] | --secure-connection [:]] [--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 [//docker.socket|:] Where to find docker daemon socket. (default: /var/run/docker.sock) --secure-connection [:] 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']) --exclude-containers EXCLUDECONTAINERS [EXCLUDECONTAINERS ...] One or more containers to exclude.

--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.
--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 [//docker.socket|:] | --secure-connection [:]] [--timeout TIMEOUT] (--swarm | --service SERVICE [SERVICE ...] | --ignore-paused) [-V]

Check docker swarm.

optional arguments: -h, --help show this help message and exit --connection [//docker.socket|:] Where to find docker daemon socket. (default: /var/run/docker.sock) --secure-connection [:] Where to find TLS protected docker daemon socket. --timeout TIMEOUT Connection timeout in seconds. (default: 10.0) --swarm Check whether or not this node is connected to a swarm --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, 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.