check_docker
A Nagios check to check some basic statistics reported by the Docker daemon. Additionally validates the absence of Ghost containers and may optionally be made to require the presence of a container running from a particular image tag.
check_docker
is written in Go and is multi-threaded to keep the
drag time low on your Nagios server. It makes two API requests to the
Docker daemon, one to /info
and one to /containers/json
and processes the results, all simultaneously.
It is built using the the go_nagios framework.
Installing
If you would rather not build the binaries yourself, you can install compiled, statically-linked binaries for Linux or MacOSX. Simply download the tarball, extract it and use the binary of your choice.
Building
go get github.com/newrelic/go_nagios
go build
Usage
Usage of ./check_docker:
-base-url="http://docker-server:2375": The Base URL for the Docker server
-container-name="": The name of a container that must be running on the Docker server
-warn-data-space=100: Warning threshold for Data Space
-crit-data-space=100: Critical threshold for Data Space
-warn-meta-space=100: Warning threshold for Metadata Space
-crit-meta-space=100: Critical threshold for Metadata Space
-image-id="": An image ID that must be running on the Docker server
-tls-cert="": Path to TLS cert file
-tls-key="": Path to TLS key file
-tls-ca="": Path to TLS CA file
-base-url
: Here you specify the base url of the docker server.
-container-name
: Allows you to specify the name of a container that should be running
on the server.
-image-id
: You can specify an image tag that needs to be running on the server for
certain cases where you have pegged a container to a server (e.g. each server
has a Nagios monitoring container running to report on server health). Will not
require any particular image if left off.
-(warn|crit)-(meta|data)-space
: the thresholds at which the named Nagios status codes
should be emitted. These are percentages, so -crit-data-space=95
would send
a CRITICAL response when the threshold of 95% is crossed. Defaults are 100%.
Contributions
Contributions are more than welcome. Bug reports with specific reproduction steps are great. If you have a code contribution you'd like to make, open a pull request with suggested code.
Pull requests should:
- Clearly state their intent in the title
- Have a description that explains the need for the changes
- Include tests!
- Not break the public API
Testing for Contributors
go test
can be run on 2 different platforms:
-
In Darwin(aufs), assuming you already setup Boot2Docker:
docker run -t -d --name named_container busybox:latest export DOCKER_IMAGE=busybox:latest export DOCKER_CONTAINER_NAME=named_container cd $GOPATH/src/github.com/newrelic/check_docker go get ./... && go test
-
In Linux(devicemapper), you are running the tests inside vagrant:
cd $GOPATH/src/github.com/newrelic/check_docker vagrant up --provider virtualbox vagrant ssh # Inside Vagrant sudo docker run -t -d --name named_container busybox:latest export DOCKER_IMAGE=busybox:latest export DOCKER_CONTAINER_NAME=named_container export GOPATH=/go cd $GOPATH/src/github.com/newrelic/check_docker go get ./... && go test
Copyright (c) 2014 New Relic, Inc. All rights reserved.