Conmon

[WIP!] Basic slack alerts for failing containers

This is just a very lightweight golang project that will check for containers failing more than a certain amount in a certain timeframe. It'll then send a message to a slack webhook.

This is by no means meant to be a proper 'production monitoring solution' - it's just a quick, small sanity check. We've sometimes had a situation where a container would get stuck in a rapid crash/restart loop and use up a lot of resources on a QA/test server - it's just to give us a little heads up.

Usage (commandline)

conmon [-config=/path/to/config.yaml -hostname=my-custom-hostname -proxy=http://your-corporate-proxy.com:8080 -slackchannel=alerts --slackhook=http://hooks.slack.com/your-webhook]

Usage (docker)

docker run -v /var/run/docker.sock:/var/run/docker.sock -v $(pwd)/config.yaml:/config.yaml uogsoe/conmon:0.3.0 conmon -config /config.yaml

Config

The config file is a plain yaml file. Options are :

alert_dies: 2
alert_minutes: 5
alert_frequency: 10
slack_webhook: "http://your-slack-webhook-url"
slack_channel: "your-slack-channel-of-choice"
hostname: "custom-hostname-if-you-want"
proxy: "http://your-proxy-if-you-need-one"

alert_dies is the number of times a container can die in alert_minutes. The alert_frequency is how many minutes to wait before notifying you again about the same container.

Building

If you want to build this yourself, you can do (assuming you have golang installed)

go get -v github.com/ohnotnow/conmon/...
go build -a -o conmon .

You can also build your own docker image - have a look at the provided Dockerfile.

Notes

Conmon bases it's idea of 'a container' on the image name. So if you have multiple services running the same image and they fall over conmon treats them as one container. That's what made sense in my context, so there it is...