https://github.com/cloudnautique/cowcheck

A microservice for checking the health of a Rancher node
https://github.com/cloudnautique/cowcheck

Last synced: about 2 months ago
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A microservice for checking the health of a Rancher node

• Host: GitHub
• URL: https://github.com/cloudnautique/cowcheck
• Owner: cloudnautique
• License: apache-2.0
• Created: 2017-04-07T04:44:47.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-12-21T21:37:57.000Z (almost 7 years ago)
• Last Synced: 2024-07-31T07:15:36.828Z (5 months ago)
• Language: Go
• Size: 107 KB
• Stars: 8
• Watchers: 3
• Forks: 5
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-rancher - Cowcheck - A microservice for checking the health of a Rancher node (Rancher 1.0 / Community projects 1.0)

README

        
cowcheck

========

A microservice for checking the health of a [Rancher](http://rancher.com) node. 

Presents an HTTP interface on port `5050` for querying health status.

Calling `/` or `/health` will return `200 OK` when healthy and `503 Service Unavailable` when one

or more of its checks were unhealthy in the most recent evaluation cycle. Additionally, a prometheus 

endpoint can be found at `/metrics`. See [Prometheus](#prometheus_endpoint) section below.

## What does it check/monitor? 

* Rancher Metadata API

* Rancher DNS

* Disk space available on the node (both container data space and Docker/Moby metadata space)

                 

## How to use

### With an auto-scaling group

Run this as a container on each Rancher host that runs your containers. It will assert 

basic functionality of the Rancher stack is working such as DNS, Metadata API. When combined

with a fleet management service such as AWS Auto Scale Groups or Google Cloud Deployment Manager 

you can replace nodes automatically when they fail. Alternatively you can just monitor and alert 

by polling the endpoint periodically.  

                                                              

###  Prometheus Endpoint

Endpoint is available at `/metrics` on port `5050`. Following metrics are available: 

* `cowcheck_node_health`: The metric will be set to `0` when healthy and `1` when unhealthy.

* `docker_data_storage`: Amount of free Docker Data Storage space in bytes

* `docker_metadata_storage`: Amount of free Docker Metadata Storage space in bytes

### Configuration options

* `POLL_INTERVAL`: Time in seconds between evaluating checks

* `LOG_LEVL`: Level of logging verbosity

* `ENABLE_STORAGE_CHECK`: Enable storage check by setting to `true`. Disabled by default. Currently only supports `devicemapper` storage driver.

* `DATA_SPACE_THRESHOLD`: Minimum amount of storage in bytes before failing storage checks.

* `METADATA_SPACE_THRESHOLD`: Minimum amount of storage in bytes before failing storage checks.

* `DOCKER_API_VERSION`: The version of the Docker API to use when connecting to the local docker daemon (only for storage checks)

## Building

To build the binary:

`make build`

To create a Docker image: 

`make package`

## Running

`docker run --net=host -p 5050:5050 [image name]`

Or schedule with [Rancher](http://rancher.com) to run on all hosts as a 

[Global Service](https://docs.rancher.com/rancher/v1.6/en/cattle/scheduling/#global-service) (cattle) 

or [Daemonset](https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/) (kubernetes). 

## License

Licensed under the Apache License, Version 2.0 (the "License");

you may not use this file except in compliance with the License.

You may obtain a copy of the License at

[http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)

Unless required by applicable law or agreed to in writing, software

distributed under the License is distributed on an "AS IS" BASIS,

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and

limitations under the License.