https://github.com/negz/kubernary
A canary app for Kubernetes (or anywhere really).
https://github.com/negz/kubernary
canary docker healthchecks kube2iam kubernetes statsd
Last synced: about 1 month ago
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A canary app for Kubernetes (or anywhere really).
- Host: GitHub
- URL: https://github.com/negz/kubernary
- Owner: negz
- License: apache-2.0
- Created: 2017-03-14T18:49:00.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2017-03-22T22:21:51.000Z (about 8 years ago)
- Last Synced: 2025-01-25T22:35:21.403Z (3 months ago)
- Topics: canary, docker, healthchecks, kube2iam, kubernetes, statsd
- Language: Go
- Size: 23.4 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# kubernary
Kubernary is a canary app for Kubernetes (or anywhere really).
Kubernary runs arbitrary checks on a regular interval, or on demand.
These checks can emulate the common work patterns of real services
inside your cluster and emit metrics. This can give you an early
warning when overall cluster functionality is degraded.
## Usage
Kubernary runs as a daemon. It runs all checks at a configurable interval.
Checks generally emit logs and metrics at run time.
```
$ docker run negz/kubernary /kubernary/kubernary --help
usage: kubernary []
Checks whether your Kubernetes cluster works.
Flags:
--help Show context-sensitive help (also try --help-long and
--help-man).
--no-stats Don't send statsd stats.
--listen=":10002" Address at which to expose HTTP health checks.
-d, --debug Run with debug logging.
--close-after=1m Wait this long at shutdown before closing HTTP
connections.
--kill-after=2m Wait this long at shutdown before exiting.
Args:
Address to which to send statsd metrics.
```
Kubernary exposes the following HTTP endpoints:
* `http://kubernary/quitquitquit` - Causes Kubernary to shutdown and exit
immediately.
* `http://kubernary/health` - Runs all checks on-demand.
The `/health` endpoint returns:
* `200 OK` - If all checks pass.
* `503 SERVICE UNAVAILABLE` - If one or more check fails.
* `500 INTERNAL SERVER ERROR` - If an error unrelated to a check occurs.
Along with the following JSON body:
```
{
"s3": {
"ok": true,
"error": ""
},
"failingcheck": {
"ok": false,
"error": "Kaboom!"
}
}
```
## Checks
Currently the only check is Amazon S3. This check ensures a Kubernary can read a
file from an S3 bucket, primarily as a way of validating that `kube2iam` is
functioning correctly in a Kubernetes cluster.
The check uses the following environment variables for configuration:
* `KUBERNARY_S3_BUCKET` - The bucket to read from.
* `KUBERNARY_S3_KEY` - The key to read within the bucket. Reading a very small
or zero length file is recommended.
The following statsd metrics are emitted by the check:
* `kubernary.s3.download.succeeded` - A count of successful S3 downloads.
* `kubernary.s3.download.failed` - A count of failed S3 downloads.
## Building
To build a Docker image run the following with a working Go environment:
```
$ scripts/build.sh
```
This (possibly somewhat brittle) script will build a Kubernary binary, and copy
it into a Docker image. You'll need to push it to ECR manually:
```
VERSION=$(git rev-parse -short HEAD)
docker push negz/kubernary:latest
docker push negz/kubernary:${VERSION}
```