Public | Automated Build

Last pushed: a year ago
Short Description
Renders and continually checks `kubectl get` results.
Full Description

kubectl-watch

kubectl-watch is a docker image that allows a user to continuously check the
results of a kubectl get command, and pipe it through a template when the
results change.

The original purpose of the image was to help drive an automatic k8s edge
router that updated its configuration whenever services became available with
specific labels.

Usage:

To use kubectl-watch, you are basically configuring a kubectl get command
and then mount volumes for the templates and output.

Here's a docker-compose example:

label-watcher:
    image: ceroic/kubectl-watch
    volumes:
      - ~/.kube:/root/.kube:ro
      - ./templates:/var/kubectl-watch/templates
      - ./output:/var/kubectl-watch/output
    environment:
      TYPE: svc
      SELECTOR: app=my-app
      TEMPLATE: my-fancy-template.txt
      OUTPUT_FILE: my-fancy-output.txt

NOTE: This example assumes you are testing locally and mounts authentication
directly as a volume. Ideally in a production setting this container would be
running with access to a service account that authorizes kubectl to the k8s API.

Environment Variables:

kubectl-watch requires the following environment variables to work.

Variable Description
TYPE The k8s service type to pass to the kubectl get call.
SELECTOR The kubectl get label selector passed to the -l parameter
TEMPLATE The filename of the template to render. Needs to be available in the templates directory
OUTPUT_FILE The name of the file to output to the output directory.

Optional Environment Variables:

Variable Description
INTERVAL The amount of time between each check. Defaults to 5 seconds.

Volumes:

kubectl-watch assumes you will be mounting two volumes to the container at
run time.

Volume Internal Path Description
Templates /var/kubectl-watch/templates Templates available to render.
Output /var/kubectl-watch/output Where rendered templates are output to.

Template Syntax:

kubectl-watch renders all templates using the -o go-template-file and
--template= flags. All templates use Go template syntax. More information
can be found here:

https://golang.org/pkg/text/template/

Docker Pull Command
Owner
ceroic
Source Repository

Comments (0)