/Containers On Demand

Containers On Demand

149
v1.2.0

Traefik Ondemand Plugin

Traefik middleware to start containers on demand.

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Features

  • Support for Docker containers
  • Support for Docker swarm mode, scale services
  • Support for Kubernetes Deployments and Statefulsets
  • Start your container/service on the first request
  • Automatic scale to zero after configured timeout upon last request the service received
  • Dynamic loading page (cloudflare or grafana cloud style)
  • Customize dynamic and loading pages

Demo

Usage

Plugin configuration

Strategies

Dynamic Strategy (default)

Serve an HTML page that self reload.

testData:
serviceUrl: http://ondemand:10000
name: TRAEFIK_HACKATHON_whoami
timeout: 1m
waitui: true

Blocking Strategy

Blocking strategy is enabled by setting waitui to false.

Instead of displaying a self refreshing page, the request hangs until the service is ready to receive the request.

The timeout is set by blockdelay.

testData:
serviceUrl: http://ondemand:10000
name: TRAEFIK_HACKATHON_whoami
timeout: 1m
waitui: false
blockdelay: 1m

Typical use case: an API calling another API

Custom loading/error pages

The loadingpage and errorpage keys in the plugin configuration can be used to override the default loading and error pages.

The value should be a path where a template that can be parsed by Go's html/template package can be found in the Traefik container.

An example of both a loading page and an error page template can be found in the pkg/pages/ directory in loading.html and error.html respectively.

The plugin will default to the built-in loading and error pages if these fields are omitted.

You must include <meta http-equiv="refresh" content="5" /> inside your html page to get auto refresh.

Example Configuration

testData:
serviceUrl: http://ondemand:10000
name: TRAEFIK_HACKATHON_whoami
timeout: 1m
waitui: false
blockdelay: 1m
loadingpage: /etc/traefik/plugins/traefik-ondemand-plugin/custompages/loading.html
errorpage: /etc/traefik/plugins/traefik-ondemand-plugin/custompages/error.html
ParameterTypeDefaultRequiredExampleDescription
serviceUrlstringemptyyeshttp://ondemand:10000The docker container name, or the swarm service name
namestringemptyyesTRAEFIK_HACKATHON_whoamiThe container/service to be stopped (docker ps docker service ls)
timeouttime.Duration1mno1m30sThe duration after which the container/service will be scaled down to 0
waituibooltruenotrueServes a self-refreshing html page when the service is scaled down to 0
blockdelaytime.Duration1mno1m30sWhen waitui is false, wait for the service to be scaled up before blockdelay
loadingpagestringemptyno/etc/traefik/plugins/traefik-ondemand-plugin/custompages/loading.htmlThe path in the traefik container for the loading page template
errorpagestringemptyno/etc/traefik/plugins/traefik-ondemand-plugin/custompages/error.htmlThe path in the traefik container for the error page template

Traefik-Ondemand-Service

The traefik-ondemand-service must be used to bypass Yaegi limitations.

Yaegi is the interpreter used by Traefik to load plugin and run them at runtime.

The docker library that interacts with the docker deamon uses unsafe which must be specified when instanciating Yaegi. Traefik doesn't, and probably never will by default.

Examples

  • ./examples/docker_classic/
  • ./examples/docker_swarm/
  • ./examples/multiple_containers/
  • ./examples/kubernetes/

Development

export TRAEFIK_PILOT_TOKEN=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx docker stack deploy -c docker-compose.yml TRAEFIK_HACKATHON

Authors

Alexis Couvreur (left) Alexandre Hiltcher (middle) Matthias Schneider (right)

Alexandre, Alexis and Matthias