Traefik

Traefik is a modern HTTP reverse proxy and load balancer made to deploy microservices with ease. It supports several backends, including Docker.

Traefik global configuration is managed in a .toml file, located at /etc/traefik/traefik.toml in the container (also see this sample file). However, it is possible to override default behaviour on containers, or even on services.

Global configuration

For convenience, most of the global configuration is managed in the compose file, in the command section of traefik:

Setting	Description	Value
docker	Enable Docker configuration backend	N.A.
docker.swarmmode	Enable swarm mode on Træfik	true
docker.endpoint	Docker server endpoint: can be a tcp or a unix socket endpoint	unix:///var/run/docker.sock
docker.domain	Default domain used	${DOMAIN:-example.com}
docker.watch	Enable watch docker changes	true
web	Activate the webUI on port 8080	N.A.
debug	Enable debug mode	true
logLevel	Log level	ERROR

The configuration of entry points is handled separately, in a .toml file. By default, two entry points are provided: http on port 80 and https on port 443. Links to guides on entry points and TLS certificate setup are provided inside the file.

Service configuration

All service-specific configurations are also managed in the compose file, using container labels in the deploy section of every service.

Here follows the list of labels with short descriptions:

Label	Description
traefik.backend	Give a name to the generated backend for this container
traefik.backend.loadbalancer.method	Set the load balancer algorithm
traefik.backend.loadbalancer.sticky	Enable backend sticky sessions
traefik.backend.loadbalancer.swarm	Use Swarm's inbuilt load balancer
traefik.backend.circuitbreaker.expression	Create a circuit breaker to be used against the backend, preventing high loads on failing servers
traefik.port	Register this port: useful when the container exposes multiples ports
traefik.enable	Enable this container in Traefik
traefik.frontend.rule	Override the default frontend rule
traefik.frontend.passHostHeader	Forward client Host header to the backend
traefik.frontend.entryPoints	Assign this frontend to entry points
traefik.docker.network	Set the docker network to use for connections to this container

Here follows the list of labels with values for services that are enabled in Traefik:

Label	Monasca Log API	Elasticsearch	Kibana
traefik.backend	monasca-log-api	elasticsearch	kibana
traefik.backend.loadbalancer.method	wrr	wrr	wrr
traefik.backend.loadbalancer.sticky	N.A. (default: false)	false	true
traefik.backend.loadbalancer.swarm	false	false	false
traefik.backend.circuitbreaker.expression	N.A.	NetworkErrorRatio() > 0.5	NetworkErrorRatio() > 0.5
traefik.port	8090	9200	5601
traefik.enable	true	true	true
traefik.frontend.rule	Host:${DOMAIN:-example.com};	Host:elastic.${DOMAIN:-example.com}	Host:kibana.${DOMAIN:-example.com}
	Method:POST,HEAD,GET;
	PathPrefix:/v3.0,/healthcheck
traefik.frontend.passHostHeader	false	false	false
traefik.frontend.entryPoints	https	https	https
traefik.docker.network	backend	backend	backend