Traefik

As explained in Learn Docker in a Month of Lunches, Second Edition

Traefik is an open-source reverse proxy and load balancer that dynamically configures routing from service metadata and runtime discovery.

Traefik is a container-aware reverse proxy for exposing many applications through standard HTTP and HTTPS ports. It solves the problem of running multiple services without assigning each one a separate public port. section 20.0

Instead of maintaining a static proxy configuration for every application, Traefik watches the Docker Engine through the Docker API. Container labels describe routing rules, and Traefik builds its configuration while it runs. New deployments and configuration changes do not require restarting or reloading the proxy. section 20.4

A practical Traefik workflow includes:

• Start Traefik and open its dashboard to inspect the routers and proxied applications. section 20.4

Route a container with labels

A service can enable Traefik, match requests for whoami.local, and direct traffic to port 8080 using container labels. Deploying the service causes Traefik to discover it and build the router configuration automatically.

Figure 20.11 The Traefik dashboard shows you the configuration for all the apps being proxied.

Use the dashboard to inspect the routers and application configuration that Traefik has assembled. section 20.4

How Learn Docker in a Month of Lunches, Second Edition covers it

How deep it goes

Explains Docker discovery, labels, routing, HTTPS, load balancing, and sticky sessions through runnable workflows rather than proxy internals.

Examples

Uses whoami and image-gallery deployments, dashboard inspection, curl checks, HTTPS routes, scaling, and cookie-based session tests.

What it assumes

Assumes Docker containers and Compose workflows, while introducing reverse-proxy routing and container discovery through practical commands.

What you can do after

Operate Traefik with Docker Compose, label services, verify routes, configure HTTPS, and test balancing across replicas.

How it connects

Connects reverse proxies with Docker API discovery, container labels, HTTPS, load balancing, and sticky sessions.

liveBookmanning.com

Read Learn Docker in a Month of Lunches, Second Edition on liveBook Get the book at manning.com

Related concepts

• container labelconfigured by · A container label is a key/value metadata attribute attached to a container through its configuration.
• reverse proxykind of · A reverse proxy is a server-side intermediary that receives client requests, forwards them to backend servers or services, and relays their responses to clients.
• NGINXcontrasts with · NGINX is open-source web-server and reverse-proxy software that serves HTTP content, forwards requests, and can load-balance network traffic.
• session affinityimplemented by · Session affinity is a traffic-routing policy that directs successive requests from a client or session to the same backend instance.
• ingress controllerkind of · An ingress controller is a Kubernetes component that implements Ingress routing rules by directing external network traffic to services within a cluster.

This explainer was generated by Manning's knowledge graph from the text of Learn Docker in a Month of Lunches, Second Edition. The section links point to the parts of the book it draws on.