The presentation contains details of how to set up a fully-fledged environment based on Docker Swarm and Traefk. You will see a multi-tier application stack consisting of Edge router running in the first layer, then the frontend application and NodeJS backend. This is a quite common setup used in a microservices architecture. If you are building a high available environment without a single point of failure, it can be interesting for you. The source code used in the presentation: https://github.com/jakubhajek/traefik-consul-swarm

1. Container
Orchestration with
TRAEFIK
On Docker Swarm
Jakub Hajek / Cometari
Technical consultant & Founder
July 25th, 2019

2. Introduction
• I am the owner and technical consultant working for Cometari
• I have been system admin since 1998.
• Cometari is an agency implementing DevOps culture, providing consultancy,
workshops and software services.
• Our areas of expertise are DevOps, Elastic Stack (log analysis), Cloud
Computing.
• We are very deeply involved in the travel tech industry, however our solutions
go much further than just integrating travel API’s.

3. —
“I strongly believe that implementing DevOps
culture, across the entire organisation, should
provide measurable value and solve the real
issue rather than generate a new one.”

4. What will be presented
• Key features of Traefik working together with Docker Swarm
• Demo of fully fledged environment running on 4 nodes working as Swarm
cluster.
• Three application stacks will be deployed:
• Replicated Traefik instances with Consul cluster (BETA)
• Frontend app with simple NodeJS Backend

5. TRAEFIK key features

6. TRAEFIK key features
• Modern HTTP reverse proxy and load balancer for micro services working with
Docker Swarm and Kubernetes - just need to point Traefik into your
orchestrator
• Continuously update configuration, no restarts required
• Integration with Let’s Encrypt!
• Immutable image deployed on a cluster
• Configuration done via Docker labels on a service level

7. Challenges with TRAEFIK and SSL

8. Challenges with HA and SSL
• We need to have more than one instance of Traefik to provide HA
• Each instance needs to have access to certificates which are already generated
• Docker keeps the persistence locally, no easy way to share the data for other
Traefik instances
• Each component should be stateless, so how to deal with persistence

9. What is the SOLUTION?

10. TRAEFIK with CONSUL CLUSTER
• Running Consul cluster consisting of 3+1 nodes
• Keeping the persistence data in Consul, Key - value store
• Each Traefik instance can have access to Consul
• Traefik can keep up to 100 SSL certs
• Data are compressed to reduce the size
• We can easily scale horizontally TRAEFIK instances and still have access to our
SSL certs

11. TRAEFIK IMAGE with built in SSL certs
• Custom image with Traefik with added SSL certs into the image
• Works perfectly if you bought certs from a external provider
• Scalability is simple, no need to care about data persistence

12. DOCKER SWARM key features

13. Declarative service model

14. Replicas =3
Scalability in SWARM

15. Routing mesh
NODE_3NODE_2NODE_1

16. Demo environment

17. Demo environment in details
• Running on 4 virtual machines accessible from Internet
• VM’s have already installed the latest version of Docker
• Swarm cluster is already created
• Three stacks are deployed: Traefik with Consul and App stack
• DNS round robin for each domains used in the demo
• Route 53 (AWS) manages health-checks to update DNS records in case of failure of any VMs
• Domains:
• node-app.labs.cometari.eu
• traefik.labs.cometari.eu
• consul.labs.cometari.eu
• viz.labs.cometari.eu

18. • 3 overlay networks
• SSL Certificates issued by Let’s Encrypt and managed via TRAEFIK
• Consul cluster stores SSL certificates in KV store
• TRAEFIK Edge router is connected with Consul cluster
• WEB server with Frontend app connected to NodeJS backend (optional
service: might be responsible for caching static content)
Demo environment in details

19. Diagram of demo environment

20. DOCKER overlay networks

21. Diagram of the architecture from the service
perspective

22. SHOW ME THE CODE!
Overview of STACK FILES!

23. Summary
• Fully fledged example of multi tier application stack
• Straightforward configuration, everything is code!
• Immutable images, custom configuration managed by injecting environment
variables
• Easy way to scale up / down a service
• Automatically exposed new services thanks to TRAEFIK, no need to prepare
manually a config files
• Managing of SSL certs is managed in easy way!
• Infrastructure as code!

24. Links
• The source code is available at https://github.com/jakubhajek/traefik-consul-
swarm
• The official Traefik documentation: https://docs.traefik.io/v1.7/configuration/
backends/docker/
• The official Docker Swarm documentation: https://docs.docker.com/engine/
swarm/
• Compose file version 3 references: https://docs.docker.com/compose/
compose-file/

25. Thank You!

26. Jakub Hajek
Cometari
@_jakubhajek
kuba@cometari.com