sixxta/pde

PDE

(Or, Prescriptive Data Exercise)

Using NGINX, Registrator, Consul and Consul-Template to Load Balance between Nginx Web Servers.

How to Run

docker-compose build                   #make sure there are no image conflicts
docker-compose up --scale nginx-web=5  #scale the web servers up and down with this command

Consul API is available on localhost:8500 and the web server is available on localhost - might want to change to a non-privileged port.

How it works

Registrator connects to the docker UNIX socket to get information on containers sent to Consul. Consul-template is used in both the LB Nginx Container to provide the LB nginx-web container endpoints, and in the Web Server Nginx containers to provide a list of all Containers.

Improvements

• Bootstrap Consul Server with 3 instances instead of one for HA, and add Clients across a larger pool of Container Instances/Kubernetes
• Add Service Health Checks (would necessitate another Dockerfile)
• Introduce a rsyslog, statsd, or similiar loging service for log consolidation in one endpoint
• Consul Connect would add a layer of authentication. TLS between the Nginx LB and Web Servers would prevent anonymous proxies
• Nginx Web Servers block would benefit from not being an <embed>

Load Handling

Scaling up the web servers to 55 containers used ~4 GB and 20% of my laptop's CPU. Could probably comfortably scale up the web servers up to 200 containers, and many more with a cluster of container instances. No limits found with performance of Consul/Registrator.

Sources

• Setting Up an NGINX Demo Environment
• Load Balancing with NGINX and Consul Template