Docker Networks + Nginx + YAML

What is it?

The goal of this proxy is to attempt to hijack the traffic from services in the cloud by using a reverse proxy (namely, nginx).

Note: Please do not use in production setups, this is purely meant to be used in development only.

Getting Started

To use this image, you would need to have an exisitng docker network. There's no requirement on the docker network to use, but for local development it is recommended to use bridge.

To get started:

docker network create local-network

This command will create a docker network called local-network. This is required as the this image is meant to be used as a container that is attached to an existing network.

The network arquirecture is as follows:

Therefore, all the services have to be attached to a network.

Services

Defining through a file

Command to the container: serve file or debug file

Refer to the docker-compose.yml file

In the root project a file named proxy.yml defines basics of the proxy configuration and basics of services (optional).

proxy:
  port: 80  # nginx's port
  to:
    protocol: https
    host: www.google.com  # host to redirect unmatched locations
  server:
    name: proxy-name  # value of server_name

services:  # optional
  app:  # service name
    strict_match: True  # uses the '=' operator to match the location
    prefix:
      value: my-app
      pass_prefix: True  # if the prefix used in the location shall be passed to the proxied service
    protocol: http  # if HTTPS is required TLS/SSL is required + certs
    port: 5000  # container's port number
  another-app:  # service name
    # ...

Definition through Docker

Command to the container: serve docker or debug docker

Refer to the docker-compose.yml file

This image comes with dynamic discovery of services registered in a network. This means that on container startup, the container will request the Docker API for the connected containers in the current network.

Requirements:

Although is easy to set up, some exclusion is sometimes wished. So for the containers to be taken in consideration in the proxy's rules some docker labels need to be present.

• local.proxy.pass_prefix
  • "true" || "false"
• local.application.port
  • Container's exposed port
• local.appliaction.name
  • This will be used to name the upstream, the prefix and the path rule.

Example:

# docker-compose.yml
services:
  app:  # service name
    networks:
      local-network:
        aliases:
          - my-app  # so we can use "my-app"
    labels:
      local.application.port: "8080"
      local.application.name: "my-app"
      local.proxy.pass_prefix: "true"
networks:
  local-network:
    external:
      name: local-network

If no aliases are wished then the name of the service has to match with the label local.application.name. In the example above, the service name is app then the label shall have the value of app and no aliases.

This is the minimum set up in a docker-compose.yml file to set a service detected and registered in the proxy.

Prefixes

Example for prefixes:

• Requested URI: /my-app/hello/
  • prefix: my-app & pass_prefix: False the service will receive /hello/
  • prefix: my-app & pass_prefix: True the service will receive /my-app/hello/

Contact

• Arnulfo Solis