Frontend/Backend gateway

This Docker image is based on the nginx image, and configures automatically a gateway, that forwards requests to two backends, simulating the frontend/backend pattern. This image was created to simulate the behaviour of the Spring Cloud Gateway image, for doing the initial infrastructure deployment, before the real software is deployed. I usually use the mendhak/http-https-echo or containous/whoami images as the backend.

You can test it using this command:

docker run --rm -it \
    -p 8080:8080 -p 8443:8443 \
    -e FRONTEND_URL=https://httpbin.org/anything/frontend \
    -e BACKEND_URL=https://httpbin.org/anything/backend \
    okelet/front-back-gateway:1.0

Nginx will forward the requests according to this configuration:

• /api/* -> backend
• /* -> frontend

For example:

• http://127.0.0.1:8080/api/hello -> would return a JSON document, where the "url" field is https://httpbin.org/anything/backend/api/hello
• http://127.0.0.1:8080/index.html -> would return a JSON document, where the "url" field is https://httpbin.org/anything/frontend/index.html

You don't have to worry about invalid SSL certificates in the backends, as nginx, by default, doesn't check its validity when proxying the requests.

nginx is configured to listen in the ports HTTP/8080 and HTTPS/8443 using a self signed certificate, valid for 10 years.

Environment variables

• BACKEND_URL (mandatory): URL where requests under /api will be forwarded.
• FRONTEND_URL (mandatory): URL where requests not matching the previous route will be forwarded.
• DNS_RESOLVER (optional): nginx requires a DNS server to resolve the forwarded servers; if this value is not set, it will be guessed automatically from /etc/resolv.conf.

Test using docker-compose

A docker-compose.yml is included in the repo, so the image is easy to run and test.

docker-compose up -d                       # Start the containers
sleep 5                                    # Wait for containers to start
curl http://127.0.0.1:8080/index.html      # Returns Name: frontend, GET /index.html HTTP/1.1
curl http://127.0.0.1:8080/api/test        # Returns Name: backend, GET /api/test HTTP/1.1
docker-compose rm -sf                      # Stop and remove the containers

Repositories

This image is available in the following repositories:

• Docker Hub
• AWS Public ECR
• GitHub Packages