Using Nginx on Docker to redirect HTTP to HTTPS

I had a website running using HTTPS behind a load balancer, and didn’t want to bother setting up HTTP as well. Instead, I configured the load balancer to point to a very simple Nginx webserver that does nothing else than redirecting HTTP to HTTPS. So from the application side I only had to take care of HTTPS and could ignore additional configuration. As a nice side-effect, the Nginx redirection is generic so that I only need to run a single instance for all my applications.

Since I don’t need anything else than Nginx on the Docker image, I used Alpine Linux as a base and added Nginx, or more precisely the preconfigured Nginx alpine-stable docker image from https://hub.docker.com/_/nginx/. The Dockerfile looks like the following:

FROM nginx:alpine

EXPOSE 80
COPY nginx.conf /etc/nginx/nginx.conf

FROM nginx:alpine

EXPOSE 80

COPY nginx.conf /etc/nginx/nginx.conf

And the related nginx.conf file, which gets copied when the docker image is created like this:

events {

}
http {
  server {
    listen       80;
    location / {
      return 301 https://$host$request_uri;
    }
  }
}

events {

}

http {

server {

listen 80;

location / {

return 301 https://$host$request_uri;

}

Assuming the Dockerfile and nginx.conf are in the same directory, a simple docker build command creates the docker image which can be loaded into your docker host. Writing a simple script to include this step in your build automation should be fairly trivial, depending on your needs.