nginx Proxy

The sole purpose of this image is to create nginx proxies.

Usage

To build:

docker built -t="malkab/nginx_proxy" .

Do not upload this image to DockerHub, it makes no sense, for each of its builds are a customized case.

This image configure nginx proxies to dockerized applications. Proxy configurations are in the conf.d folder. A typical proxy looks like this:

server {
  listen 80;
  server_name whatever.server;
  
  location /gs_a/ {
    proxy_pass http://geoserver:8080/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
  }
	
  location /gs_b/ {
    proxy_pass http://geoserver:8085/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
  }
}

This means that the server is listening at entries to domain name geoservers.geographica.gs at port 80. This domain name is linking to the server's IP. Remember that multiple domains can be linked to a single machine. When the machine is reached from the given domain and port, nginx analyzes the resource asked (either gs_a or gs_b) and redirects to the appropiate host.

Those host are in fact dockerized applications linked with external_link to the nginx proxy. The nginx knows how to resolve the container names to their docker internal network IP, so it is capable of reaching them. This way, is innecesary in production to expose the ports of the dockerized applications: only the nginx proxy knows about them and as such everything is pretty much contained.

To attach a new dockerized application to the proxy, follow this steps:

• make sure the container is attached to the proxy container by adding it's name to the external_links directive in docker-compose.yml control file;

• make, for each new domain, a configuration file inside conf.d, or just add a new location to an existing one, pointing to the new dockerized application's web entry point;

• recreate the nginx proxy container:

docker stop nginx_proxy ; docker rm -v nginx_proxy ; docker-compose build ; docker-compose up -d

Also, don't forget to modify the 404 static HTML in html with something funny.

localhost usage

The use of localhost as server_name is discouraged. localhost is sometimes a pain because I'm a complete beginner in network management and such. To simulate different domain names on localhost, just edit /etc/hosts and add there additional entries to IP 127.0.0.1. Then .conf files can be created for this local domains.