Setting up Nginx Proxy in Docker using Ansible - nginx

Question

I am attempting to setup an nginx container that serves as a proxy to another container I have setup. I would like to automate this setup as I need to deploy a similar setup across several servers. For this I am using Ansible.
Here is my nginx.conf:
events {
worker_connections 1024;
}
http {
server {
listen 8080;
location / {
proxy_pass http://192.168.1.14:9000;
}
}
}
Here is the relevant part of my Ansible YAML file:
- name: Install Nginx
docker:
name: nginx
image: nginx
detach: True
ports:
- 8080:8080
volumes:
- /etc/docker/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
When I first run my playbook, nginx is running but is not bound to 8080 as seen here:
6a4f610e86d nginx "nginx -g 'daemon off" 35 minutes ago Up Less than a second 80/tcp, 443/tcp nginx
However, if I run the nginx container directly with:
docker run -d -v /etc/docker/nginx/nginx.conf:/etc/nginx/nginx.conf:ro -p 8080:8080 nginx
nginx and my proxy runs as expected and is listening on 8080:
c3a46421045c nginx "nginx -g 'daemon off" 2 seconds ago Up 1 seconds 80/tcp, 443/tcp, 0.0.0.0:8080->8080/tcp determined_swanson
Any idea why it works one way but not the other?
Update
Per the guidance given in the selected answer, I updated my YAML file thusly:
- name: Install Nginx
docker:
name: nginx
image: nginx
detach: True
ports:
- 8080:8080
expose:
- 8080
volumes:
- /etc/docker/nginx/nginx.conf:/etc/nginx/nginx.conf:ro

Answer 1

First, you need to make sure your nginx image EXPOSE the port 8080, and you can specify directly in your ansible yaml file:
expose
(added in 1.5)
List of additional container ports to expose for port mappings or links. If the port is already exposed using EXPOSE in a Dockerfile, you don't need to expose it again.
Then, the only other difference I see when considering the Ansible docker module is that the port are inside double-quotes:
ports:
- "8080:9000"
Also, if you want to prexypass to another container in the same docker daemon, you might want to use a link instead of a fixed IP address.
links:
- "myredis:aliasedredis"
That way, your nginx.conf includes a fixed rule:
proxy_pass http://aliasedredis:9000;