implementing reverse proxy with nginx and docker containers with different ports - nginx

Question

i have three docker containers on different ports and would like to implement reverse proxy with nginx to each of the containers so that i can navigate to each of the containers by passing a keyword instead of ports. Like Instead of http://localhost:3000 i want to pass like http://localhost/app1
I created the nginx image with below dockerfile.
FROM nginx:alpine
COPY nginx.conf /etc/nginx/nginx.conf
COPY index.html usr/share/nginx/html
and my nginx conf file looks like this:
worker_processes 1;
events { worker_connections 1024; }
http {
sendfile on;
upstream app1 {
server localhost:3000;
}
upstream app2 {
server localhost:3001;
}
server {
listen 3000;
location /app1 {
proxy_pass http://localhost:3000;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
}
server {
listen 3001;
location /app2 {
proxy_pass http://localhost:3001;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
}
}
but after creating the nginx container from the image. I see the container created. but when i tried to access with localhost it timed out so nginx is not running or did i miss something. I cannot load the container with localhost/app1 or app2 or even localhost is not working. help needed. thanks in advance.

Answer 1

You are exposing the ports 80 and 443 when you start the container but I don't see you listening to those ports in the nginx configuration.
Please try replacing listen 3000 by listen 80 and then try accessing localhost/app1
I can also see that you are using --link when you start your docker container. So I think you should use app1 and app2 instead of localhost. Please let me know if there is something that I missed so it isn't the case. You must also make sure that your applications are accessible on these ports (3000 and 3001).
Also your 2 locations should be in the same server block:
server {
listen 80;
location /app1 {
proxy_pass http://app1:3000;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
location /app2 {
proxy_pass http://app2:3001;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
}