Docker Nginx Hosts Cannot Be Resolved - docker

Question

I am trying to connect to a proxypass in docker I have setup but I keep getting:
8#8: *1 api.example.local could not be resolved (3: Host not found)
I can access the proxy by going to http://api.example.com in my browser, but not if I go through the nginx proxy pass. My nginx is as follows, and please note that:
Have ipv6 disabled
I am resolving to 127.0.0.11
server {
listen 80;
server_name api.example.local;
resolver 127.0.0.11 ipv6=off;
location / {
root /code/api/public_html/;
index index.php index.html index.htm;
try_files $uri $uri/ /index.php?rt=$uri&$args;
}
location ~ \.php$ {
root /code/api/public_html/;
fastcgi_pass php:9000;
fastcgi_index index.php;
#fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param ENV development;
fastcgi_param HTTPS off;
fastcgi_read_timeout 9600;
}
}
server {
index index.php index.html;
server_name www.example.local;
resolver 127.0.0.11 ipv6=off;
error_log /var/log/nginx/error.log;
access_log /var/log/nginx/access.log;
root /code/main/public_html;
location / {
root /code/main/public_html/;
index index.php index.html index.htm;
try_files $uri $uri/ /index.php?rt=$uri&$args;
}
location /api {
resolver 127.0.0.11 ipv6=off;
proxy_pass_header Set-Cookie;
proxy_pass_header P3P;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Fowarded-Host $host;
set $upstream api.example.local;
proxy_pass http://$upstream;
proxy_connect_timeout 60;
proxy_redirect off;
}
location ~ \.php$ {
root /code/main/public_html/;
fastcgi_pass php:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param ENV development;
fastcgi_param HTTPS off;
fastcgi_read_timeout 300;
}
}
I also have the domains in my /etc/hosts. The OS is Ubuntu 18.04.
127.0.0.1 localhost
127.0.1.1 my-comp
127.0.0.1 www.example.local
127.0.0.1 api.example.local
What can I be doing wrong?

Answer 1

The nginx container and the upstream server need to be on the same docker network.
Example:
Assuming the nginx container is exposed ports 443 on the bridge, create a docker network called nginx-network and join it to that network.
Assuming also the upstream server is a container called ‘mysite’, join that container to the nginx-network, nginx will then be able to resolve the dns ‘mysite’.