502 error code on nginx reverse proxy to docker container

Question

I have run a docker container with nextcloud image (from here https://hub.docker.com/_/nextcloud/) with this script:

docker run \
--rm \
--detach \
--publish 54002:80 \
--name cloud.example.com \
--volume /srv/cloud.example.com/:/var/www/html \
nextcloud

And I Have made a reverse proxy with nginx:

server {
        listen *:80;
        server_name cloud.example.com;
        proxy_set_header Host cloud.example.com;
        location / {
        rewrite ^(.*)$ https://cloud.example.com$1 permanent;
        }
}

server {
        listen *:443 ssl http2;
        server_name     cloud.example.com;
        proxy_set_header Host cloud.example.com;
        set $service_port 54002;
        set $service_ip 192.168.2.33;
        ssl_certificate         /etc/letsencrypt/live/cloud.example.com/fullchain.pem;
        ssl_certificate_key             /etc/letsencrypt/live/cloud.example.com/privkey.pem;

        add_header Strict-Transport-Security "max-age=15552000; includeSubDomains" always;
        add_header X-Content-Type-Options nosniff;
        add_header X-Frame-Options "SAMEORIGIN";
        add_header X-XSS-Protection "1; mode=block";
        add_header X-Robots-Tag none;
        add_header X-Download-Options noopen;
        add_header X-Permitted-Cross-Domain-Policies none;

        location / {
                proxy_pass http://$service_ip:$service_port;
        }
}

And I get 502 error code. I have checked from local network http://server_ip:54002, it works fine, also only http site with proxy also works! Http Nginx config that works:

server {
        set $service_port 54002;
        set $service_ip 192.168.2.33;
        set $domain_name cloud.example.com;

        listen *:80;
        server_name $domain_name;

        proxy_set_header Host $domain_name;

        location / {
                proxy_pass http://$service_ip:$service_port;
        }
}

What is wrong with my https config?

score 0 · Accepted Answer · answered Jul 11 '17 at 10:22

After struggling a lot of hours with this problem I finally found an error in my server config. With nginx everything is fine, but I forgot to allow 443 port in ufw. I erroneously decided that rule "Nginx HTTP" is sufficient for both http and https connections, but in fact only 80/tcp port was open, so I entered ufw allow 443/tcp and all errors gone! @alexus and others excuse me for wasting yours time!

502 error code on nginx reverse proxy to docker container

1 Answers1