Nginx load balancer show incomplete HTTPS pages - ssl

Question

I have to configure an NGINX server in order to load balance 2 ore more https websites.
I wrote this code:
user nginx;
#worker_processes 1;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA';
ssl_prefer_server_ciphers on;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
# sendfile on;
#tcp_nopush on;
# keepalive_timeout 65;
upstream servers_alpha {
least_conn;
#server 10.200.0.43:801 max_fails=3 fail_timeout=30s;
server 10.200.0.43:443 max_fails=3 fail_timeout=30s;
#server 10.200.0.70:801 max_fails=3 fail_timeout=30s;
server 10.200.0.141:443 max_fails=3 fail_timeout=30s;
}
server {
#listen 80;
listen 443 ssl;
#ssl on;
ssl_certificate /etc/nginx/ssl/proxy1/server.crt;
ssl_certificate_key /etc/nginx/ssl/proxy1/server.key;
server_name proxy1;
location / {
proxy_pass https://servers_alpha;
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-Proto $scheme;
}
location /nginx_status {
stub_status on;
access_log off;
allow 127.0.0.1;
# allow 10.200.0.111;
allow 10.5.1.101;
deny all;
}
}
#location / {
# root /usr/share/nginx/html;
# index index.html index.htm;
# }
}
The 2 servers I'm using in this example are:
10.200.0.43 --> Spacewalk
10.200.0.141 --> Ansible
If I browse those sites directly there are no issues, the sites are fine and browsable.
If I pass through NGINX the sites are incomplete and not working: useless, unusable, as you can see in the images:
Ansible 1
Ansible 2
Spacewalk
This is the access.log:
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET / HTTP/1.1" 302 216 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /rhn/Login.do HTTP/1.1" 404 3360 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/css/bootstrap.min.css HTTP/1.1" 404 5086 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/api/api.css?v=3.0.2 HTTP/1.1" 200 7442 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/css/default.css HTTP/1.1" 200 1132 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/csrf.js HTTP/1.1" 200 1832 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/css/prettify.css HTTP/1.1" 404 5086 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/bootstrap.min.js HTTP/1.1" 200 36816 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/prettify-min.js HTTP/1.1" 200 13632 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/default.js HTTP/1.1" 200 1760 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/api/api.js?v=3.0.2 HTTP/1.1" 200 3145 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/assets/main_menu_logo.png HTTP/1.1" 200 6359 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/ajax-form.js HTTP/1.1" 404 5092 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/jquery-1.11.3.min.js HTTP/1.1" 200 95957 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/rest_framework/js/ajax-form.js HTTP/1.1" 404 5092 "https://10.200.0.69/rhn/Login.do" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
10.5.1.101 - - [04/Sep/2018:17:38:36 +0200] "GET /static/assets/favicon.ico?v=3.0.2 HTTP/1.1" 200 15086 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0" "-"
While the error.log:
2018/09/04 17:38:36 [warn] 17259#17259: *243 an upstream response is buffered to a temporary file /var/cache/nginx/proxy_temp/2/00/0000000002 while reading upstream, client: 10.5.1.101, server: proxy1, request: "GET /static/rest_framework/js/jquery-1.11.3.min.js HTTP/1.1", upstream: "https://10.200.0.141:443/static/rest_framework/js/jquery-1.11.3.min.js", host: "10.200.0.69", referrer: "https://10.200.0.69/rhn/Login.do"`
Can you please tell me what I'm doing wrong?
ps: If I redirect on http it works fine