Nginx Load Balancing HTTPs cluster - nginx

Question

I watn to use Nginx as load balancer for Consul cluster. The Consul cluster is reachable only with TLS.
Here I've tried to reverse proxy a single Consul server to check if the TLS certificates are working
server {
listen 80;
listen [::]:80;
location /consul/ {
resolver 127.0.0.1;
proxy_pass https://core-consul-server-1-dev.company.io:8500;
sub_filter_types text/css application/javascript;
sub_filter_once off;
sub_filter /v1/ /consul_v1/;
proxy_ssl_certificate /etc/nginx/certs/agent.crt;
proxy_ssl_certificate_key /etc/nginx/certs/agent.key;
proxy_ssl_trusted_certificate /etc/nginx/certs/ca.crt;
proxy_ssl_verify on;
proxy_ssl_verify_depth 4;
}
}
this configuration working fine and I can call it with
curl http://core-proxy-server-1-dev.company.io/consul/consul_v1/agent/members
Now I've tried to do an upstream like this:
upstream consul {
server core-consul-server-1-dev.company.io:8500;
server core-consul-server-2-dev.company.io:8500;
}
server {
listen 80;
listen [::]:80;
location /consul/ {
resolver 127.0.0.1;
proxy_pass https://consul;
sub_filter_types text/css application/javascript;
sub_filter_once off;
sub_filter /v1/ /consul_v1/;
proxy_ssl_certificate /etc/nginx/certs/agent.crt;
proxy_ssl_certificate_key /etc/nginx/certs/agent.key;
proxy_ssl_trusted_certificate /etc/nginx/certs/ca.crt;
proxy_ssl_verify on;
proxy_ssl_verify_depth 4;
}
}
when calling the same curl command as before, I get the following error:
2021/04/20 08:38:59 [debug] 3364#3364: *1 X509_check_host(): no match
2021/04/20 08:38:59 [error] 3364#3364: *1 upstream SSL certificate does not match "consul" while SSL handshaking to upstream, client: 10.10.xx.xxx, server: , request: "GET /consul/consul_v1/agent/members HTTP/1.1", upstream: "https://10.10.yy.yyy:8500/consul/consul_v1/agent/members", host: "core-proxy-server-1-dev.company.io"
Then I've tried like this:
upstream consul_1 {
server core-consul-server-1-dev.company.io:8500;
}
upstream consul_2 {
server core-consul-server-2-dev.company.io:8500;
}
map $http_host $backend {
core-consul-server-1-dev.company.io consul_1;
core-consul-server-2-dev.company.io consul_2;
}
server {
listen 80;
listen [::]:80;
location /consul/ {
resolver 127.0.0.1;
proxy_pass https://$backend;
sub_filter_types text/css application/javascript;
sub_filter_once off;
sub_filter /v1/ /consul_v1/;
proxy_ssl_certificate /etc/nginx/certs/agent.crt;
proxy_ssl_certificate_key /etc/nginx/certs/agent.key;
proxy_ssl_trusted_certificate /etc/nginx/certs/ca.crt;
proxy_ssl_verify on;
proxy_ssl_verify_depth 4;
}
}
but also no luck;
2021/04/20 08:45:05 [error] 3588#3588: *1 invalid URL prefix in "https://", client: 10.10.xx.xxx, server: , request: "GET /consul/consul_v1/agent/members HTTP/1.1", host: "core-proxy-server-1-dev.company.io"
any ideas? can someone please help me with one?

Answer 1

I figured it out.
in this variation:
upstream consul {
server core-consul-server-1-dev.company.io:8500;
server core-consul-server-2-dev.company.io:8500;
}
server {
listen 80;
listen [::]:80;
location /consul/ {
resolver 127.0.0.1;
proxy_pass https://consul;
sub_filter_types text/css application/javascript;
sub_filter_once off;
sub_filter /v1/ /consul_v1/;
proxy_ssl_certificate /etc/nginx/certs/agent.crt;
proxy_ssl_certificate_key /etc/nginx/certs/agent.key;
proxy_ssl_trusted_certificate /etc/nginx/certs/ca.crt;
proxy_ssl_verify on;
proxy_ssl_verify_depth 4;
}
}
the upstream name consul should also match the alt_names I defined in my certificate. so changing the configuration to the one below did the trick:
upstream core-consul-server-1-dev.company.io{
server core-consul-server-1-dev.company.io:8500;
server core-consul-server-2-dev.company.io:8500;
}
server {
listen 80;
listen [::]:80;
location /consul/ {
resolver 127.0.0.1;
proxy_pass https://core-consul-server-1-dev.company.io;
sub_filter_types text/css application/javascript;
sub_filter_once off;
sub_filter /v1/ /consul_v1/;
proxy_ssl_certificate /etc/nginx/certs/agent.crt;
proxy_ssl_certificate_key /etc/nginx/certs/agent.key;
proxy_ssl_trusted_certificate /etc/nginx/certs/ca.crt;
proxy_ssl_verify on;
proxy_ssl_verify_depth 4;
}
}
I should just later add a general name in alt_names so I can reference the stream as
core-consul-server-dev.company.io