Errror 503, HAProxy issue translating services across additional proxies, Docker, and LXD - linux

Question

I do believe I am most likely having issues with my HAProxy file, but I am unsure. I have previously used this same config file to access other services in containers, as well as other services on other loadbalancers, as well as apache systems, and now I am unable to do so.
I do not believe that the other service is to blame, as they are native snap installs.
HAProxy status URI shows the status as L7STS/502, and attempting to load the pages for the port show as 503.
Before, a page was loading, but it was Nextcloud, and so I went into the Gitlab config.rb file, and changed the Default Port for NGinx from 80 to 8800, and ran the gitlab-ctl reconfigure command to rebuild Git onto the other port, and made the correction appropriately inside of HAProxy as well.
Other services that are not behind a proxy of any kind are loading just fine, and docker container services are not loading appropriately either, showing the same 503 error, which leads me further to believe its my HAProxy config file.
Here is a HAProxy Config File:
global
log 127.0.0.1 syslog
maxconn 1000
user haproxy
group haproxy
daemon
defaults
log global
mode http
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
option contstats
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout check 10s
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http
###########################################
#
# HAProxy Stats page
#
###########################################
listen stats
bind *:9090
mode http
maxconn 10
stats enable
stats hide-version
stats realm Haproxy\ Statistics
stats uri /
stats auth -----:-----
###########################################
#
# Front end for all
#
###########################################
frontend ALL
bind *:80
mode http
# Define path for lets encrypt
acl is_letsencrypt path_beg -i /.well-known/acme-challenge/
use_backend letsencrypt if is_letsencrypt
# Define hosts
acl host_horizon hdr(host) -i horizon.eduarmor.com
acl host_eduarmor hdr(host) -i www.eduarmor.com
acl host_nextcloud hdr(host) -i nextcloud.eduarmor.com
acl host_git hdr(host) -i git.eduarmor.com
acl host_minecraft hdr(host) -i mine.eduarmor.com
acl host_sugar hdr(host) -i sugar.eduarmor.com
acl host_maas hdr(host) -i maas.eduarmor.com
acl host_rocketchat hdr(host) -i rocketchat.eduarmor.com
acl host_hive hdr(host) -i hive.eduarmor.com
# Direct hosts to backend
use_backend horizon if host_horizon
use_backend eduarmor if host_eduarmor
use_backend nextcloud if host_nextcloud
use_backend git if host_git
use_backend minecraft if host_minecraft
use_backend sugar if host_sugar
use_backend maas if host_maas
use_backend rocketchat if host_rocketchat
use_backend hive if host_hive
###########################################
#
# Back end letsencrypt
#
###########################################
backend letsencrypt
server letsencrypt 127.0.0.1:8888
###########################################
#
# Back end for Horizon
#
###########################################
backend horizon
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.30:80 check
# server server2 0.0.0.0:80 check
###########################################
#
# Back end for EduArmor
#
###########################################
backend eduarmor
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.59:80 check
# server server2 0.0.0.0:80 check
##########################################
#
# Back end for Nextcloud
#
##########################################
backend nextcloud
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:80 check
##########################################
#
# Back end, Gitlab
#
##########################################
backend git
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:8800 check
##########################################
#
# Back end, Minecraft
#
##########################################
backend minecraft
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:25565 check
##########################################
#
# Back end, PHPSugar
#
##########################################
backend sugar
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:80 check
##########################################
#
# Back End, MAAS
#
##########################################
backend maas
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.100:5240 check
##########################################
#
# Back end for Rocketchat
#
##########################################
backend rocketchat
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:3000 check
server server2 10.0.0.102:3000 check
##########################################
#
# Back end for The Hive
#
##########################################
backend hive
balance roundrobin
# option httpchk GET /check
option httpchk GET /
# http-check expect rstring ^UP$
default-server inter 3s fall 3 rise 2
server server1 10.0.0.101:9000 check
server server2 10.0.0.102:9000 check
I would greatly appreciate any advice or insight into solving this problem, as well as any additional resources you may have on best practices, especially including configuring for SSL/TLS usage.

Answer 1

The solution was to comment out the option httpchk GET / comment, specifically for thehive backend, as well as shift away from using docker-compose to docker-swarm, which also substantially increased my knowledge as a whole of how docker works. The combination of issues from docker-compose combined with the / CHK was causing HAProxy to read the services as down, and returning a 503 error, which also meant it would never serve the services.
I would like to thank the anonymous person who volunteered their time to teach me docker-swarm and CI/CD processes tonight. I am much better for it than I would ever have been with being just spoon fed the answer, and I thank you so much for it, so do a lot of homeless veterans.