Load balancing docker swarm using Ha Proxy
If you get a 503 Service Not Available, then your health check fails.
From your configuration, HAProxy will use OPTIONS http://10.10.0.12:8443/ which will fail: your backend accept HTTPS connections. To fix that, tell HAProxy to use HTTPS:
server swarm 10.10.0.12:8443 check inter 5000 ssl verify noneNote: you can enable the stat page with
listen haproxy_admin bind 127.0.0.1:22002 mode http stats enable stats uri /That should help you debug further issues.
Edit:
The stat page shows L7STS/404, that's the http code HAProxy gets. HAProxy currently checks https://10.10.0.12:8443/ while you test https://10.10.0.12:8443/docs/index.html. Perhaps you should use this url in your check:
option httpchk OPTIONS /docs/index.html