Elasticsearch API is fully open by default and anyone can create (PUT method) or delete indices (DELETE method).
In a project at work, I was asked to install a fully redondant cluster, and among other things expose the API:
- over HTTP with no auth for GET method for developers
- over HTTPS with auth for any methods (PUT, DELETE, etc.) for Elastic admins
The Elastic cluster is orchestrated with Saltstack (I’ll publish the states later) and is made of 8 nodes, two of them act as clients (no master nor data role) and are only accessible from two HAproxy nodes (secured with iptables).
This is the HAproxy configuration, tested on RHEL7.
I intentionally used insecure-password for authentication over HTTPS, so you can basically copy and paste this configuration and test. Please use “password” when you’re ready to go in production.
global log graylog.example.org:10514 local0 log-send-hostname chroot /var/lib/haproxy user haproxy group haproxy daemon maxconn 4000 defaults log global mode http option httplog option dontlognull option redispatch retries 3 timeout client 35s timeout server 60s timeout connect 5s timeout http-keep-alive 10s listen stats :8080 stats enable stats uri / stats realm Haproxy\ Statistics stats auth admin:john_snuuuh backend elastic-backend-http-9200 mode http timeout connect 10s timeout server 30s balance roundrobin server selk01logger01prd-9200 selk01logger01prd.intranet.example.org:9200 weight 1 maxconn 512 check server selk01logger02prd-9200 selk01logger02prd.intranet.example.org:9200 weight 1 maxconn 512 check frontend elastic-frontend-http-80 bind *:80 mode http option forwardfor option http-server-close option http-pretend-keepalive acl ELASTIC_GET method GET use_backend elastic-backend-http-9200 if ELASTIC_GET userlist ELASTIC_ADMIN user elasticadmin insecure-password ThisShouldBeChanged frontend elastic-frontend-https-443 bind *:443 ssl crt /etc/ssl/certs/mycert.pem mode http option forwardfor option http-server-close option http-pretend-keepalive acl AUTH_E2SA http_auth(ELASTIC_ADMIN) http-request allow if AUTH_E2SA http-request deny default_backend elastic-backend-http-9200