NginX reverse proxy for Kibana over Docker

You are connecting all the containers in this config via container network. Look at the environment variables set in the Kibana config:

      ELASTICSEARCH_URL: http://elasticsearch_1:9200

Here you can see, that the hostname of the other container running ElasticSearch is elasticsearch_1. In a similar manner, the hostname of the container running Kibana woud be kibana. These hostnames are only availiable inside the container network.

So in your Nginx config, you’ll have to proxy_pass to http://kibana:5601 instead of localhost.