Thanks for your response. I am following quick start guide and didn't change something significant. I think the original problem is solved by changing the host from http to https but another problem comes up and it is connection refused problem.
2020-01-23T14:00:36.042Z ERROR pipeline/output.go:100 Failed to connect to backoff(elasticsearch(https://quickstart-es-http:9200)): Get https://quickstart-es-http:9200: dial tcp 23.217.138.110:9200: connect: connection refused
2020-01-23T14:00:36.042Z INFO pipeline/output.go:93 Attempting to reconnect to backoff(elasticsearch(https://quickstart-es-http:9200)) with 3 reconnect attempt(s)
2020-01-23T14:00:36.042Z INFO [publisher] pipeline/retry.go:196 retryer: send unwait-signal to consumer
2020-01-23T14:00:36.042Z INFO [publisher] pipeline/retry.go:198 done
2020-01-23T14:00:36.042Z INFO [publisher] pipeline/retry.go:173 retryer: send wait signal to consumer
2020-01-23T14:00:36.042Z INFO [publisher] pipeline/retry.go:175 done
The solutions out there are referring to modifying network.host field in elasticsearch yaml file. what do you suggest?