It should be fine. A regular browser gives me this:
{"code":404,"message":"HTTP 404 Not Found"}
From the appliance itself:
ubuntu@graylog:~$
ubuntu@graylog:~$ curl -v -XGET https://api.graylog.com
* Rebuilt URL to: https://api.graylog.com/
* Hostname was NOT found in DNS cache
* Trying 23.23.209.130...
* Connected to api.graylog.com (23.23.209.130) port 443 (#0)
* successfully set certificate verify locations:
* CAfile: none
CApath: /etc/ssl/certs
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Server key exchange (12):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using ECDHE-RSA-AES128-GCM-SHA256
* Server certificate:
* subject: CN=api.graylog.com
* start date: 2018-02-22 23:36:53 GMT
* expire date: 2018-05-23 23:36:53 GMT
* subjectAltName: api.graylog.com matched
* issuer: C=US; O=Let's Encrypt; CN=Let's Encrypt Authority X3
* SSL certificate verify ok.
> GET / HTTP/1.1
> User-Agent: curl/7.35.0
> Host: api.graylog.com
> Accept: */*
>
< HTTP/1.1 404 Not Found
* Server Cowboy is not blacklisted
< Server: Cowboy
< Connection: keep-alive
< Date: Wed, 28 Feb 2018 16:06:24 GMT
< Content-Type: application/json
< Content-Length: 43
< Via: 1.1 vegur
<
* Connection #0 to host api.graylog.com left intact
{"code":404,"message":"HTTP 404 Not Found"}