it seem that mattermost is running.
i got the following prompt after ./platform
root@mattermost:/opt/mattermost/bin# ./platform
[2016/08/10 08:52:49 CEST] [INFO] Loaded system translations for 'en' from '/opt/mattermost/i18n/en.json'
[2016/08/10 08:52:49 CEST] [INFO] Current version is 3.2.0 (3.2.0/Thu Jul 14 16:27:27 UTC 2016/ab52700aaa76a5623de23cd0156f5dbd9a24e264/none)
[2016/08/10 08:52:49 CEST] [INFO] Enterprise Enabled: false
[2016/08/10 08:52:49 CEST] [INFO] Current working directory is /opt/mattermost/bin
[2016/08/10 08:52:49 CEST] [INFO] Loaded config file from /opt/mattermost/config/config.json
[2016/08/10 08:52:49 CEST] [INFO] Server is initializing...
[2016/08/10 08:52:49 CEST] [INFO] Pinging sql master database
[2016/08/10 08:52:49 CEST] [INFO] Pinging sql replica-0 database
[2016/08/10 08:52:49 CEST] [DEBG] Deleting any unused pre-release features
[2016/08/10 08:52:49 CEST] [DEBG] Initializing user api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing team api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing channel api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing post api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing web socket api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing file api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing command api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing admin api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing general api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing oauth api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing webhook api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing preference api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing license api routes
[2016/08/10 08:52:49 CEST] [DEBG] Initializing emoji api routes
[2016/08/10 08:52:49 CEST] [DEBG] Parsing server templates at /opt/mattermost/templates/
[2016/08/10 08:52:49 CEST] [DEBG] Initializing web routes
[2016/08/10 08:52:49 CEST] [DEBG] Using client directory at /opt/mattermost/webapp/dist/
[2016/08/10 08:52:49 CEST] [INFO] Starting Server...
[2016/08/10 08:52:49 CEST] [INFO] Server is listening on :8065
[2016/08/10 08:52:49 CEST] [INFO] RateLimiter is enabled
thats why i'm so confused about the error 502 at nginx