feat(env): Add SENTRY_BIND var (#512)

Closes #279, supercedes #306. This is much simpler and safer now that we have `nginx` in front of everything.

Thanks a lot @larsnystrom!

Author: BYK

.env

@@ -1,5 +1,8 @@
 COMPOSE_PROJECT_NAME=sentry_onpremise
 SENTRY_EVENT_RETENTION_DAYS=90
+# You can either use a port number or an IP:PORT combo for SENTRY_BIND
+# See https://docs.docker.com/compose/compose-file/#ports for more
+SENTRY_BIND=9000
 SENTRY_IMAGE=getsentry/sentry:latest
 SNUBA_IMAGE=getsentry/snuba:latest
 RELAY_IMAGE=getsentry/relay:latest

docker-compose.yml

@@ -190,7 +190,7 @@ services:
   nginx:
     << : *restart_policy
     ports:
-      - '9000:80/tcp'
+      - '$SENTRY_BIND:80/tcp'
     image: 'nginx:1.16'
     volumes:
       - type: bind