docker-compose: Rework comment style and document uploads.

Double-quote comments like we have in prod_settings_template.py seem
clearer, and it seems useful to have explicit documentation of the
uploads syntax.

Fixes #394.

Author: timabbott

docker-compose.yml

@@ -5,9 +5,9 @@ services:
     environment:
       POSTGRES_DB: "zulip"
       POSTGRES_USER: "zulip"
-      # Note that you need to do a manual `ALTER ROLE` query if you
-      # change this on a system after booting the postgres container
-      # the first time on a host.  Instructions are available in README.md.
+      ## Note that you need to do a manual `ALTER ROLE` query if you
+      ## change this on a system after booting the postgres container
+      ## the first time on a host.  Instructions are available in README.md.
       POSTGRES_PASSWORD: "REPLACE_WITH_SECURE_POSTGRES_PASSWORD"
     volumes:
       - "postgresql-14:/var/lib/postgresql/data:rw"
@@ -53,18 +53,18 @@ services:
     build:
       context: .
       args:
-        # Change these if you want to build zulip from a different repo/branch
+        ## Change these if you want to build zulip from a different repo/branch
         ZULIP_GIT_URL: https://github.com/zulip/zulip.git
         ZULIP_GIT_REF: "9.2"
-        # Set this up if you plan to use your own CA certificate bundle for building
+        ## Set this up if you plan to use your own CA certificate bundle for building
         # CUSTOM_CA_CERTIFICATES:
     ports:
       - "80:80"
       - "443:443"
     environment:
-      # See https://github.com/zulip/docker-zulip#configuration for
-      # details on this section and how to discover the many
-      # additional settings that are supported here.
+      ## See https://github.com/zulip/docker-zulip#configuration for
+      ## details on this section and how to discover the many
+      ## additional settings that are supported here.
       DB_HOST: "database"
       DB_HOST_PORT: "5432"
       DB_USER: "zulip"
@@ -73,8 +73,8 @@ services:
       SETTING_RABBITMQ_HOST: "rabbitmq"
       SETTING_REDIS_HOST: "redis"
       SECRETS_email_password: "123456789"
-      # These should match RABBITMQ_DEFAULT_PASS, POSTGRES_PASSWORD,
-      # MEMCACHED_PASSWORD, and REDIS_PASSWORD above.
+      ## These should match RABBITMQ_DEFAULT_PASS, POSTGRES_PASSWORD,
+      ## MEMCACHED_PASSWORD, and REDIS_PASSWORD above.
       SECRETS_rabbitmq_password: "REPLACE_WITH_SECURE_RABBITMQ_PASSWORD"
       SECRETS_postgres_password: "REPLACE_WITH_SECURE_POSTGRES_PASSWORD"
       SECRETS_memcached_password: "REPLACE_WITH_SECURE_MEMCACHED_PASSWORD"
@@ -85,17 +85,33 @@ services:
       SETTING_EMAIL_HOST: "" # e.g. smtp.example.com
       SETTING_EMAIL_HOST_USER: "[email protected]"
       SETTING_EMAIL_PORT: "587"
-      # It seems that the email server needs to use ssl or tls and can't be used without it
+      ## It seems that the email server needs to use ssl or tls and can't be used without it
       SETTING_EMAIL_USE_SSL: "False"
       SETTING_EMAIL_USE_TLS: "True"
       ZULIP_AUTH_BACKENDS: "EmailAuthBackend"
-      # Uncomment this when configuring the mobile push notifications service
+      ## Uncomment this when configuring the mobile push notifications service
       # SETTING_ZULIP_SERVICE_PUSH_NOTIFICATIONS: "True"
       # SETTING_ZULIP_SERVICE_SUBMIT_USAGE_STATISTICS: "True"
 
-      # If you're using a reverse proxy, you'll want to provide the
-      # comma-separated set of IP addresses to trust here.
+      ## If you're using a reverse proxy, you'll want to provide the
+      ## comma-separated set of IP addresses to trust here.
       # LOADBALANCER_IPS: "",
+
+      ## By default, files uploaded by users and profile pictures are
+      ## stored directly on the Zulip server. You can configure files
+      ## to be stored in Amazon S3 or a compatible data store
+      ## here. See docs at:
+      ##
+      ##   https://zulip.readthedocs.io/en/latest/production/upload-backends.html
+      ##
+      ## If you want to use the S3 backend, you must set
+      ## SETTINGS_LOCAL_UPLOADS_DIR to None as well as configuring the
+      ## other fields.
+      # SETTINGS_LOCAL_UPLOADS_DIR: "None"
+      # SETTINGS_S3_AUTH_UPLOADS_BUCKET: ""
+      # SETTINGS_S3_AVATAR_BUCKET: ""
+      # SETTINGS_S3_ENDPOINT_URL: "None"
+      # SETTINGS_S3_REGION: "None"
     volumes:
       - "zulip:/data:rw"
     ulimits: