+Expose a directory inside the host to the container.
+
+#### links:
+```
+links:
+ - link:
+ name: postgres
+ alias: postgres
+```
+
+Links another container to the current container. This will add `--link postgres:postgres`
+to the options when running the container.
+
+#### environment variables:
+
+Setting environment variables to the current container.
+
+```
+# app.yml
+
+env:
+ DISCOURSE_DB_HOST: some-host
+ DISCOURSE_DB_NAME: {{config}}_discourse
+```
+
+The above will add `-e DISCOURSE_DB_HOST=some-host -e DISCOURSE_DB_NAME=app_discourse` to the options when running the container.
+
+#### labels:
+```
+# app.yml
+
+labels:
+ monitor: 'true'
+ app_name: {{config}}_discourse
+```
+
+Add labels to the current container. The above will add `--l monitor=true -l app_name=dev_discourse` to the options
+when running the container
+
+### Upgrading Discourse
+
+The Docker setup gives you multiple upgrade options:
+
+1. Use the front end at http://yoursite.com/admin/upgrade to upgrade an already running image.
+
+2. Create a new base image manually by running:
+ - `./launcher rebuild my_image`
+
+### Single Container vs. Multiple Container
+
+The samples directory contains a standalone template. This template bundles all of the software required to run Discourse into a single container. The advantage is that it is easy.
+
+The multiple container configuration setup is far more flexible and robust, however it is also more complicated to set up. A multiple container setup allows you to:
+
+- Minimize downtime when upgrading to new versions of Discourse. You can bootstrap new web processes while your site is running and only after it is built, switch the new image in.
+- Scale your forum to multiple servers.
+- Add servers for redundancy.
+- Have some required services (e.g. the database) run on beefier hardware.
+
+If you want a multiple container setup, see the `data.yml` and `web_only.yml` templates in the samples directory. To ease this process, `launcher` will inject an env var called `DISCOURSE_HOST_IP` which will be available inside the image.
+
+WARNING: In a multiple container configuration, *make sure* you setup iptables or some other firewall to protect various ports (for postgres/redis).
+On Ubuntu, install the `ufw` or `iptables-persistent` package to manage firewall rules.
+
+### Email
+
+For a Discourse instance to function properly Email must be set up. Use the `SMTP_URL` env var to set your SMTP address, see sample templates for an example. The Docker image does not contain postfix, exim or another MTA, it was omitted because it is very tricky to set up correctly.
+
+### Troubleshooting
+
+View the container logs: `./launcher logs my_container`
+
+Spawn a shell inside your container using `./launcher enter my_container`. This is the most foolproof method if you have host root access.
+
+If you see network errors trying to retrieve code from `github.com` or `rubygems.org` try again - sometimes there are temporary interruptions and a retry is all it takes.
+
+Behind a proxy network with no direct access to the Internet? Add proxy information to the container environment by adding to the existing `env` block in the `container.yml` file:
+
+```yaml
+env:
+ …existing entries…
+ HTTP_PROXY: http://proxyserver:port/
+ http_proxy: http://proxyserver:port/
+ HTTPS_PROXY: http://proxyserver:port/
+ https_proxy: http://proxyserver:port/
+```