Merge branch 'master' of https://github.com/sharelatex/sharelatex-docker-image

The available configuration parameters are:

* `SHARELATEX_SITE_URL`: Where your instance of ShareLaTeX is publically available.

This is used in public links, and when connecting over websockets, so much be

This is used in public links, and when connecting over websockets, so must be

configured correctly!

* `SHARELATEX_ADMIN_EMAIL`: The email address where users can reach the person who runs the site.

* `SHARELATEX_APP_NAME`: The name to display when talking about the running app. Defaults to 'ShareLaTex (Community Edition)'.

*Please make sure to back up all Mongo, Redis and on-disk data before upgrading.*

Stop and remove the currently running ShareLaTeX container:

#### Migrations

Data stored in Mongodb will be automatically migrated to the latest schemea when upgrading docker releases. **This can make downgrades impossible.** One recommended technique is to test the migration first. This can be done by copying the mongodb database and doing a test run against the copied data.

```

db.copyDatabase(sharelatex,sharelatex-copy)

# start the container up pointing at the new db

--env SHARELATEX_MONGO_URL=mongodb://dockerhost/sharelatex-copy

```

#### Upgrade process

To use the new docker container stop and remove the currently running ShareLaTeX container:

```

$ docker stop sharelatex

	gzip on;

	gzip_disable "msie6";

	client_max_body_size 50m;

	# gzip_vary on;

	# gzip_proxied any;

	# gzip_comp_level 6;