--- sidebar_position: 4 --- # Nginx + Image Archive > DISCLAIMER! We make no claims or guarantees of this approach's security. If in > doubt, enlist the help of an expert and conduct proper audits. At a certain point, you may want others to have access to your instance of the OHIF Viewer and its medical imaging data. This post covers one of many potential setups that accomplish that. Please note, noticably absent is user account control. Do not use this recipe to host sensitive medical data on the open web. Depending on your company's policies, this may be an appropriate setup on an internal network when protected with a server's basic authentication. For a more robust setup, check out our [user account control recipe](./user-account-control.md) that builds on the lessons learned here. ## Overview Our two biggest hurdles when hosting our image archive and web client are: - Risks related to exposing our PACS to the netowrk - Cross-Origin Resource Sharing (CORS) requests ### Handling Web Requests We mittigate our first issue by allowing [Nginx][nginx] to handle incoming web requests. Nginx is open source software for web serving, reverse proxying, caching, and more. It's designed for maximum performance and stability -- allowing us to more reliably serve content than Orthanc's built-in server can. More specifically, we accomplish this by using a [`reverse proxy`](https://en.wikipedia.org/wiki/Reverse_proxy) to retrieve resources from our image archive (Orthanc), and when accessing its web admin. > A reverse proxy is a type of proxy server that retrieves resources on behalf > of a client from one or more servers. These resources are then returned to the > client, appearing as if they originated from the proxy server itself. ### CORS Issues Cross-Origin Resource Sharing (CORS) is a mechanism that uses HTTP headers to tell a browser which web applications have permission to access selected resources from a server at a different origin (domain, protocol, port). IE. By default, a Web App located at `http://my-website.com` can't access resources hosted at `http://not-my-website.com` We can solve this one of two ways: 1. Have our Image Archive located at the same domain as our Web App 2. Add appropriate `Access-Control-Allow-*` HTTP headers **This solution uses the first approach.** You can read more about CORS in this Medium article: [Understanding CORS][understanding-cors] ### Diagram This setup allows us to create a setup similar to the one pictured below: ![nginX](../../assets/img/nginx-image-archive.png) - All web requests are routed through `nginx` on our `OpenResty` image - `/pacs` is a reverse proxy for `orthanc`'s `DICOM Web` endpoints - `/pacs-admin` is a reverse proxy for `orthanc`'s Web Admin - All static resources for OHIF Viewer are served up by `nginx` when a matching route for that resource is requested ## Getting Started ### Requirements - Docker - [Docker for Mac](https://docs.docker.com/docker-for-mac/) - [Docker for Windows](https://docs.docker.com/docker-for-windows/) _Not sure if you have `docker` installed already? Try running `docker --version` in command prompt or terminal_ ### Setup _Spin Things Up_ - Navigate to `/docker/OpenResty-Orthanc` in your shell - Run `docker-compose up` _Upload Your First Study_ - Navigate to `http://127.0.0.1/pacs-admin` - From the top right, select "Upload" - Click "Select files to upload..." (DICOM) - Click "Start the upload" - Navigate back to `http://127.0.0.1/` to view your studies in the Study List ### Troubleshooting _Exit code 137_ This means Docker ran out of memory. Open Docker Desktop, go to the `advanced` tab, and increase the amount of Memory available. _Cannot create container for service X_ Use this one with caution: `docker system prune` _X is already running_ Stop running all containers: - Win: `docker ps -a -q | ForEach { docker stop $_ }` - Linux: `docker stop $(docker ps -a -q)` ### Configuration After verifying that everything runs with default configuration values, you will likely want to update: - The domain: `http://127.0.0.1` #### OHIF Viewer The OHIF Viewer's configuration is imported from a static `.js` file. The configuration we use is set to a specific file when we build the viewer, and determined by the env variable: `APP_CONFIG`. You can see where we set its value in the `dockerfile` for this solution: `ENV APP_CONFIG=config/docker_openresty-orthanc.js` You can find the configuration we're using here: `/public/config/docker_openresty-orthanc.js` To rebuild the `webapp` image created by our `dockerfile` after updating the Viewer's configuration, you can run: - `docker-compose build` OR - `docker-compose up --build` #### Other All other files are found in: `/docker/OpenResty-Orthanc/` | Service | Configuration | Docs | | ----------------- | --------------------------------- | ------------------------------------------- | | OHIF Viewer | [dockerfile][dockerfile] | You're reading them now! | | OpenResty (Nginx) | [`/nginx.conf`][config-nginx] | [lua-resty-openidc][lua-resty-openidc-docs] | | Orthanc | [`/orthanc.json`][config-orthanc] | [Here][orthanc-docs] | ## Next Steps ### Deploying to Production While these configuration and docker-compose files model an environment suitable for production, they are not easy to deploy "as is". You can either: - Manually recreate this environment and deploy built application files **OR** - Deploy to a cloud kubernetes provider like [Digital Ocean](https://www.digitalocean.com/products/kubernetes/) **OR** - [See a full list of cloud providers here](https://landscape.cncf.io/category=cloud&format=card-mode&grouping=category) - Find and follow your preferred provider's guide on setting up [swarms and stacks](https://docs.docker.com/get-started/) ### Adding SSL Adding SSL registration and renewal for your domain with Let's Encrypt that terminates at Nginx is an incredibly important step toward securing your data. Here are some resources, specific to this setup, that may be helpful: - [lua-resty-auto-ssl](https://github.com/GUI/lua-resty-auto-ssl) - [Let's Encrypt + Nginx](https://www.nginx.com/blog/using-free-ssltls-certificates-from-lets-encrypt-with-nginx/) While we terminate SSL at Nginx, it may be worth using self signed certificates for communication between services. - [SSL Termination for TCP Upstream Servers](https://docs.nginx.com/nginx/admin-guide/security-controls/terminating-ssl-tcp/) ### Use PostgresSQL w/ Orthanc Orthanc can handle a large amount of data and requests, but if you find that requests start to slow as you add more and more studies, you may want to configure your Orthanc instance to use PostgresSQL. Instructions on how to do that can be found in the [`Orthanc Server Book`](http://book.orthanc-server.com/users/docker.html), under "PostgreSQL and Orthanc inside Docker" ### Improving This Guide Here are some improvements this guide would benefit from, and that we would be more than happy to accept Pull Requests for: - SSL Support - Complete configuration with `.env` file (or something similar) - Any security issues - One-click deploy to a cloud provider ## Resources ### Misc. Helpful Commands _Check if `nginx.conf` is valid:_ ```bash docker run --rm -t -a stdout --name my-openresty -v $PWD/config/:/usr/local/openresty/nginx/conf/:ro openresty/openresty:alpine-fat openresty -c /usr/local/openresty/nginx/conf/nginx.conf -t ``` _Interact w/ running container:_ `docker exec -it CONTAINER_NAME bash` _List running containers:_ `docker ps` ### Referenced Articles For more documentation on the software we've chosen to use, you may find the following resources helpful: - [Orthanc for Docker](http://book.orthanc-server.com/users/docker.html) - [OpenResty Guide](http://www.staticshin.com/programming/definitely-an-open-resty-guide/) - [Lua Ngx API](https://openresty-reference.readthedocs.io/en/latest/Lua_Nginx_API/) For a different take on this setup, check out the repositories our community members put together: - [mjstealey/ohif-orthanc-dimse-docker](https://github.com/mjstealey/ohif-orthanc-dimse-docker) - [trypag/ohif-orthanc-postgres-docker](https://github.com/trypag/ohif-orthanc-postgres-docker) [nginx]: https://www.nginx.com/resources/glossary/nginx/ [understanding-cors]: https://medium.com/@baphemot/understanding-cors-18ad6b478e2b [orthanc-docs]: http://book.orthanc-server.com/users/configuration.html#configuration [lua-resty-openidc-docs]: https://github.com/zmartzone/lua-resty-openidc [dockerfile]: https://github.com/OHIF/Viewers/blob/master/platform/viewer/.recipes/OpenResty-Orthanc/dockerfile [config-nginx]: https://github.com/OHIF/Viewers/blob/master/platform/viewer/.recipes/OpenResty-Orthanc/config/nginx.conf [config-orthanc]: https://github.com/OHIF/Viewers/blob/master/platform/viewer/.recipes/OpenResty-Orthanc/config/orthanc.json