This repository contains setup for a backend component of the AAS WorldWide Telescope web services.
In particular, the core WWT website runs an nginx web server to handle miscellaneous redirections and serve certain static files. The responsibilities of this server are a hodgepodge based on the website's historical URL routes, since we route incoming requests to different backends using URL path routing in our Azure Application Gateway frontend.
This server also has vhosts configured to serve up a few special-purpose
domains with extremely limited functionality, e.g. redirecting the old
forum.worldwidetelescope.org to wwt-forum.org.
This isn't really software that "install" yourself. The output artifact of this repository is a Docker image that you obtain with the command:
docker build -t aasworldwidetelescope/nginx-core:latest .
You can then run the server locally with a command such as:
docker run --rm -p 8888:80 aasworldwidetelescope/nginx-core:latest
but you'll need to manually telnet in HTTP requests to get anything to work due to the vhost configuration. E.g.,
$ telnet localhost 8888
GET /support/wwtsetup-latest.msi HTTP/1.1
Host: worldwidetelescope.org
HTTP/1.1 302 Moved Temporarily
Server: nginx/1.16.1
...
The main purpose of this pipeline is to automate the build and publication of
this image through the azure-pipelines.yml file. The image ultimately
emerges as
aasworldwidetelescope/nginx-core.
A webhook is configured there to update the running service on Azure.
The live servers are run as virtual hosts as Azure App Services behind an
Azure Application Gateway. Because they are run as vhosts, each request must
be passed the correct HTTP Host header, pointing to something like
wwtnginxcore-prod.azurewebsites.net. However, that means that if this server
issues redirects, by default they will point to the App Service domain name,
not the actual worldwidetelescope.org domain. App Gateway doesn't seem to
provide a facility for us to correctly rewrite any outgoing Location headers
from the App Service, so we instead provide a mechanism to make sure that the
emitted URLs point to the intended domain. If the environment variable
PUBLIC_FACING_DOMAIN_NAME is set, redirection URLs will be rooted
accordingly, with the scheme determined from a X-Forwarded-Proto HTTP header
if available.
Contributions are welcome! See the WorldWide Telescope contributors’ guide for applicable information. We use a standard workflow with issues and pull requests. All participants in this repository and the WWT communities must abide by the WWT Code of Conduct.
The files in this repository are copyright the .NET Foundation, licensed under the MIT License.
wwt-nginx-core is part of the AAS WorldWide Telescope system, a
.NET Foundation project managed by the non-profit
American Astronomical Society (AAS). Work on WWT has been supported by the
AAS, the US National Science Foundation (grants 1550701 and 1642446),
the Gordon and Betty Moore Foundation, and Microsoft.