Django subdomain rewrite using uwsgi on Google Cloud Run

Question

I am moving a Django site to GCP and using Google Cloud Run for the first time. The experience is great. I was also very pleased with the domain mapping feature, but I am having trouble with forwarding the www subdomain to the naked domain URL. For consistent page analytics, I would like visitors who browse to https://www.mycooldomainname.com to be 301 redirected to https://mycooldomainname.com (real domain redacted)

DNS setup

I added the naked and www subdomain to Cloud Run custom domains:

And added the required A, AAA and CNAME records at my registrar:

After everything propagated I can visit my site at https://mycooldomainname.com and https://www.mycooldomainname.com, but how can I configure the forwarding/rewriting?

From other posts I have read where people achieved this with Google Cloud DNS, it looks like they used an alias to do the forwarding.

In this case, I am trying to do the forwarding via uwsgi:

Webserver setup

The django app is served via uwsgi with this configuration - notice the redirect rule:

[uwsgi]
plugins-dir = /usr/lib/uwsgi/plugins
plugins = router_uwsgi
route-uri = ^(.*)\/\/www\.(.*)$ redirect-301:$1//$2
hook-master-start = unix_signal:15 gracefully_kill_them_all
http-socket = 0.0.0.0:8000
cheaper = 1
cheaper-algo = backlog
workers = 3
master = true
enable-threads = true
threads = 12
offload-threads = 12
harakiri = 300
http-harakiri = 300
logformat = %(var.HTTP_X_REAL_IP) - %(user) [%(ltime)] "%(method) %(uri) %(proto)" %(status) %(size) "%(referer)" "%(uagent)\" %(msecs)ms
static-map = /=webroot
static-gzip-all = true
module = app.wsgi

The actual redirect works fine on other parts of the url, for example, if I include the following redirect test rule:

route-uri = ^(.*)est(.*)$ redirect-301:$1ust$2

browsing to https://www.mycooldomainname.com/test/ correctly redirects to https://www.mycooldomainname.com/tust/

So at this point I'm not sure if there is a GCP limitation on redirecting parts of a verified domain or my regex is wrong.

Answer 1

Thanks for all the advice! Here is what I learned:

1. DNS records can not be used for redirecting especially if the CNAME of a subdomain is used by GCP
2. Google Cloud Run does not limit URL redirecting in any way
3. uWSGI has powerful features, but they are hard to discover
4. The following redirect rule worked for me:

[uwsgi]
plugins-dir = /usr/lib/uwsgi/plugins
plugins = router_uwsgi
route-host = ^www.mycooldomainname.com$ redirect-permanent:https://mycooldomainname.com${REQUEST_URI}

And I needed to install the following in my base image to get the internal rewriting and plugins to be available:

FROM $PYTHON_IMAGE as base 

RUN apt-get update \
    && \
    apt-get install --no-install-recommends -y \
    libpcre3-dev zlib1g-dev \
    uwsgi-core \
    && \
    apt-get clean && rm -rf /var/lib/apt/lists/*

Answer 2

I believe you should be able to configure this using Google Load Balancer.

See:

https://stackoverflow.com/a/63987798 and https://stackoverflow.com/a/67207300

Beware of not including the http/https as per the second answer above.

There is also a helpful Medium walkthough with a tonne more steps for before and after:

https://medium.com/@shivamgrg38/setting-up-http-to-https-and-non-www-to-www-redirects-for-external-http-s-load-balancers-on-b73be558eab5