Node.js routing with Apache proxy - node.js

Question

I'm running Apache on a Linux server and find that my node.js apps routing doesn't work correctly when using URLS that go through Apache.
I followed instructions on other posts for turning on the proxy modules within apache and then set up this definition:
ProxyPass /testauth http://localhost:3000/
(I also had a line in there to define a similar reverse proxy that did nothing)
My node app runs on port 3000 with routing set up like in app.js
app.use('/', routes);
app.use('/tests', tests);
app.use('/questions', questions);
If I access URLs on my server like this:
http://rose.cs.umass.edu:3000/
http://rose.cs.umass.edu:3000/questions/179
I get correct results (note the styling with some simple CSS)
If I try to access thru apache like this:
http://rose.cs.umass.edu/testauth/questions/179
I get a 404 error but see from the backtrace that it is inside my js code.
For some reason the URL http://rose.cs.umass.edu/testauth partially works (but CSS doesn't get applied (because the index.ejs file includes the css like this:
<link rel='stylesheet' href='/stylesheets/style.css' />
The location of CSS files and the coding of relative paths follows all the node.js examples I have looked at and works fine in my development environment. But when running the app by going thru Apache, things are not working right.
Is there a fix to the apache config? Do I have to make an adjustment to how code paths in the my javascript and ejs files?

Answer 1

One clue I had to what was wrong is that node was printing the paths each time a request came in and they looked like
GET //questions/ 404 4.278 ms - 916
So I changed apache to have:
ProxyPass /testauth http://localhost:3000 (removed trailing slash)
Now the paths coming into my app were correctly formed.
The next order of business is to rework all the relative URLs in my EJS templates, client-side javascript, and even redirects in the server side.
Because I had to put "testauth" in the path so that Apache can forward to node, all the URLs coming into the app are of the form rose.cs.umass.edu/testauth/rest-of-url . This means relative URLs inside my app code that looked like
<a href="/questions" ....>
were now incorrect because they created absolute URLs that omitted the testauth in the path. Some of these relative URLs now are pretty strange (using things like ../ or even ../.. to get to things) . I wish there was a variable similar to ${pageContext.request.contextPath} that I use in JSP to build URLs.

Answer 2

I decided to mimic the JSP ${pageContext} idea
I added to file called config.js that has various settings that are particular to where the app is running (stuff like db credentials, etc). I added
// uncomment the line that applies
config.pageContext = "" // dev environment
// config.pageContext = "testauth" // production environment
My routing scripts all do something like:
res.render('questions', {pageContext: util.pageContext(req), questions: questionArray});
And the EJS templates all have stuff like this in the URLS:
<script src="<%= pageContext %>/static/js/bootstrap.min.js"></script>
A second alternative that I used for awhile until I went with the above:
Pass an argument to your node app when you start it. You then set a global variable similar to above and use it similarly. If you use a process manager (I use pm2) to run your node app on your server you might have to do something like:
pm2 start testauth -- -c /testauth // start testauth.bin using /testauth for the page context