This seems a bit more challenging than just generally getting the url + path due to express being served from a secondary path.
I'm trying to dynamically create redirect/callback URL's for passport based OpenID integrations.
So far, I've successfully gotten as much using the req.host as directed in other stackoverflow threads:
callbackURL: "https://" + req.get("host") + "/auth/apple/redirect",
I do not need protocol as I'm only dealing with https all the time.
The issue is, my function is being served from:
https://europe-west2-projectname.cloudfunctions.net/MY_FUNCTION_NAME/
and therefore using just host, the url above will not be a valid redirect URL that Oauth can use.
I am doing this as I have 1 single app running off of 2 different functions depending if i'm in staging OR production.
To further add insult to injury -- firebase functions within the same app seem to share their environmental variables so I can't really count on those either.