Exposing localhost to the internet via tunneling (using ngrok): HTTP error 400: bad request; invalid hostname

From previous versions of the question, there is this: Browse website with ip address rather than localhost, which outlines pretty much what I've done so far...I've got the local IP working. Then I found ngrok, and apparently I don't need to connect via the IP.

What I am trying to do is expose my website running on localhost to the internet. I found a tool that will do this: ngrok.

Running the website in visual studio, the website starts up on localhost/port#. I run the command "ngrok http port#" in the command line. Everything seems to start up fine. I generate a couple of URLs, and the ngrok inspection url (localhost:4040) works.

The only problem is that when I go to the generated URLs, I get an HTTP error 400: bad request invalid hostname. This is a different error than when I run "ngrok http wrongport#", which is a host not found error...so I think something good is happening. I just can't tell what...

Is there a step I am missing in exposing my site to the internet via the tunneling service? If there is, I can't find it in the ngrok documentation.

Solution 1:

Troubleshot this issue with ngrok. In the words of inconshrevable, some applications get angry when they see a different host header than expected.

Running the following command should fix the problem:

ngrok http [port] -host-header="localhost:[port]"

Solution 2:

Following command will fix the issue

ngrok http -host-header=localhost 8080