Possible to open a port so that I can deploy API using R plumber?

jdoe

Hi there,
First off, love your service! Thank you for doing it. I have shared hosting on Opal3.

I'm midway through turning an R script into an API endpoint using R plumber. Following these instructions, I have successfully done things such as starting a PHP-Apache app in Opalstack, linking it to an Opalstack Domain and Site, installing R and Plumber, installing pm2 process manager, and startup/start of pm2. For example, I verified that my R file is actively running as a pm2 process and it is decorated with the necessary Plumber annotations.

But I'm running into a roadblock at the point that says "Wrap Your Plumber File." This step consists of running a command which activates a Plumber API running on host 0.0.0.0 (any IP4 connection) and port 4000 (i can choose anything).

Functionally I know how to execute this step, and I think I did it. However, at this point I believe I am supposed to be able to test by viewing the output of my API endpoint on a URL like http://my-app.my-account.opalstacked.com:4000/my-endpoint

However, I'm getting "This site can't be reached - ERR_CONNECTION_TIMED_OUT" when I try to view my endpoint URL.

My question is: Do I need to open this port (e.g. 4000) on Opalstack in order to allow external connections to that port? [FYI i can choose any port]

sean

jdoe You shouldn't need to have an open port for what you're trying to do. Instead you can do the following:

Go to https://my.opalstack.com/apps/ and create a new "Nginx Proxy Port" app, then locate the new app in your app list to see its port assignment.
Go to https://my.opalstack.com/domains/ and create a new site to serve your new app.
Spin up your app listening on the port that you got in step 1.

Once that's done our front-end Nginx server will receive requests for your site and proxy them to your app's port. Since it goes through the front-end server, it's served via the standard port 80 (or 443 if you're using HTTPS) and thus doesn't need a port number in the URL, eg http://my-app.my-account.opalstacked.com/my-endpoint.

If you do really need to access the port directly then we can open a port in the firewall for you, but it must be a port assigned to you via an app in your Opalstack dashboard via a proxy port app. Send an email to our support team to request that the port be opened in the firewall. Once that's done, spin up your project listening on the assigned port and you'll then be able to access http://my-app.my-account.opalstacked.com:XXXXX/my-endpoint.

jdoe

Thanks for this awesome answer. Totally makes sense. I'll give it a try!

sean

jdoe You're very welcome!

jdoe

It worked like a charm!