Heroku Static IP for SFTP

问题:

I have an application deployed to Heroku. I'm using a service that requires me to access their SFTP server using a static ip address. I know Heroku dynos are unreliable in this regard. I have successfully achieved this using the Proximo addon, however, its too expensive for the amount of traffic that I'll be sending (around 500 MB/month). Is there an alternate to this? I'm inclined towards using an EC2 instance but not quite sure what's required to create a proxy or whatever.

回答1:

I'd go with an EC2 micro instance; pushing bits around doesn't really consume much CPU, so it's unlikely to get throttled. I would then give that instance an elastic IP address and communicate that address to the other service. (Whatever I choose to do later, I can always spin up another instance and associate it to that IP.) I would then deploy a SOCKS proxy (Dante?); SOCKS has pretty widespread application support, and it can handle SFTP just fine.

From here, there are a couple details specific to Heroku -- for one, you'll want to configure your proxy server's EC2 security group such that Heroku can access it (see Dynos and the Dyno Manifold). You'll also want to enable authentication on the SOCKS server, since granting Heroku access to your proxy grants everyone in Heroku access to your proxy. Then, heroku config:set SOME_SERVICE_SOCKS_PROXY=socks://user:[e-mail], and have your application look for that environment variable and do the right thing.

You'll likely be paying $0.01/GB for intra-region data transfer between your proxy and Heroku, since statistically, your application will be in a different availability zone most of the time. Heroku dynos last about 24 hours in production, so while the exact location will dance around unpredictably, it'll probably land in the $0.008/GB range in aggregate. You'll also be paying for the micro instance itself (though reserved instances make them stupid cheap) as well as the usual AWS Internet data transfer rates.