Guide: Solo Mining With Remote Dcrd

I noticed on IRC that several people are having issues when trying to mine on one PC while dcrd is running on another PC, so I decided to write a quick guide to explain the pitfalls.

Some things you should know:

• The dcrd RPC port is bound to localhost by default. This means it is impossible to connect to from a remote machine.
• When you configure the dcrd RPC port to listen on anything else than localhost, it will not allow you to disable TLS
• By default, dcrd will generate a self-signed SSL certificate
• When connecting cgminer to anything with a self-signed certificate, this will fail

When you are running the wallet and your miner on the same machine, it is as simple as disabling TLS in dcrd (--notls), and use http://localhost:19109 as URL), but due to the above, this is not possible when you run them on different machines.

To allow cgminer to connect a service using a self-signed certificate, the decred developers have added an option to their cgminer fork:

What you need to do, is copy the self-signed certificate generated by dcrd to your mining machine. On a Linux machine you can find it in .dcrd/rpc.cert. If you transfer this file to your mining machine, and add the option --cert rpc.cert to cgminer, it should work.

If it doesn't, you should run cgminer with the --debug option. If you made a mistake, you will see this in cgminer output:

At the same time you will see this in dcrd output:

If you still get this, even after copying the certificate and passing it to cgminer, it probably can't find the certificate. Make sure you start cgminer from the same directory where you put the certificate. This is very important, as it seems cgminer doesn't complain if it can't find the certificate. Best thing would be to change the cgminer code so that it would complain if it can't find the path passed to the --cert option. I might submit a PR for this later, or someone can beat me to it

My apologies for this ugly-formatted post. I was in a hurry as I have to, and I usually don't post in forums, I am a die-hard IRC user.

EDIT: Linked to the Decred cgminer fork and cleaned up the formatting a bit..