How do you run two nodes on a single machine?

[mikeal]

I’m on the latest js-ipfs on Node.js v10 on Linux.

I’m writing a command line utility and each invocation of the utility creates an IPFS node. The first one runs fine, but when I try to do a second invocation while the first is still running the new invocation just exits. No error, no exception, nothing, just an exit.

This is because the ready event never fires and because the node never binds to a port the process runs out of things to do and just exits. I suspect this is due to listen port conflicts, so I attempted to change the ports, that I’m sort of lost in the layers where the config I’m trying to pass in actually makes it to libp2p, I’m not sure what exactly I’m doing wrong because I never get an error — the process just exits.

Anyway, is there a guide or example anywhere of all the little things I need to adjust to run two nodes on the same machine?

[alanshaw]

Firstly, you'll want to use the IPFS_PATH env variable or pass the repo option to the constructor to get a different repo for each instance.

e.g.

CLI:

IPFS_PATH=~/.jsipfs2 jsipfs init

Programmatically:

new IPFS({ repo: os.homedir() + '/.jsipfs2' })

Secondly, you'll need them to bind to different ports because otherwise bad things happen.

With the CLI, after you've run ipfs init you can either edit the config file at ~/.jsipfs/config (replacing ~/.jsipfs with the repo path you specified above) or use the config command to update the config e.g. ipfs config Addresses.API /ip4/0.0.0.0/tcp/4012. Then start the node with ipfs daemon. Or if you're doing this programmatically you can simply pass the different ports to the config constructor option.

e.g.

CLI:

# edit the address ports
vi ~/.jsipfs2/config

# ...and then start the daemon
IPFS_PATH=~/.jsipfs2 jsipfs daemon

or

IPFS_PATH=~/.jsipfs2 jsipfs config Addresses.API /ip4/127.0.0.1/tcp/5012
# etc...

# ...and then start the daemon
IPFS_PATH=~/.jsipfs2 jsipfs daemon

Programmatically:

new IPFS({
  config: {
    Addresses: {
      Swarm: [
        '/ip4/0.0.0.0/tcp/4012',
        '/ip4/127.0.0.1/tcp/4013/ws'
      ],
      API: '/ip4/127.0.0.1/tcp/5012',
      Gateway: '/ip4/127.0.0.1/tcp/9191'
    }
  }
})

Thirdly, yes I've noticed error's being swallowed and I intend to fix it asap. Issue here libp2p/js-libp2p#311 and I'll double check if this is a problem in JS IPFS or not now.

Hope that helps!

[alanshaw]

Where do you think would be a good place to put this info?

[mikeal]

Where do you think would be a good place to put this info?

The code one we should use in a new example in the examples directory. The CLI stuff I’m less sure about, maybe we need some different doc files with notes on common use cases we can just link to in the main README?