Previously we had three services for different config flavors. This is
confusing because only one instance of IPFS can run on a host / port
combination at once. So move all into ipfs.service, which contains the
configuration specified in services.ipfs.

Also remove the env wrapper and just use systemd env configuration.

This makes it possible to only start IPFS when needed. So a user’s
IPFS daemon only starts when they actually use it.

A few important warnings though:

  - This probably shouldn’t be mixed with services.ipfs.autoMount
    since you want /ipfs and /ipns aren’t activated like this
  - ipfs.socket assumes that you are using ports 5001 and 8080 for the
    API and gateway respectively. We could do some parsing to figure
    out what is in apiAddress and gatewayAddress, but that’s kind of
    difficult given the nonstandard address format.
  - Apparently? this doesn’t work with the --api commands used in the tests.

Of course you can always start automatically with startWhenNeeded =
false, or just running ‘systemctl start ipfs.service’.

Tested with the following test (modified from tests/ipfs.nix):

  import ./make-test-python.nix ({ pkgs, ...} : {
    name = "ipfs";

    nodes.machine = { ... }: {
      services.ipfs = {
        enable = true;
        startWhenNeeded = true;
      };
    };

    testScript = ''
      start_all()

      machine.wait_until_succeeds("ipfs id")
      ipfs_hash = machine.succeed("echo fnord | ipfs add | awk '{ print $2 }'")

      machine.succeed(f"ipfs cat /ipfs/{ipfs_hash.strip()} | grep fnord")
    '';
  })

Fixes #90145

Update nixos/modules/services/network-filesystems/ipfs.nix

Co-authored-by: Florian Klink <flokli@flokli.de>

Add socket-based IPFS support