ipfs service: Fix dataDir being ignored

[infinisil]

Motivation for this change

IPFS uses the environment variable IPFS_PATH to determine where to look for it's data, which wasn't set previously therefore ignoring the dataDir attribute.

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

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[mention-bot]

@infinisil, thanks for your PR! By analyzing the history of the files in this pull request, we identified @mguentner to be a potential reviewer.

[mguentner]

Ref: #21992

[Mic92]

What is your opinion on that? @mguentner

[infinisil]

There should also be added some note that TCP port 4001 optimally should be opened.

[mguentner]

That looks good to me, I am still not sure what to do with #21992. IMHO the IPFS_PATH should only be visible in the context of the daemon.

[infinisil]

I tested this now and it works with as is with the folder permissions, I'm not sure why though. I tested pinning and adding.

I'm not sure how PR's are handled exactly, #21992 has the same intention as this one, but doesn't actually work. With this PR IPFS_PATH is indeed only visible to the daemon and the systemd services.

[infinisil]

I just noticed something that was wrong all along: In the ipfs-start service, the script checks for ${cfg.dataDir}/.ipfs to already exists. But that folder never even gets generated by ipfs init. The confusion probably came from the default value ~/.ipfs.

Instead we should check for ${cfg.dataDir}/config, as the main implementation does. I'm going to open a new PR for that when I get the time.