nixos/vector: add graceful shutdown limit option

[nionata]

Add an option to the vector module to set the graceful shutdown limit added in vectordotdev/vector#17479. The option default mirrors the default from the vector cli. Alternatively, the option could be null as to be a no-op if it is not specified.

Eval and ExecStart output testing:

nix eval .#nixosTests.vector.api.nodes.machineapi.systemd.services.vector.serviceConfig.ExecStart
"/nix/store/870ikdmdf59v51shbrcqb7mpj34ddk4w-vector-0.47.0/bin/vector --config /nix/store/rpvw5mll6miahra8p96l456a6hj0sqhy-validate-vector-conf --graceful-shutdown-limit-secs 60

/nix/store/870ikdmdf59v51shbrcqb7mpj34ddk4w-vector-0.47.0/bin/vector --config /nix/store/rpvw5mll6miahra8p96l456a6hj0sqhy-validate-vector-conf --graceful-shutdown-limit-secs 60
...
^C2025-06-05T18:56:11.497323Z  INFO vector::signal: Signal received. signal="SIGINT"
2025-06-05T18:56:11.497521Z  INFO vector: Vector has stopped.
2025-06-05T18:56:11.499044Z  INFO vector::topology::running: Shutting down... Waiting on running components. remaining_components="demo_logs, file" time_remaining="59 seconds left"

/nix/store/870ikdmdf59v51shbrcqb7mpj34ddk4w-vector-0.47.0/bin/vector --config /nix/store/rpvw5mll6miahra8p96l456a6hj0sqhy-validate-vector-conf --graceful-shutdown-limit-secs 1
...
^C2025-06-05T18:56:20.408502Z  INFO vector::signal: Signal received. signal="SIGINT"
2025-06-05T18:56:20.408671Z  INFO vector: Vector has stopped.
2025-06-05T18:56:20.410253Z  INFO vector::topology::running: Shutting down... Waiting on running components. remaining_components="demo_logs, file" time_remaining="0 seconds left"

nixosTests:

nix-build -A nixosTests.vector

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• Nixpkgs 25.11 Release Notes (or backporting 24.11 and 25.05 Nixpkgs Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
• NixOS 25.11 Release Notes (or backporting 24.11 and 25.05 NixOS Release notes)
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

---

Add a 👍 reaction to pull requests you find important.

[dotlambda]

Please read https://github.com/NixOS/nixpkgs/blob/master/nixos/README.md#commit-conventions.

[dotlambda]

Please squash.

[nionata]

Please read https://github.com/NixOS/nixpkgs/blob/master/nixos/README.md#commit-conventions.

Thanks. I updated the PR title to comply with that format. Is that sufficient? Or is it desirable that I force push?

[dotlambda]

Please read https://github.com/NixOS/nixpkgs/blob/master/nixos/README.md#commit-conventions.

Thanks. I updated the PR title to comply with that format. Is that sufficient? Or is it desirable that I force push?

The latter.