flake: enable pre-commit hooks

.gitignore

@@ -1,3 +1,4 @@
 result*
 /.direnv
 target
+/.pre-commit-config.yaml

flake.lock

@@ -59,6 +59,22 @@
         "type": "github"
       }
     },
+    "flake-compat_3": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1668681692,
+        "narHash": "sha256-Ht91NGdewz8IQLtWZ9LCeNXMSXHUss+9COoqu6JLmXU=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "009399224d5e398d03b22badca40a37ac85412a1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib"
@@ -92,6 +108,27 @@
         "type": "github"
       }
     },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "pre-commit-hooks-nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1660459072,
+        "narHash": "sha256-8DFJjXG8zqoONA1vXtgeKXy68KdJL5UaXR8NtVMUbx8=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "a20de23b925fd8264fd7fad6454652e142fd7f73",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1673039641,
@@ -126,6 +163,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1671271954,
+        "narHash": "sha256-cSvu+bnvN08sOlTBWbBrKaBHQZq8mvk8bgpt0ZJ2Snc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d513b448cc2a6da2c8803e3c197c9fc7e67b19e3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-22.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixpkgs-test": {
       "locked": {
         "lastModified": 1671812130,
@@ -142,6 +195,32 @@
         "type": "github"
       }
     },
+    "pre-commit-hooks-nix": {
+      "inputs": {
+        "flake-compat": "flake-compat_3",
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": "nixpkgs-stable"
+      },
+      "locked": {
+        "lastModified": 1672912243,
+        "narHash": "sha256-QnQeKUjco2kO9J4rBqIBPp5XcOMblIMnmyhpjeaJBYc=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "a4548c09eac4afb592ab2614f4a150120b29584c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "crane": "crane",
@@ -150,6 +229,7 @@
         "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs",
         "nixpkgs-test": "nixpkgs-test",
+        "pre-commit-hooks-nix": "pre-commit-hooks-nix",
         "rust-overlay": "rust-overlay"
       }
     },

flake.nix

@@ -7,6 +7,12 @@
 
     flake-parts.url = "github:hercules-ci/flake-parts";
 
+    pre-commit-hooks-nix = {
+      url = "github:cachix/pre-commit-hooks.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-utils.follows = "flake-utils";
+    };
+
     # We only have this input to pass it to other dependencies and
     # avoid having mulitple versions in our dependencies.
     flake-utils.url = "github:numtide/flake-utils";
@@ -35,6 +41,9 @@
       imports = [
         # Derive the output overlay automatically from all packages that we define.
         inputs.flake-parts.flakeModules.easyOverlay
+
+        # Formatting and quality checks.
+        inputs.pre-commit-hooks-nix.flakeModule
       ];
 
       flake.nixosModules.lanzaboote = moduleWithSystem (
@@ -146,7 +155,15 @@
           lanzabooteModule = self.nixosModules.lanzaboote;
         });
 
+        pre-commit = {
+          check.enable = true;
+        };
+
         devShells.default = pkgs.mkShell {
+          shellHook = ''
+            ${config.pre-commit.installationScript}
+          '';
+
           packages = let
             uefi-run = pkgs.callPackage ./nix/packages/uefi-run.nix {
               inherit craneLib;