docs: add linkcheck

dev/docs.nix

@@ -23,5 +23,19 @@
         cd $files
         mkdocs build --strict --site-dir $out
       '';
+    docs-linkcheck = pkgs.testers.lycheeLinkCheck rec {
+      extraConfig = {
+        exclude = [
+          "https://fonts.gstatic.com"
+          "https://monitoring.nix-community.org/alertmanager" # 401 behind auth
+        ];
+        include_mail = true;
+        include_verbatim = true;
+      };
+      remap = {
+        "https://nix-community.org" = site;
+      };
+      site = config.packages.docs;
+    };
   };
 }

flake.nix

@@ -83,7 +83,7 @@
               darwinConfigurations // devShells // { inherit (self') formatter; } // nixosConfigurations
               // pkgs.lib.optionalAttrs (system == "x86_64-linux")
                 {
-                  inherit (self'.packages) docs;
+                  inherit (self'.packages) docs docs-linkcheck;
                   nixpkgs-update-supervisor-test = pkgs.callPackage ./hosts/build02/supervisor_test.nix { };
                   nixosTests-buildbot = pkgs.nixosTests.buildbot;
                   nixosTests-buildbot-nix-master = inputs'.buildbot-nix.checks.master;

tasks.py

@@ -108,6 +108,14 @@ def mkdocs(c: Any) -> None:
     c.run("nix develop .#mkdocs -c mkdocs serve")
 
 
+@task
+def docs_linkcheck(c: Any) -> None:
+    """
+    Run docs online linkchecker
+    """
+    c.run("nix run .#docs-linkcheck.online")
+
+
 def get_hosts(hosts: str) -> List[DeployHost]:
     if hosts == "":
         res = subprocess.run(