Move the ceph client config to an external module

m/module/ceph.nix

@@ -0,0 +1,25 @@
+{ config, pkgs, ... }:
+
+# Mounts the /ceph filesystem at boot
+{
+  environment.systemPackages = with pkgs; [
+    ceph
+    ceph-client
+    fio # For benchmarks
+  ];
+
+  # We need the ceph module loaded as the mount.ceph binary fails to run the
+  # modprobe command.
+  boot.kernelModules = [ "ceph" ];
+
+  age.secrets.cephUser.file = ../../secrets/ceph-user.age;
+
+  fileSystems."/ceph" = {
+    fsType = "ceph";
+    device = "user@9c8d06e0-485f-4aaf-b16b-06d6daf1232b.cephfs=/";
+    options = [
+      "mon_addr=10.0.40.40"
+      "secretfile=${config.age.secrets.cephUser.path}"
+    ];
+  };
+}