zfs: enable keylocation=http://

When ZFS is built with cURL, it allows retrieving encryption keys from
URLs automatically.

nixos/tests/zfs.nix

@@ -80,6 +80,11 @@ let
             fsType = "zfs";
             options = [ "noauto" ];
           };
+          virtualisation.fileSystems."/manual/httpkey" = {
+            device = "manual/httpkey";
+            fsType = "zfs";
+            options = [ "noauto" ];
+          };
         };
 
         specialisation.forcepool.configuration = {
@@ -92,6 +97,19 @@ let
             options = [ "noauto" ];
           };
         };
+
+        services.nginx = {
+          enable = true;
+          virtualHosts = {
+            localhost = {
+              locations = {
+                "/zfskey" = {
+                  return = ''200 "httpkeyabc"'';
+                };
+              };
+            };
+          };
+        };
       };
 
       testScript = ''
@@ -130,6 +148,8 @@ let
                 "zpool create -O mountpoint=legacy manual /dev/vdd1",
                 "echo otherpass | zfs create "
                 + "-o encryption=aes-256-gcm -o keyformat=passphrase manual/encrypted",
+                "zfs create -o encryption=aes-256-gcm -o keyformat=passphrase "
+                + "-o keylocation=http://localhost/zfskey manual/httpkey",
                 "bootctl set-default nixos-generation-1-specialisation-encryption.conf",
                 "sync",
                 "zpool export automatic",
@@ -141,10 +161,12 @@ let
             machine.send_console("password\n")
             machine.wait_for_unit("multi-user.target")
             machine.succeed(
-                "zfs get keystatus manual/encrypted | grep unavailable",
+                "zfs get -Ho value keystatus manual/encrypted | grep -Fx unavailable",
                 "echo otherpass | zfs load-key manual/encrypted",
                 "systemctl start manual-encrypted.mount",
-                "umount /automatic /manual/encrypted /manual",
+                "zfs load-key manual/httpkey",
+                "systemctl start manual-httpkey.mount",
+                "umount /automatic /manual/encrypted /manual/httpkey /manual",
                 "zpool destroy automatic",
                 "zpool destroy manual",
             )

pkgs/os-specific/linux/zfs/default.nix

@@ -10,6 +10,7 @@
 , gawk, gnugrep, gnused, systemd
 , smartmontools, enableMail ? false
 , sysstat, pkg-config
+, curl
 
 # Kernel dependencies
 , kernel ? null
@@ -76,6 +77,8 @@ let
           nfs-utils.override (old: { enablePython = old.enablePython or true && enablePython; })
         }/bin/exportfs"
         substituteInPlace ./lib/libshare/smb.h        --replace "/usr/bin/net"            "${samba}/bin/net"
+        # Disable dynamic loading of libcurl
+        substituteInPlace ./config/user-libfetch.m4   --replace "curl-config --built-shared" "true"
         substituteInPlace ./config/user-systemd.m4    --replace "/usr/lib/modules-load.d" "$out/etc/modules-load.d"
         substituteInPlace ./config/zfs-build.m4       --replace "\$sysconfdir/init.d"     "$out/etc/init.d" \
                                                       --replace "/etc/default"            "$out/etc/default"
@@ -111,6 +114,7 @@ let
         ++ optional buildUser pkg-config;
       buildInputs = optionals buildUser [ zlib libuuid attr libtirpc ]
         ++ optional buildUser openssl
+        ++ optional buildUser curl
         ++ optional (buildUser && enablePython) python3;
 
       # for zdb to get the rpath to libgcc_s, needed for pthread_cancel to work