flake.nix: run tests against pinned nixpkgs

and migrate to the new runTest, which evaluates much faster.

tests/clamav.nix

@@ -14,12 +14,17 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ pkgs ? import <nixpkgs> {}, blobs}:
+{
+  lib,
+  blobs,
+  ...
+}:
 
-pkgs.nixosTest {
+{
   name = "clamav";
+
   nodes = {
-    server = { config, pkgs, lib, ... }:
+    server = { pkgs, ... }:
         {
             imports = [
                 ../default.nix
@@ -28,6 +33,8 @@ pkgs.nixosTest {
 
             virtualisation.memorySize = 1500;
 
+            environment.systemPackages = with pkgs; [ netcat ];
+
             services.rsyslogd = {
               enable = true;
               defaultConfig = ''
@@ -83,7 +90,7 @@ pkgs.nixosTest {
               "root/eicar.com.txt".text = "X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*";
             };
         };
-      client = { nodes, config, pkgs, ... }: let
+      client = { nodes, pkgs, ... }: let
         serverIP = nodes.server.networking.primaryIPAddress;
         clientIP = nodes.client.networking.primaryIPAddress;
         grep-ip = pkgs.writeScriptBin "grep-ip" ''
@@ -180,8 +187,7 @@ pkgs.nixosTest {
       };
     };
 
-  testScript = { nodes, ... }:
-      ''
+  testScript = ''
       start_all()
 
       server.wait_for_unit("multi-user.target")
@@ -189,10 +195,10 @@ pkgs.nixosTest {
 
       # TODO put this blocking into the systemd units? I am not sure if rspamd already waits for the clamd socket.
       server.wait_until_succeeds(
-          "set +e; timeout 1 ${nodes.server.nixpkgs.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+          "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
       )
       server.wait_until_succeeds(
-          "set +e; timeout 1 ${nodes.server.nixpkgs.pkgs.netcat}/bin/nc -U /run/clamav/clamd.ctl < /dev/null; [ $? -eq 124 ]"
+          "set +e; timeout 1 nc -U /run/clamav/clamd.ctl < /dev/null; [ $? -eq 124 ]"
       )
 
       client.execute("cp -p /etc/root/.* ~/")