nixos: adjust to 20.09 changes

Most notably the php5 expression needed to be reworked.

nix/os/containers/webserver.nix

@@ -2,7 +2,7 @@
 , localAddress
 , httpsPort ? 443
 }: {
-  config = { config, pkgs, ... }: {
+  config = { config, pkgs, lib, ... }: {
     imports = [
       ../profiles/containers/configuration.nix
     ];
@@ -30,23 +30,16 @@
       locations."~ ^(.+\.php)(.*)$".extraConfig = ''
         fastcgi_split_path_info  ^(.+\.php)(.*)$;
 
-        fastcgi_pass 127.0.0.1:9000;
+        fastcgi_pass unix:${config.services.phpfpm.pools.mypool.socket};
         fastcgi_index index.php;
       '';
     };
 
-    nixpkgs.config.php = {
-      imap = false;
-      openssl = false;
-      curl = false;
-      ldap = false;
-    };
-
     services.phpfpm.pools.mypool = {
-      phpPackage = pkgs.php56;
-      listen = "127.0.0.1:9000";
       user = "nobody";
+      phpPackage = pkgs.php5;
       settings = {
+        "listen.owner" = config.services.nginx.user;
         "pm" = "dynamic";
         "pm.max_children" = 5;
         "pm.start_servers" = 2;
@@ -58,6 +51,13 @@
       };
     };
 
+    # the custom php5 we're using here has no fpm-systemd, so the default `Type = "notify"` won't work
+    systemd.services."phpfpm-mypool" = {
+      serviceConfig = {
+        Type = lib.mkForce "simple";
+      };
+    };
+
     services.mysql = {
       enable = true;
       package = pkgs.mariadb;