Introduce a dedicated networking.proxy option

Following the discussion NixOS#5021:
- obsolete the nix.proxy option
- add the networking.proxy option
- open a default no_proxy environment variable
- add a rsync option
- Manual tests ok.
- Automatic tests ok.

Amended by lethalman to simplify the option descriptions.

nixos/modules/config/networking.nix

@@ -39,6 +39,73 @@ in
       '';
     };
 
+    networking.proxy = {
+
+      default = lib.mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          This option specifies the default value for httpProxy, httpsProxy, ftpProxy and rsyncProxy.
+        '';
+        example = "http://127.0.0.1:3128";
+      };
+
+      httpProxy = lib.mkOption {
+        type = types.nullOr types.str;
+        default = cfg.proxy.default;
+        description = ''
+          This option specifies the http_proxy environment variable.
+        '';
+        example = "http://127.0.0.1:3128";
+      };
+
+      httpsProxy = lib.mkOption {
+        type = types.nullOr types.str;
+        default = cfg.proxy.default;
+        description = ''
+          This option specifies the https_proxy environment variable.
+        '';
+        example = "http://127.0.0.1:3128";
+      };
+
+      ftpProxy = lib.mkOption {
+        type = types.nullOr types.str;
+        default = cfg.proxy.default;
+        description = ''
+          This option specifies the ftp_proxy environment variable.
+        '';
+        example = "http://127.0.0.1:3128";
+      };
+
+      rsyncProxy = lib.mkOption {
+        type = types.nullOr types.str;
+        default = cfg.proxy.default;
+        description = ''
+          This option specifies the rsync_proxy environment variable.
+        '';
+        example = "http://127.0.0.1:3128";
+      };
+
+      noProxy = lib.mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          This option specifies the no_proxy environment variable.
+          If a default proxy is used and noProxy is null,
+          then noProxy will be set to 127.0.0.1,localhost.
+        '';
+        example = "127.0.0.1,localhost,.localdomain";
+      };
+
+      envVars = lib.mkOption {
+        type = types.attrs;
+        internal = true;
+        default = {};
+        description = ''
+          Environment variables used for the network proxy.
+        '';
+      };
+    };
   };
 
   config = {
@@ -93,6 +160,25 @@ in
         }
       ));
 
+      networking.proxy.envVars =
+        optionalAttrs (cfg.proxy.default != null) {
+          # other options already fallback to proxy.default
+          no_proxy = "127.0.0.1,localhost";
+        } // optionalAttrs (cfg.proxy.httpProxy != null) {
+          http_proxy  = cfg.proxy.httpProxy;
+        } // optionalAttrs (cfg.proxy.httpsProxy != null) {
+          https_proxy = cfg.proxy.httpsProxy;
+        } // optionalAttrs (cfg.proxy.rsyncProxy != null) {
+          rsync_proxy = cfg.proxy.rsyncProxy;
+        } // optionalAttrs (cfg.proxy.ftpProxy != null) {
+          ftp_proxy   = cfg.proxy.ftpProxy;
+        } // optionalAttrs (cfg.proxy.noProxy != null) {
+          no_proxy    = cfg.proxy.noProxy;
+        };
+
+    # Install the proxy environment variables
+    environment.sessionVariables = config.networking.proxy.envVars;
+
     # The ‘ip-up’ target is started when we have IP connectivity.  So
     # services that depend on IP connectivity (like ntpd) should be
     # pulled in by this target.
@@ -120,4 +206,4 @@ in
 
   };
 
-}
+  }

nixos/modules/rename.nix

@@ -110,6 +110,9 @@ in zipModules ([]
 # VirtualBox
 ++ obsolete [ "services" "virtualbox" "enable" ] [ "services" "virtualboxGuest" "enable" ]
 
+# proxy
+++ obsolete [ "nix" "proxy" ] [ "networking" "proxy" "default" ]
+
 # KDE
 ++ deprecated [ "kde" "extraPackages" ] [ "environment" "kdePackages" ]
 # ++ obsolete [ "environment" "kdePackages" ] [ "environment" "systemPackages" ] # !!! doesn't work!

nixos/modules/services/misc/nix-daemon.nix

@@ -193,17 +193,6 @@ in
         '';
       };
 
-      proxy = mkOption {
-        type = types.str;
-        default = "";
-        description = ''
-          This option specifies the proxy to use for fetchurl. The real effect
-          is just exporting http_proxy, https_proxy and ftp_proxy with that
-          value.
-        '';
-        example = "http://127.0.0.1:3128";
-      };
-
       # Environment variables for running Nix.
       envVars = mkOption {
         type = types.attrs;
@@ -317,13 +306,6 @@ in
         NIX_BUILD_HOOK = "${nix}/libexec/nix/build-remote.pl";
         NIX_REMOTE_SYSTEMS = "/etc/nix/machines";
         NIX_CURRENT_LOAD = "/run/nix/current-load";
-      }
-
-      # !!! These should not be defined here, but in some general proxy configuration module!
-      // optionalAttrs (cfg.proxy != "") {
-        http_proxy = cfg.proxy;
-        https_proxy = cfg.proxy;
-        ftp_proxy = cfg.proxy;
       };
 
     # Set up the environment variables for running Nix.

nixos/tests/networking-proxy.nix

@@ -0,0 +1,109 @@
+# Test whether `networking.proxy' work as expected.
+
+# TODO: use a real proxy node and put this test into networking.nix
+# TODO: test whether nix tools work as expected behind a proxy
+
+let default-config = {
+        imports = [ ./common/user-account.nix ];
+
+        services.xserver.enable = false;
+
+        virtualisation.memorySize = 128;
+      };
+in import ./make-test.nix {
+  name = "networking-proxy";
+
+  nodes = {
+    # no proxy
+    machine =
+      { config, pkgs, ... }:
+
+      default-config;
+
+    # proxy default
+    machine2 =
+      { config, pkgs, ... }:
+
+      default-config // {
+        networking.proxy.default = "http://user:pass@host:port";
+      };
+
+    # specific proxy options
+    machine3 =
+      { config, pkgs, ... }:
+
+      default-config //
+      {
+        networking.proxy = {
+          # useless because overriden by the next options
+          default = "http://user:pass@host:port";
+          # advanced proxy setup
+          httpProxy = "123-http://user:pass@http-host:port";
+          httpsProxy = "456-http://user:pass@https-host:port";
+          rsyncProxy = "789-http://user:pass@rsync-host:port";
+          ftpProxy = "101112-http://user:pass@ftp-host:port";
+          noProxy = "131415-127.0.0.1,localhost,.localdomain";
+        };
+      };
+
+    # mix default + proxy options
+    machine4 =
+      { config, pkgs, ... }:
+
+      default-config // {
+        networking.proxy = {
+          # open for all *_proxy env var
+          default = "000-http://user:pass@default-host:port";
+          # except for those 2
+          rsyncProxy = "123-http://user:pass@http-host:port";
+          noProxy = "131415-127.0.0.1,localhost,.localdomain";
+        };
+      };
+    };
+
+  testScript =
+    ''
+      startAll;
+
+      # no proxy at all
+      print $machine->execute("env | grep -i proxy");
+      print $machine->execute("su - alice -c 'env | grep -i proxy'");
+      $machine->mustFail("env | grep -i proxy");
+      $machine->mustFail("su - alice -c 'env | grep -i proxy'");
+
+      # Use a default proxy option
+      print $machine2->execute("env | grep -i proxy");
+      print $machine2->execute("su - alice -c 'env | grep -i proxy'");
+      $machine2->mustSucceed("env | grep -i proxy");
+      $machine2->mustSucceed("su - alice -c 'env | grep -i proxy'");
+
+      # explicitly set each proxy option
+      print $machine3->execute("env | grep -i proxy");
+      print $machine3->execute("su - alice -c 'env | grep -i proxy'");
+      $machine3->mustSucceed("env | grep -i http_proxy | grep 123");
+      $machine3->mustSucceed("env | grep -i https_proxy | grep 456");
+      $machine3->mustSucceed("env | grep -i rsync_proxy | grep 789");
+      $machine3->mustSucceed("env | grep -i ftp_proxy | grep 101112");
+      $machine3->mustSucceed("env | grep -i no_proxy | grep 131415");
+      $machine3->mustSucceed("su - alice -c 'env | grep -i http_proxy | grep 123'");
+      $machine3->mustSucceed("su - alice -c 'env | grep -i https_proxy | grep 456'");
+      $machine3->mustSucceed("su - alice -c 'env | grep -i rsync_proxy | grep 789'");
+      $machine3->mustSucceed("su - alice -c 'env | grep -i ftp_proxy | grep 101112'");
+      $machine3->mustSucceed("su - alice -c 'env | grep -i no_proxy | grep 131415'");
+
+      # set default proxy option + some other specifics
+      print $machine4->execute("env | grep -i proxy");
+      print $machine4->execute("su - alice -c 'env | grep -i proxy'");
+      $machine4->mustSucceed("env | grep -i http_proxy | grep 000");
+      $machine4->mustSucceed("env | grep -i https_proxy | grep 000");
+      $machine4->mustSucceed("env | grep -i rsync_proxy | grep 123");
+      $machine4->mustSucceed("env | grep -i ftp_proxy | grep 000");
+      $machine4->mustSucceed("env | grep -i no_proxy | grep 131415");
+      $machine4->mustSucceed("su - alice -c 'env | grep -i http_proxy | grep 000'");
+      $machine4->mustSucceed("su - alice -c 'env | grep -i https_proxy | grep 000'");
+      $machine4->mustSucceed("su - alice -c 'env | grep -i rsync_proxy | grep 123'");
+      $machine4->mustSucceed("su - alice -c 'env | grep -i ftp_proxy | grep 000'");
+      $machine4->mustSucceed("su - alice -c 'env | grep -i no_proxy | grep 131415'");
+    '';
+
+}