Automatically set distributed build's supportedFeatures based on that host's actual config.

Previously, we had two copies of the supported features for each host.

nix/configuration/flake.nix

@@ -69,6 +69,8 @@
 
             this_nixos_config = self.nixosConfigurations."${hostname}";
 
+            all_nixos_configs = self.nixosConfigurations;
+
             pkgs-unoptimized = import nixpkgs-unoptimized {
               inherit (nodeConfig) system;
               hostPlatform.gcc.arch = "default";

nix/configuration/hosts/i_only_boot_zfs/distributed_build.nix

@@ -3,12 +3,6 @@
 
   config = {
     me.distributed_build.enable = true;
-    me.distributed_build.machines.hydra = {
-      enable = true;
-      additional_config = {
-        speedFactor = 2;
-      };
-    };
     me.distributed_build.machines.quark = {
       enable = true;
       additional_config = {

nix/configuration/hosts/odo/distributed_build.nix

@@ -3,12 +3,6 @@
 
   config = {
     me.distributed_build.enable = true;
-    me.distributed_build.machines.hydra = {
-      enable = true;
-      additional_config = {
-        speedFactor = 2;
-      };
-    };
     me.distributed_build.machines.quark = {
       enable = true;
       additional_config = {

nix/configuration/hosts/odowork/distributed_build.nix

@@ -3,12 +3,6 @@
 
   config = {
     me.distributed_build.enable = true;
-    me.distributed_build.machines.hydra = {
-      enable = true;
-      additional_config = {
-        speedFactor = 2;
-      };
-    };
     me.distributed_build.machines.quark = {
       enable = true;
       additional_config = {

nix/configuration/hosts/quark/distributed_build.nix

@@ -3,11 +3,5 @@
 
   config = {
     me.distributed_build.enable = true;
-    me.distributed_build.machines.hydra = {
-      enable = true;
-      additional_config = {
-        speedFactor = 2;
-      };
-    };
   };
 }

nix/configuration/hosts/recovery/distributed_build.nix

@@ -3,12 +3,6 @@
 
   config = {
     me.distributed_build.enable = true;
-    me.distributed_build.machines.hydra = {
-      enable = true;
-      additional_config = {
-        speedFactor = 2;
-      };
-    };
     me.distributed_build.machines.quark = {
       enable = true;
       additional_config = {

nix/configuration/roles/distributed_build/default.nix

@@ -1,6 +1,7 @@
 {
   config,
   lib,
+  all_nixos_configs,
   ...
 }:
 
@@ -24,6 +25,18 @@ let
       description = "Additional config values for the buildMachines entry. For example, speedFactor.";
     };
   };
+
+  static_host_configs = {
+    quark = {
+      # From: base64 -w0 /persist/ssh/ssh_host_ed25519_key.pub
+      publicHostKey = "c3NoLWVkMjU1MTkgQUFBQUMzTnphQzFsWkRJMU5URTVBQUFBSUx0alplYlVYTkRkU3Y1enVGbjM3eFNMZUN3S2hPKzFMdWovM2FYNFJRTEEgcm9vdEBxdWFyawo=";
+      systems = [
+        "i686-linux"
+        "x86_64-linux"
+        # "aarch64-linux"
+      ];
+    };
+  };
 in
 {
   imports = [ ];
@@ -36,8 +49,7 @@ in
       description = "Whether we want to use multiple machines to perform a nixos-rebuild.";
     };
 
-    distributed_build.machines.hydra = make_machine_config "hydra";
+    distributed_build.machines = lib.mapAttrs (name: value: make_machine_config name) all_nixos_configs;
-    distributed_build.machines.quark = make_machine_config "quark";
   };
 
   config = lib.mkIf config.me.distributed_build.enable (
@@ -45,68 +57,26 @@ in
       {
         nix.distributedBuilds = true;
       }
-      (lib.mkIf config.me.distributed_build.machines.hydra.enable {
-        nix.buildMachines = [
-          (
       {
-              hostName = "hydra";
+        nix.buildMachines = (
-              sshUser = "nixworker";
+          map (
-              # sshKey = "";
+            hostname:
-              # publicHostKey = "";
+            (lib.mkIf config.me.distributed_build.machines."${hostname}".enable (
-              systems = [
+              lib.mkMerge [
-                "i686-linux"
-                "x86_64-linux"
-                # "aarch64-linux"
-              ];
-              maxJobs = 1;
-              supportedFeatures = [
-                "nixos-test"
-                "benchmark"
-                "big-parallel"
-                # "kvm"
-                "gccarch-x86-64-v3"
-                "gccarch-x86-64-v4"
-                "gccarch-skylake"
-                "gccarch-kabylake"
-                "gccarch-znver4"
-              ];
-            }
-            // config.me.distributed_build.machines.hydra.additional_config
-          )
-        ];
-      })
-      (lib.mkIf config.me.distributed_build.machines.quark.enable {
-        nix.buildMachines = [
-          (
                 {
-              hostName = "quark";
+                  hostName = hostname;
                   sshUser = "nixworker";
                   sshKey = "/persist/manual/ssh/root/keys/id_ed25519";
-              # From: base64 -w0 /persist/ssh/ssh_host_ed25519_key.pub
-              publicHostKey = "c3NoLWVkMjU1MTkgQUFBQUMzTnphQzFsWkRJMU5URTVBQUFBSUx0alplYlVYTkRkU3Y1enVGbjM3eFNMZUN3S2hPKzFMdWovM2FYNFJRTEEgcm9vdEBxdWFyawo=";
-              systems = [
-                "i686-linux"
-                "x86_64-linux"
-                # "aarch64-linux"
-              ];
                   maxJobs = 1;
-              supportedFeatures = [
+                  supportedFeatures = all_nixos_configs."${hostname}".config.me.optimizations.system_features;
-                "nixos-test"
+                }
-                "benchmark"
+                static_host_configs."${hostname}"
-                "big-parallel"
+                config.me.distributed_build.machines."${hostname}".additional_config
-                "kvm"
+              ]
-                "gccarch-x86-64-v3"
+            ))
-                "gccarch-x86-64-v4"
+          ) (builtins.attrNames all_nixos_configs)
-                "gccarch-skylake"
+        );
-                "gccarch-kabylake"
-                "gccarch-znver4"
-                "gccarch-znver5"
-              ];
       }
-            // config.me.distributed_build.machines.quark.additional_config
-          )
-        ];
-      })
     ]
   );
 }