refactor deployments

Closes #103

At last, a fully fledged data model for what Fediversity really is and does. This comes with a test that exercises a very simple but functionally complete arrangement with all ingredients fo the business logic: a dummy resource (login shell), a dummy application (`hello`, which needs a shell to live in), a dummy environment (a single NixOS VM that allows for one, the operator's, login shell), and a deployment of that environment given a dummy configuration (that enables `hello`).

The next step will be to lift this purely evaluation-level test into a VM test which verifies that the resulting VM indeed has `hello` deployed to the operator's user account.

Caveats:
- The exact naming has a bit of room for improvement, and may have diverged from the design document
- The test is not as pedantically type safe as it could be, since we simply use `types.raw` for resources such as NixOS users settings which *could* be more finely delineated

Co-authored-by: Kiara Grouwstra <kiara@procolix.eu>
Co-authored-by: kiara Grouwstra <kiara@procolix.eu>
Reviewed-on: Fediversity/Fediversity#481
Reviewed-by: kiara Grouwstra <kiara@procolix.eu>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-committed-by: Valentin Gagarin <valentin.gagarin@tweag.io>

.forgejo/workflows/ci.yaml

@@ -56,3 +56,29 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - run: nix build .#checks.x86_64-linux.deployment-panel -L
+
+  ## NOTE: NixOps4 does not provide a good “dry run” mode, so we instead check
+  ## proxies for resources, namely whether their `.#vmOptions.<machine>` and
+  ## `.#nixosConfigurations.<machine>` outputs evaluate and build correctly, and
+  ## whether we can dry run `infra/proxmox-*.sh` on them. This will not catch
+  ## everything, and in particular not issues in how NixOps4 wires up the
+  ## resources, but that is still something.
+  check-resources:
+    runs-on: native
+    steps:
+      - uses: actions/checkout@v4
+      - run: |
+          set -euC
+          echo ==================== [ VM Options ] ====================
+          machines=$(nix eval --impure --raw --expr 'with builtins; toString (attrNames (getFlake (toString ./.)).vmOptions)')
+          for machine in $machines; do
+            echo ~~~~~~~~~~~~~~~~~~~~~: $machine :~~~~~~~~~~~~~~~~~~~~~
+            nix build .#checks.x86_64-linux.vmOptions-$machine
+          done
+          echo
+          echo ==================== [ NixOS Configurations ] ====================
+          machines=$(nix eval --impure --raw --expr 'with builtins; toString (attrNames (getFlake (toString ./.)).nixosConfigurations)')
+          for machine in $machines; do
+            echo ~~~~~~~~~~~~~~~~~~~~~: $machine :~~~~~~~~~~~~~~~~~~~~~
+            nix build .#checks.x86_64-linux.nixosConfigurations-$machine
+          done

default.nix

@@ -11,7 +11,8 @@ let
     ;
   inherit (pkgs) lib;
   inherit (import sources.flake-inputs) import-flake;
-  inherit ((import-flake { src = ./.; }).inputs) nixops4;
+  inputs = (import-flake { src = ./.; }).inputs;
+  inherit (inputs) nixops4;
   panel = import ./panel { inherit sources system; };
   pre-commit-check =
     (import "${git-hooks}/nix" {
@@ -78,6 +79,7 @@ in
   # re-export inputs so they can be overridden granularly
   # (they can't be accessed from the outside any other way)
   inherit
+    inputs
     sources
     system
     pkgs

deployment/check/common/nixosTest.nix

@@ -48,7 +48,8 @@ in
     extraTestScript = mkOption { };
 
     sourceFileset = mkOption {
-      ## REVIEW: Upstream to nixpkgs?
+      ## FIXME: grab `lib.types.fileset` from NixOS, once upstreaming PR
+      ## https://github.com/NixOS/nixpkgs/pull/428293 lands.
       type = types.mkOptionType {
         name = "fileset";
         description = "fileset";

deployment/data-model-test.nix

@@ -1,7 +1,7 @@
 let
   inherit (import ../default.nix { }) pkgs inputs;
   inherit (pkgs) lib;
-  inherit (lib) mkOption;
+  inherit (lib) mkOption types;
   eval =
     module:
     (lib.evalModules {
@@ -13,17 +13,82 @@ let
         ./data-model.nix
       ];
     }).config;
+  inherit (inputs.nixops4.lib) mkDeployment;
 in
 {
   _class = "nix-unit";
 
   test-eval = {
+    /**
+      This tests a very simple arrangement that features all ingredients of the Fediversity business logic:
+      application, resource, environment, deployment; and wires it all up in one end-to-end exercise.
+      - The dummy resource is a login shell made available for some user.
+      - The dummy application is `hello` that requires a shell to be deployed.
+      - The dummy environment is a single NixOS VM that hosts one login shell, for the operator.
+      - The dummy configuration enables the `hello` application.
+      This will produce a NixOps4 deployment for a NixOS VM with a login shell for the operator and `hello` available.
+    */
     expr =
       let
         fediversity = eval (
           { config, ... }:
           {
             config = {
+              resources.login-shell = {
+                description = "The operator needs to be able to log into the shell";
+                request =
+                  { ... }:
+                  {
+                    _class = "fediversity-resource-request";
+                    options = {
+                      wheel = mkOption {
+                        description = "Whether the login user needs root permissions";
+                        type = types.bool;
+                        default = false;
+                      };
+                      packages = mkOption {
+                        description = "Packages that need to be available in the user environment";
+                        type = with types; attrsOf package;
+                      };
+                    };
+                  };
+                policy =
+                  { config, ... }:
+                  {
+                    _class = "fediversity-resource-policy";
+                    options = {
+                      username = mkOption {
+                        description = "Username for the operator";
+                        type = types.str; # TODO: use the proper constraints from NixOS
+                      };
+                      wheel = mkOption {
+                        description = "Whether to allow login with root permissions";
+                        type = types.bool;
+                        default = false;
+                      };
+                    };
+                    config = {
+                      resource-type = types.raw; # TODO: splice out the user type from NixOS
+                      apply =
+                        requests:
+                        let
+                          # Filter out requests that need wheel if policy doesn't allow it
+                          validRequests = lib.filterAttrs (
+                            _name: req: !req.login-shell.wheel || config.wheel
+                          ) requests.resources;
+                        in
+                        lib.optionalAttrs (validRequests != { }) {
+                          ${config.username} = {
+                            isNormalUser = true;
+                            packages =
+                              with lib;
+                              attrValues (concatMapAttrs (_name: request: request.login-shell.packages) validRequests);
+                            extraGroups = lib.optional config.wheel "wheel";
+                          };
+                        };
+                    };
+                  };
+              };
               applications.hello =
                 { ... }:
                 {
@@ -31,16 +96,47 @@ in
                   module =
                     { ... }:
                     {
-                      options = {
-                        enable = lib.mkEnableOption "Hello in the shell";
-                      };
+                      options.enable = lib.mkEnableOption "Hello in the shell";
                     };
-                  implementation =
-                    cfg:
-                    lib.optionalAttrs cfg.enable {
-                      dummy.login-shell.packages.hello = pkgs.hello;
+                  implementation = cfg: {
+                    input = cfg;
+                    output = lib.optionalAttrs cfg.enable {
+                      resources.hello.login-shell.packages.hello = pkgs.hello;
                     };
+                  };
                 };
+              environments.single-nixos-vm =
+                { config, ... }:
+                {
+                  resources.operator-environment.login-shell.username = "operator";
+                  implementation = requests: {
+                    input = requests;
+                    output =
+                      { providers, ... }:
+                      {
+                        providers = {
+                          inherit (inputs.nixops4.modules.nixops4Provider) local;
+                        };
+                        resources.the-machine = {
+                          type = providers.local.exec;
+                          imports = [
+                            inputs.nixops4-nixos.modules.nixops4Resource.nixos
+                          ];
+                          nixos.module =
+                            { ... }:
+                            {
+                              users.users = config.resources.shell.login-shell.apply (
+                                lib.filterAttrs (_name: value: value ? login-shell) requests
+                              );
+                            };
+                        };
+                      };
+                  };
+                };
+              deployments.example = {
+                environment = config.environments.single-nixos-vm;
+                configuration = config.example-configuration;
+              };
             };
             options = {
               example-configuration = mkOption {
@@ -54,17 +150,63 @@ in
             };
           }
         );
+        resources = fediversity.example-configuration.required-resources.hello;
+        hello-shell = resources.resources.hello.login-shell;
+        environment = fediversity.environments.single-nixos-vm.resources.operator-environment.login-shell;
+        result = mkDeployment {
+          modules = [
+            fediversity.deployments.example.deployment
+          ];
+        };
+
       in
       {
-        inherit (fediversity)
-          example-configuration
-          ;
+        number-of-resources = with lib; length (attrNames fediversity.resources);
+        # XXX: nix-unit unlike nix-build seems to hit infinite recursions on
+        # evaluation of package paths, so we avoid evaluating
+        # fediversity.example-configuration.required-resources.hello.resources.hello.login-shell.packages.hello
+        example-configuration = {
+          inherit (fediversity.example-configuration) enable applications;
+        };
+        hello-package-exists = hello-shell.packages ? hello;
+        wheel-required = hello-shell.wheel;
+        wheel-allowed = environment.wheel;
+        operator-shell =
+          let
+            operator = (environment.apply resources).operator;
+          in
+          {
+            inherit (operator) isNormalUser;
+            packages = map (p: "${p.pname}") operator.packages;
+            extraGroups = operator.extraGroups;
+          };
+        deployment = {
+          inherit (result) _type;
+          isModule = lib.isFunction fediversity.deployments.example.deployment;
+          deploymentFunction = lib.isFunction result.deploymentFunction;
+          getProviders = lib.isFunction result.getProviders;
+        };
       };
     expected = {
+      number-of-resources = 1;
       example-configuration = {
         enable = true;
         applications.hello.enable = true;
       };
+      hello-package-exists = true;
+      wheel-required = false;
+      wheel-allowed = false;
+      operator-shell = {
+        isNormalUser = true;
+        packages = [ "hello" ];
+        extraGroups = [ ];
+      };
+      deployment = {
+        _type = "nixops4Deployment";
+        deploymentFunction = true;
+        getProviders = true;
+        isModule = false;
+      };
     };
   };
 }

deployment/data-model.nix

@@ -1,6 +1,8 @@
 {
   lib,
   config,
+  options,
+  inputs,
   ...
 }:
 let
@@ -14,20 +16,74 @@ let
     functionTo
     ;
 
-  functionType = import ./function.nix;
-  application-resources = {
+  functionType = import ./function.nix { inherit lib; };
+  application-resources = submodule {
     options.resources = mkOption {
       # TODO: maybe transpose, and group the resources by type instead
       type = attrsOf (
-        attrTag (lib.mapAttrs (_name: resource: mkOption { type = resource.request; }) config.resources)
+        attrTag (
+          lib.mapAttrs (_name: resource: mkOption { type = submodule resource.request; }) config.resources
+        )
       );
     };
   };
+  nixops4Deployment = types.deferredModuleWith {
+    staticModules = [
+      inputs.nixops4.modules.nixops4Deployment.default
+
+      {
+        _class = "nixops4Deployment";
+        _module.args = {
+          resourceProviderSystem = builtins.currentSystem;
+          resources = { };
+        };
+      }
+    ];
+  };
 in
 {
-  _class = "nixops4Deployment";
-
   options = {
+    resources = mkOption {
+      description = "Collection of deployment resources that can be required by applications and policed by hosting providers";
+      type = attrsOf (
+        submodule (
+          { ... }:
+          {
+            _class = "fediversity-resource";
+            options = {
+              description = mkOption {
+                description = "Description of the resource to help application module authors and hosting providers to work with it";
+                type = types.str;
+              };
+              request = mkOption {
+                description = "Options for declaring resource requirements by an application, a description of how the resource is consumed or accessed";
+                type = deferredModuleWith { staticModules = [ { _class = "fediversity-resource-request"; } ]; };
+              };
+              policy = mkOption {
+                description = "Options for configuring the resource policy for the hosting provider, a description of how the resource is made available";
+                type = deferredModuleWith {
+                  staticModules = [
+                    (policy: {
+                      _class = "fediversity-resource-policy";
+                      options.resource-type = mkOption {
+                        description = "The type of resource this policy configures";
+                        type = types.optionType;
+                      };
+                      # TODO(@fricklerhandwerk): we may want to make the function type explict here: `request -> resource-type`
+                      # and then also rename this to be consistent with the application's resource mapping
+                      options.apply = mkOption {
+                        description = "Apply the policy to a request";
+                        type = functionTo policy.config.resource-type;
+                      };
+                    })
+                  ];
+                };
+              };
+            };
+          }
+        )
+      );
+    };
     applications = mkOption {
       description = "Collection of Fediversity applications";
       type = attrsOf (
@@ -46,18 +102,13 @@ in
               description = "Mapping of application configuration to deployment resources, a description of what an application needs to run";
               type = application.config.config-mapping.function-type;
             };
-            resources = mkOption {
-              description = "Compute resources required by an application";
-              type = functionTo application.config.config-mapping.output-type;
-              readOnly = true;
-              default = input: (application.config.implementation input).output;
-            };
+            # TODO(@fricklerhandwerk): this needs a better name, it's just the type
             config-mapping = mkOption {
               description = "Function type for the mapping from application configuration to required resources";
-              type = submodule functionType;
+              type = functionType;
               readOnly = true;
               default = {
-                input-type = application.config.module;
+                input-type = submodule application.config.module;
                 output-type = application-resources;
               };
             };
@@ -65,11 +116,47 @@ in
         })
       );
     };
+    environments = mkOption {
+      description = "Run-time environments for Fediversity applications to be deployed to";
+      type = attrsOf (
+        submodule (environment: {
+          _class = "fediversity-environment";
+          options = {
+            resources = mkOption {
+              description = ''
+                Resources made available by the hosting provider, and their policies.
+
+                Setting this is optional, but provides a place to declare that information for programmatic use in the resource mapping.
+              '';
+              # TODO: maybe transpose, and group the resources by type instead
+              type = attrsOf (
+                attrTag (
+                  lib.mapAttrs (_name: resource: mkOption { type = submodule resource.policy; }) config.resources
+                )
+              );
+            };
+            implementation = mkOption {
+              description = "Mapping of resources required by applications to available resources; the result can be deployed";
+              type = environment.config.resource-mapping.function-type;
+            };
+            resource-mapping = mkOption {
+              description = "Function type for the mapping from resources to a (NixOps4) deployment";
+              type = functionType;
+              # readOnly = true;
+              default = {
+                input-type = application-resources;
+                output-type = nixops4Deployment;
+              };
+            };
+          };
+        })
+      );
+    };
     configuration = mkOption {
       description = "Configuration type declaring options to be set by operators";
       type = optionType;
       readOnly = true;
-      default = submodule {
+      default = submodule (configuration: {
         options = {
           enable = lib.mkEnableOption {
             description = "your Fediversity configuration";
@@ -82,8 +169,55 @@ in
               default = { };
             }
           ) config.applications;
+          required-resources = mkOption {
+            description = "The deployment's required resources by application";
+            type = submodule {
+              options = lib.mapAttrs (
+                name: _application:
+                mkOption {
+                  description = "Resources required for ${name}";
+                  type = config.applications.${name}.config-mapping.output-type;
+                }
+              ) config.applications;
+            };
+            readOnly = true;
+            default = lib.mapAttrs (
+              # FIXME: in nix-unit invoking the implementation somehow triggers an infinite recursion,
+              # tho my trace statements so far got triggered just once
+              name: application-settings: (config.applications.${name}.implementation application-settings).output
+            ) configuration.config.applications;
+          };
         };
-      };
+      });
+    };
+    deployments = mkOption {
+      description = "Deployment of a configuration of applications to a run-time environment.";
+      type = attrsOf (
+        submodule (deployment: {
+          options = {
+            configuration = mkOption {
+              description = "Configuration to be deployed";
+              type = config.configuration;
+            };
+            environment = mkOption {
+              description = "The run-time environment to deploy to";
+              type = options.environments.type.nestedTypes.elemType;
+            };
+            # TODO(@fricklerhandwerk): maybe this should be a separate thing such as `fediversity-setup`,
+            # which makes explicit which applications and environments are available.
+            # then the deployments can simply be the result of the function application baked into this module.
+            deployment = mkOption {
+              description = "Generate a deployment from a configuration, by applying an environment's resource policies to the applications' resource mappings";
+              type = deployment.config.environment.resource-mapping.output-type;
+              readOnly = true;
+              # TODO: check cfg.enable.true
+              default =
+                (deployment.config.environment.implementation deployment.config.configuration.required-resources)
+                .output;
+            };
+          };
+        })
+      );
     };
   };
 }

deployment/function.nix

@@ -1,37 +1,36 @@
 /**
   Modular function type
 */
-{ config, lib, ... }:
+{ lib, ... }:
 let
   inherit (lib) mkOption types;
   inherit (types)
-    deferredModule
     submodule
     functionTo
     optionType
     ;
 in
-{
+submodule (function: {
   options = {
     input-type = mkOption {
-      type = deferredModule;
+      type = optionType;
     };
     output-type = mkOption {
-      type = deferredModule;
+      type = optionType;
     };
     function-type = mkOption {
       type = optionType;
-      readOnly = true;
+      # readOnly = true;
       default = functionTo (submodule {
         options = {
           input = mkOption {
-            type = submodule config.input-type;
+            type = function.config.input-type;
           };
           output = mkOption {
-            type = submodule config.output-type;
+            type = function.config.output-type;
           };
         };
       });
     };
   };
-}
+})

infra/common/options.nix

@@ -20,16 +20,13 @@ in
       '';
     };
 
-    proxmox = mkOption {
-      type = types.nullOr (
-        types.enum [
-          "procolix"
-          "fediversity"
-        ]
-      );
+    isFediversityVm = mkOption {
+      type = types.bool;
       description = ''
-        The Proxmox instance. This is used for provisioning only and should be
-        set to `null` if the machine is not a VM.
+        Whether the machine is a Fediversity VM or not. This is used to
+        determine whether the machine should be provisioned via Proxmox or not.
+        Machines that are _not_ Fediversity VM could be physical machines, or
+        VMs that live outside Fediversity, eg. on Procolix's Proxmox.
       '';
     };
 

infra/common/proxmox-qemu-vm.nix

@@ -1,10 +1,14 @@
-{ sources, ... }:
+{ ... }:
+
 {
   _class = "nixos";
 
-  imports = [
-    "${sources.nixpkgs}/nixos/modules/profiles/qemu-guest.nix"
-  ];
+  ## FIXME: It would be nice, but the following leads to infinite recursion
+  ## in the way we currently plug `sources` in.
+  ##
+  # imports = [
+  #   "${sources.nixpkgs}/nixos/modules/profiles/qemu-guest.nix"
+  # ];
 
   boot = {
     initrd = {

infra/common/resource.nix

@@ -2,7 +2,6 @@
   inputs,
   lib,
   config,
-  sources,
   keys,
   secrets,
   ...
@@ -33,10 +32,9 @@ in
   ## should go into the `./nixos` subdirectory.
   nixos.module = {
     imports = [
-      "${sources.agenix}/modules/age.nix"
-      "${sources.disko}/module.nix"
       ./options.nix
       ./nixos
+      ./proxmox-qemu-vm.nix
     ];
 
     ## Inject the shared options from the resource's `config` into the NixOS

infra/flake-part.nix

@@ -14,90 +14,55 @@ let
     mkOption
     evalModules
     filterAttrs
+    mapAttrs'
+    deepSeq
     ;
   inherit (lib.attrsets) genAttrs;
 
-  ## Given a machine's name and whether it is a test VM, make a resource module,
-  ## except for its missing provider. (Depending on the use of that resource, we
-  ## will provide a different one.)
-  makeResourceModule =
-    { vmName, isTestVm }:
-    {
-      nixos.module.imports = [
-        ./common/proxmox-qemu-vm.nix
-      ];
-
-      nixos.specialArgs = {
-        inherit
-          sources
-          inputs
-          keys
-          secrets
-          ;
-      };
-
-      imports =
-        [
-          ./common/resource.nix
-        ]
-        ++ (
-          if isTestVm then
-            [
-              ../machines/operator/${vmName}
-              {
-                nixos.module.users.users.root.openssh.authorizedKeys.keys = [
-                  # allow our panel vm access to the test machines
-                  keys.panel
-                ];
-              }
-            ]
-          else
-            [
-              ../machines/dev/${vmName}
-            ]
-        );
-      fediversityVm.name = vmName;
+  commonResourceModule = {
+    # TODO(@fricklerhandwerk): this is terrible but IMO we should just ditch
+    # flake-parts and have our own data model for how the project is organised
+    # internally
+    _module.args = {
+      inherit
+        inputs
+        keys
+        secrets
+        sources
+        ;
     };
 
+    ## FIXME: It would be preferrable to have those `sources`-related imports in
+    ## the modules that use them. However, doing so triggers infinite recursions
+    ## because of the way we propagate `sources`. `sources` must be propagated by
+    ## means of `specialArgs`, but this requires a bigger change.
+    nixos.module.imports = [
+      "${sources.nixpkgs}/nixos/modules/profiles/qemu-guest.nix"
+      "${sources.agenix}/modules/age.nix"
+      "${sources.disko}/module.nix"
+      "${sources.home-manager}/nixos"
+    ];
+
+    imports = [
+      ./common/resource.nix
+    ];
+  };
+
   ## Given a list of machine names, make a deployment with those machines'
   ## configurations as resources.
   makeDeployment =
     vmNames:
     { providers, ... }:
     {
-      # XXX: this type merge is for adding `specialArgs` to resource modules
-      options.resources = mkOption {
-        type =
-          with lib.types;
-          lazyAttrsOf (submoduleWith {
-            class = "nixops4Resource";
-            modules = [ ];
-            # TODO(@fricklerhandwerk): we may want to pass through all of `specialArgs`
-            # once we're sure it's sane. leaving it here for better control during refactoring.
-            specialArgs = {
-              inherit
-                sources
-                inputs
-                keys
-                secrets
-
-                ;
-            };
-          });
-      };
-      config = {
-        providers.local = inputs.nixops4.modules.nixops4Provider.local;
-        resources = genAttrs vmNames (vmName: {
-          type = providers.local.exec;
-          imports = [
-            inputs.nixops4-nixos.modules.nixops4Resource.nixos
-            (makeResourceModule {
-              inherit vmName;
-              isTestVm = false;
-            })
-          ];
-        });
-      };
+      providers.local = inputs.nixops4.modules.nixops4Provider.local;
+      resources = genAttrs vmNames (vmName: {
+        type = providers.local.exec;
+        imports = [
+          inputs.nixops4-nixos.modules.nixops4Resource.nixos
+          commonResourceModule
+          ../machines/dev/${vmName}
+        ];
+      });
     };
   makeDeployment' = vmName: makeDeployment [ vmName ];
 
@@ -112,21 +77,29 @@ let
         fediversity = import ../services/fediversity;
       }
       {
-        garageConfigurationResource = makeResourceModule {
-          vmName = "test01";
-          isTestVm = true;
+        garageConfigurationResource = {
+          imports = [
+            commonResourceModule
+            ../machines/operator/test01
+          ];
         };
-        mastodonConfigurationResource = makeResourceModule {
-          vmName = "test06"; # somehow `test02` has a problem - use test06 instead
-          isTestVm = true;
+        mastodonConfigurationResource = {
+          imports = [
+            commonResourceModule
+            ../machines/operator/test06 # somehow `test02` has a problem - use test06 instead
+          ];
         };
-        peertubeConfigurationResource = makeResourceModule {
-          vmName = "test05";
-          isTestVm = true;
+        peertubeConfigurationResource = {
+          imports = [
+            commonResourceModule
+            ../machines/operator/test05
+          ];
         };
-        pixelfedConfigurationResource = makeResourceModule {
-          vmName = "test04";
-          isTestVm = true;
+        pixelfedConfigurationResource = {
+          imports = [
+            commonResourceModule
+            ../machines/operator/test04
+          ];
         };
       };
 
@@ -139,54 +112,63 @@ let
     ## this is only needed to expose NixOS configurations for provisioning
     ## purposes, and eventually all of this should be handled by NixOps4.
     options = {
-      nixos.module = mkOption { }; # NOTE: not just `nixos` otherwise merging will go wrong
+      nixos.module = mkOption { type = lib.types.deferredModule; }; # NOTE: not just `nixos` otherwise merging will go wrong
       nixpkgs = mkOption { };
       ssh = mkOption { };
     };
   };
 
   makeResourceConfig =
-    vm:
+    { vmName, isTestVm }:
     (evalModules {
       modules = [
         nixops4ResourceNixosMockOptions
-        (makeResourceModule vm)
+        commonResourceModule
+        (if isTestVm then ../machines/operator/${vmName} else ../machines/dev/${vmName})
       ];
     }).config;
 
   ## Given a VM name, make a NixOS configuration for this machine.
   makeConfiguration =
     isTestVm: vmName:
-    let
-      inherit (sources) nixpkgs;
-    in
-    import "${nixpkgs}/nixos" {
-      modules = [
-        (makeResourceConfig { inherit vmName isTestVm; }).nixos.module
-      ];
+    import "${sources.nixpkgs}/nixos" {
+      configuration = (makeResourceConfig { inherit vmName isTestVm; }).nixos.module;
+      system = "x86_64-linux";
     };
 
-  makeVmOptions = isTestVm: vmName: {
-    inherit ((makeResourceConfig { inherit vmName isTestVm; }).fediversityVm)
-      proxmox
-      vmId
-      description
-
-      sockets
-      cores
-      memory
-      diskSize
-
-      hostPublicKey
-      unsafeHostPrivateKey
-      ;
-  };
+  makeVmOptions =
+    isTestVm: vmName:
+    let
+      config = (makeResourceConfig { inherit vmName isTestVm; }).fediversityVm;
+    in
+    if config.isFediversityVm then
+      {
+        inherit (config)
+          vmId
+          description
+          sockets
+          cores
+          memory
+          diskSize
+          hostPublicKey
+          unsafeHostPrivateKey
+          ;
+      }
+    else
+      null;
 
   listSubdirectories = path: attrNames (filterAttrs (_: type: type == "directory") (readDir path));
 
   machines = listSubdirectories ../machines/dev;
   testMachines = listSubdirectories ../machines/operator;
 
+  nixosConfigurations =
+    genAttrs machines (makeConfiguration false)
+    // genAttrs testMachines (makeConfiguration true);
+  vmOptions =
+    filterAttrs (_: value: value != null) # Filter out non-Fediversity VMs
+      (genAttrs machines (makeVmOptions false) // genAttrs testMachines (makeVmOptions true));
+
 in
 {
   _class = "flake";
@@ -210,10 +192,23 @@ in
       )
     );
   };
-  flake.nixosConfigurations =
-    genAttrs machines (makeConfiguration false)
-    // genAttrs testMachines (makeConfiguration true);
-  flake.vmOptions =
-    genAttrs machines (makeVmOptions false)
-    // genAttrs testMachines (makeVmOptions true);
+  flake = { inherit nixosConfigurations vmOptions; };
+
+  perSystem =
+    { pkgs, ... }:
+    {
+      checks =
+        mapAttrs' (name: nixosConfiguration: {
+          name = "nixosConfigurations-${name}";
+          value = nixosConfiguration.config.system.build.toplevel;
+        }) nixosConfigurations
+        // mapAttrs' (name: vmOptions: {
+          name = "vmOptions-${name}";
+          ## Check that VM options builds/evaluates correctly. `deepSeq e1
+          ## e2` evaluates `e1` strictly in depth before returning `e2`. We
+          ## use this trick because checks need to be derivations, which VM
+          ## options are not.
+          value = deepSeq vmOptions pkgs.hello;
+        }) vmOptions;
+    };
 }

infra/proxmox-provision.sh

@@ -179,15 +179,9 @@ grab_vm_options () {
     --log-format raw --quiet
   )
 
-  proxmox=$(echo "$options" | jq -r .proxmox)
   vm_id=$(echo "$options" | jq -r .vmId)
   description=$(echo "$options" | jq -r .description)
 
-  if [ "$proxmox" != fediversity ]; then
-    die "I do not know how to provision things that are not Fediversity VMs,
-but I got proxmox = '%s' for VM %s." "$proxmox" "$vm_name"
-  fi
-
   sockets=$(echo "$options" | jq -r .sockets)
   cores=$(echo "$options" | jq -r .cores)
   memory=$(echo "$options" | jq -r .memory)

infra/proxmox-remove.sh

@@ -167,16 +167,10 @@ grab_vm_options () {
       --log-format raw --quiet
     )
 
-    proxmox=$(echo "$options" | jq -r .proxmox)
     vm_id=$(echo "$options" | jq -r .vmId)
 
-    if [ "$proxmox" != fediversity ]; then
-      die "I do not know how to remove things that are not Fediversity VMs,
-  but I got proxmox = '%s' for VM %s." "$proxmox" "$vm_name"
-    fi
-
-    printf 'done grabing VM options for VM %s. Found VM %d on %s Proxmox.\n' \
-      "$vm_name" "$vm_id" "$proxmox"
+    printf 'done grabing VM options for VM %s. Got id: %d.\n' \
+      "$vm_name" "$vm_id"
   fi
 }
 

machines/dev/fedi200/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "fedi200";
+    isFediversityVm = true;
     vmId = 200;
-    proxmox = "fediversity";
     description = "Testing machine for Hans";
 
     domain = "abundos.eu";
@@ -16,10 +17,4 @@
       gateway = "2a00:51c0:13:1305::1";
     };
   };
-
-  nixos.module = {
-    imports = [
-      ../../../infra/common/proxmox-qemu-vm.nix
-    ];
-  };
 }

machines/dev/fedi201/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "fedi201";
+    isFediversityVm = true;
     vmId = 201;
-    proxmox = "fediversity";
     description = "FediPanel";
 
     domain = "abundos.eu";
@@ -19,7 +20,6 @@
 
   nixos.module = {
     imports = [
-      ../../../infra/common/proxmox-qemu-vm.nix
       ./fedipanel.nix
     ];
   };

machines/dev/fedi201/fedipanel.nix

@@ -1,6 +1,5 @@
 {
   config,
-  sources,
   ...
 }:
 let
@@ -11,7 +10,6 @@ in
 
   imports = [
     (import ../../../panel { }).module
-    "${sources.home-manager}/nixos"
   ];
 
   security.acme = {

machines/dev/forgejo-ci/default.nix

@@ -20,7 +20,9 @@ in
   ssh.host = mkForce "forgejo-ci";
 
   fediversityVm = {
+    name = "forgejo-ci";
     domain = "procolix.com";
+    isFediversityVm = false;
 
     ipv4 = {
       interface = "enp1s0f0";

machines/dev/vm02116/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "vm02116";
+    isFediversityVm = false;
     vmId = 2116;
-    proxmox = "procolix";
     description = "Forgejo";
 
     ipv4.address = "185.206.232.34";
@@ -14,7 +15,6 @@
     { lib, ... }:
     {
       imports = [
-        ../../../infra/common/proxmox-qemu-vm.nix
         ./forgejo.nix
       ];
 

machines/dev/vm02187/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "vm02187";
+    isFediversityVm = false;
     vmId = 2187;
-    proxmox = "procolix";
     description = "Wiki";
 
     ipv4.address = "185.206.232.187";
@@ -14,7 +15,6 @@
     { lib, ... }:
     {
       imports = [
-        ../../../infra/common/proxmox-qemu-vm.nix
         ./wiki.nix
       ];
 

machines/operator/test01/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test01";
+    isFediversityVm = true;
     vmId = 7001;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test02/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test02";
+    isFediversityVm = true;
     vmId = 7002;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test03/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test03";
+    isFediversityVm = true;
     vmId = 7003;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test04/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test04";
+    isFediversityVm = true;
     vmId = 7004;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test05/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test05";
+    isFediversityVm = true;
     vmId = 7005;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test06/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test06";
+    isFediversityVm = true;
     vmId = 7006;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test11/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test11";
+    isFediversityVm = true;
     vmId = 7011;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test12/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test12";
+    isFediversityVm = true;
     vmId = 7012;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test13/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test13";
+    isFediversityVm = true;
     vmId = 7013;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;

machines/operator/test14/default.nix

@@ -2,8 +2,9 @@
   _class = "nixops4Resource";
 
   fediversityVm = {
+    name = "test14";
+    isFediversityVm = true;
     vmId = 7014;
-    proxmox = "fediversity";
 
     hostPublicKey = builtins.readFile ./ssh_host_ed25519_key.pub;
     unsafeHostPrivateKey = builtins.readFile ./ssh_host_ed25519_key;