{ lib }: let inherit (lib) all any attrByPath attrNames catAttrs concatLists concatMap count elem filter findFirst flip foldl foldl' getAttrFromPath head id imap1 isAttrs isBool isFunction isList isString length mapAttrs mapAttrsToList mapAttrsRecursiveCond min optional optionalAttrs optionalString recursiveUpdate reverseList sort setAttrByPath toList types warnIf ; inherit (lib.options) isOption mkOption showDefs showFiles showOption unknownModule ; in rec { /* Evaluate a set of modules. The result is a set of two attributes: ‘options’: the nested set of all option declarations, and ‘config’: the nested set of all option values. !!! Please think twice before adding to this argument list! The more that is specified here instead of in the modules themselves the harder it is to transparently move a set of modules to be a submodule of another config (as the proper arguments need to be replicated at each call to evalModules) and the less declarative the module set is. */ evalModules = { modules , prefix ? [] , # This should only be used for special arguments that need to be evaluated # when resolving module structure (like in imports). For everything else, # there's _module.args. If specialArgs.modulesPath is defined it will be # used as the base path for disabledModules. specialArgs ? {} , # This would be remove in the future, Prefer _module.args option instead. args ? {} , # This would be remove in the future, Prefer _module.check option instead. check ? true }: let # This internal module declare internal options under the `_module' # attribute. These options are fragile, as they are used by the # module system to change the interpretation of modules. internalModule = rec { _file = ./modules.nix; key = _file; options = { _module.args = mkOption { # Because things like `mkIf` are entirely useless for # `_module.args` (because there's no way modules can check which # arguments were passed), we'll use `lazyAttrsOf` which drops # support for that, in turn it's lazy in its values. This means e.g. # a `_module.args.pkgs = import (fetchTarball { ... }) {}` won't # start a download when `pkgs` wasn't evaluated. type = types.lazyAttrsOf types.unspecified; internal = true; description = "Arguments passed to each module."; }; _module.check = mkOption { type = types.bool; internal = true; default = check; description = "Whether to check whether all option definitions have matching declarations."; }; _module.freeformType = mkOption { # Disallow merging for now, but could be implemented nicely with a `types.optionType` type = types.nullOr (types.uniq types.attrs); internal = true; default = null; description = '' If set, merge all definitions that don't have an associated option together using this type. The result then gets combined with the values of all declared options to produce the final config value. If this is null, definitions without an option will throw an error unless is turned off. ''; }; }; config = { _module.args = args; }; }; merged = let collected = collectModules (specialArgs.modulesPath or "") (modules ++ [ internalModule ]) ({ inherit lib options config specialArgs; } // specialArgs); in mergeModules prefix (reverseList collected); options = merged.matchedOptions; config = let # For definitions that have an associated option declaredConfig = mapAttrsRecursiveCond (v: ! isOption v) (_: v: v.value) options; # If freeformType is set, this is for definitions that don't have an associated option freeformConfig = let defs = map (def: { file = def.file; value = setAttrByPath def.prefix def.value; }) merged.unmatchedDefns; in if defs == [] then {} else declaredConfig._module.freeformType.merge prefix defs; in if declaredConfig._module.freeformType == null then declaredConfig # Because all definitions that had an associated option ended in # declaredConfig, freeformConfig can only contain the non-option # paths, meaning recursiveUpdate will never override any value else recursiveUpdate freeformConfig declaredConfig; checkUnmatched = if config._module.check && config._module.freeformType == null && merged.unmatchedDefns != [] then let firstDef = head merged.unmatchedDefns; baseMsg = "The option `${showOption (prefix ++ firstDef.prefix)}' does not exist. Definition values:${showDefs [ firstDef ]}"; in if attrNames options == [ "_module" ] then throw '' ${baseMsg} However there are no options defined in `${showOption prefix}'. Are you sure you've declared your options properly? This can happen if you e.g. declared your options in `types.submodule' under `config' rather than `options'. '' else throw baseMsg else null; result = builtins.seq checkUnmatched { inherit options; config = removeAttrs config [ "_module" ]; inherit (config) _module; }; in result; # collectModules :: (modulesPath: String) -> (modules: [ Module ]) -> (args: Attrs) -> [ Module ] # # Collects all modules recursively through `import` statements, filtering out # all modules in disabledModules. collectModules = let # Like unifyModuleSyntax, but also imports paths and calls functions if necessary loadModule = args: fallbackFile: fallbackKey: m: if isFunction m || isAttrs m then unifyModuleSyntax fallbackFile fallbackKey (applyIfFunction fallbackKey m args) else if isList m then let defs = [{ file = fallbackFile; value = m; }]; in throw "Module imports can't be nested lists. Perhaps you meant to remove one level of lists? Definitions: ${showDefs defs}" else unifyModuleSyntax (toString m) (toString m) (applyIfFunction (toString m) (import m) args); /* Collects all modules recursively into the form { disabled = [ ]; # All modules of the main module list modules = [ { key = ; module = ; # All modules imported by the module for key1 modules = [ { key = ; module = ; # All modules imported by the module for key1-1 modules = [ ... ]; } ... ]; } ... ]; } */ collectStructuredModules = let collectResults = modules: { disabled = concatLists (catAttrs "disabled" modules); inherit modules; }; in parentFile: parentKey: initialModules: args: collectResults (imap1 (n: x: let module = loadModule args parentFile "${parentKey}:anon-${toString n}" x; collectedImports = collectStructuredModules module._file module.key module.imports args; in { key = module.key; module = module; modules = collectedImports.modules; disabled = module.disabledModules ++ collectedImports.disabled; }) initialModules); # filterModules :: String -> { disabled, modules } -> [ Module ] # # Filters a structure as emitted by collectStructuredModules by removing all disabled # modules recursively. It returns the final list of unique-by-key modules filterModules = modulesPath: { disabled, modules }: let moduleKey = m: if isString m then toString modulesPath + "/" + m else toString m; disabledKeys = map moduleKey disabled; keyFilter = filter (attrs: ! elem attrs.key disabledKeys); in map (attrs: attrs.module) (builtins.genericClosure { startSet = keyFilter modules; operator = attrs: keyFilter attrs.modules; }); in modulesPath: initialModules: args: filterModules modulesPath (collectStructuredModules unknownModule "" initialModules args); /* Massage a module into canonical form, that is, a set consisting of ‘options’, ‘config’ and ‘imports’ attributes. */ unifyModuleSyntax = file: key: m: let addMeta = config: if m ? meta then mkMerge [ config { meta = m.meta; } ] else config; addFreeformType = config: if m ? freeformType then mkMerge [ config { _module.freeformType = m.freeformType; } ] else config; in if m ? config || m ? options then let badAttrs = removeAttrs m ["_file" "key" "disabledModules" "imports" "options" "config" "meta" "freeformType"]; in if badAttrs != {} then throw "Module `${key}' has an unsupported attribute `${head (attrNames badAttrs)}'. This is caused by introducing a top-level `config' or `options' attribute. Add configuration attributes immediately on the top level instead, or move all of them (namely: ${toString (attrNames badAttrs)}) into the explicit `config' attribute." else { _file = toString m._file or file; key = toString m.key or key; disabledModules = m.disabledModules or []; imports = m.imports or []; options = m.options or {}; config = addFreeformType (addMeta (m.config or {})); } else { _file = toString m._file or file; key = toString m.key or key; disabledModules = m.disabledModules or []; imports = m.require or [] ++ m.imports or []; options = {}; config = addFreeformType (addMeta (removeAttrs m ["_file" "key" "disabledModules" "require" "imports" "freeformType"])); }; applyIfFunction = key: f: args@{ config, options, lib, ... }: if isFunction f then let # Module arguments are resolved in a strict manner when attribute set # deconstruction is used. As the arguments are now defined with the # config._module.args option, the strictness used on the attribute # set argument would cause an infinite loop, if the result of the # option is given as argument. # # To work-around the strictness issue on the deconstruction of the # attributes set argument, we create a new attribute set which is # constructed to satisfy the expected set of attributes. Thus calling # a module will resolve strictly the attributes used as argument but # not their values. The values are forwarding the result of the # evaluation of the option. context = name: ''while evaluating the module argument `${name}' in "${key}":''; extraArgs = builtins.mapAttrs (name: _: builtins.addErrorContext (context name) (args.${name} or config._module.args.${name}) ) (lib.functionArgs f); # Note: we append in the opposite order such that we can add an error # context on the explicited arguments of "args" too. This update # operator is used to make the "args@{ ... }: with args.lib;" notation # works. in f (args // extraArgs) else f; /* Merge a list of modules. This will recurse over the option declarations in all modules, combining them into a single set. At the same time, for each option declaration, it will merge the corresponding option definitions in all machines, returning them in the ‘value’ attribute of each option. This returns a set like { # A recursive set of options along with their final values matchedOptions = { foo = { _type = "option"; value = "option value of foo"; ... }; bar.baz = { _type = "option"; value = "option value of bar.baz"; ... }; ... }; # A list of definitions that weren't matched by any option unmatchedDefns = [ { file = "file.nix"; prefix = [ "qux" ]; value = "qux"; } ... ]; } */ mergeModules = prefix: modules: mergeModules' prefix modules (concatMap (m: map (config: { file = m._file; inherit config; }) (pushDownProperties m.config)) modules); mergeModules' = prefix: options: configs: let /* byName is like foldAttrs, but will look for attributes to merge in the specified attribute name. byName "foo" (module: value: ["module.hidden=${module.hidden},value=${value}"]) [ { hidden="baz"; foo={qux="bar"; gla="flop";}; } { hidden="fli"; foo={qux="gne"; gli="flip";}; } ] ===> { gla = [ "module.hidden=baz,value=flop" ]; gli = [ "module.hidden=fli,value=flip" ]; qux = [ "module.hidden=baz,value=bar" "module.hidden=fli,value=gne" ]; } */ byName = attr: f: modules: foldl' (acc: module: if !(builtins.isAttrs module.${attr}) then throw '' You're trying to declare a value of type `${builtins.typeOf module.${attr}}' rather than an attribute-set for the option `${builtins.concatStringsSep "." prefix}'! This usually happens if `${builtins.concatStringsSep "." prefix}' has option definitions inside that are not matched. Please check how to properly define this option by e.g. referring to `man 5 configuration.nix'! '' else acc // (mapAttrs (n: v: (acc.${n} or []) ++ f module v ) module.${attr} ) ) {} modules; # an attrset 'name' => list of submodules that declare ‘name’. declsByName = byName "options" (module: option: [{ inherit (module) _file; options = option; }] ) options; # an attrset 'name' => list of submodules that define ‘name’. defnsByName = byName "config" (module: value: map (config: { inherit (module) file; inherit config; }) (pushDownProperties value) ) configs; # extract the definitions for each loc defnsByName' = byName "config" (module: value: [{ inherit (module) file; inherit value; }] ) configs; resultsByName = flip mapAttrs declsByName (name: decls: # We're descending into attribute ‘name’. let loc = prefix ++ [name]; defns = defnsByName.${name} or []; defns' = defnsByName'.${name} or []; nrOptions = count (m: isOption m.options) decls; in if nrOptions == length decls then let opt = fixupOptionType loc (mergeOptionDecls loc decls); in { matchedOptions = evalOptionValue loc opt defns'; unmatchedDefns = []; } else if nrOptions != 0 then let firstOption = findFirst (m: isOption m.options) "" decls; firstNonOption = findFirst (m: !isOption m.options) "" decls; in throw "The option `${showOption loc}' in `${firstOption._file}' is a prefix of options in `${firstNonOption._file}'." else mergeModules' loc decls defns); matchedOptions = mapAttrs (n: v: v.matchedOptions) resultsByName; # an attrset 'name' => list of unmatched definitions for 'name' unmatchedDefnsByName = # Propagate all unmatched definitions from nested option sets mapAttrs (n: v: v.unmatchedDefns) resultsByName # Plus the definitions for the current prefix that don't have a matching option // removeAttrs defnsByName' (attrNames matchedOptions); in { inherit matchedOptions; # Transforms unmatchedDefnsByName into a list of definitions unmatchedDefns = concatLists (mapAttrsToList (name: defs: map (def: def // { # Set this so we know when the definition first left unmatched territory prefix = [name] ++ (def.prefix or []); }) defs ) unmatchedDefnsByName); }; /* Merge multiple option declarations into a single declaration. In general, there should be only one declaration of each option. The exception is the ‘options’ attribute, which specifies sub-options. These can be specified multiple times to allow one module to add sub-options to an option declared somewhere else (e.g. multiple modules define sub-options for ‘fileSystems’). 'loc' is the list of attribute names where the option is located. 'opts' is a list of modules. Each module has an options attribute which correspond to the definition of 'loc' in 'opt.file'. */ mergeOptionDecls = let packSubmodule = file: m: { _file = file; imports = [ m ]; }; coerceOption = file: opt: if isFunction opt then packSubmodule file opt else packSubmodule file { options = opt; }; in loc: opts: foldl' (res: opt: let t = res.type; t' = opt.options.type; mergedType = t.typeMerge t'.functor; typesMergeable = mergedType != null; typeSet = if (bothHave "type") && typesMergeable then { type = mergedType; } else {}; bothHave = k: opt.options ? ${k} && res ? ${k}; in if bothHave "default" || bothHave "example" || bothHave "description" || bothHave "apply" || (bothHave "type" && (! typesMergeable)) then throw "The option `${showOption loc}' in `${opt._file}' is already declared in ${showFiles res.declarations}." else let /* Add the modules of the current option to the list of modules already collected. The options attribute except either a list of submodules or a submodule. For each submodule, we add the file of the current option declaration as the file use for the submodule. If the submodule defines any filename, then we ignore the enclosing option file. */ options' = toList opt.options.options; getSubModules = opt.options.type.getSubModules or null; submodules = if getSubModules != null then map (packSubmodule opt._file) getSubModules ++ res.options else if opt.options ? options then map (coerceOption opt._file) options' ++ res.options else res.options; in opt.options // res // { declarations = res.declarations ++ [opt._file]; options = submodules; } // typeSet ) { inherit loc; declarations = []; options = []; } opts; /* Merge all the definitions of an option to produce the final config value. */ evalOptionValue = loc: opt: defs: let # Add in the default value for this option, if any. defs' = (optional (opt ? default) { file = head opt.declarations; value = mkOptionDefault opt.default; }) ++ defs; # Handle properties, check types, and merge everything together. res = if opt.readOnly or false && length defs' > 1 then let # For a better error message, evaluate all readOnly definitions as # if they were the only definition. separateDefs = map (def: def // { value = (mergeDefinitions loc opt.type [ def ]).mergedValue; }) defs'; in throw "The option `${showOption loc}' is read-only, but it's set multiple times. Definition values:${showDefs separateDefs}" else mergeDefinitions loc opt.type defs'; # Apply the 'apply' function to the merged value. This allows options to # yield a value computed from the definitions value = if opt ? apply then opt.apply res.mergedValue else res.mergedValue; warnDeprecation = warnIf (opt.type.deprecationMessage != null) "The type `types.${opt.type.name}' of option `${showOption loc}' defined in ${showFiles opt.declarations} is deprecated. ${opt.type.deprecationMessage}"; in warnDeprecation opt // { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value; inherit (res.defsFinal') highestPrio; definitions = map (def: def.value) res.defsFinal; files = map (def: def.file) res.defsFinal; inherit (res) isDefined; }; # Merge definitions of a value of a given type. mergeDefinitions = loc: type: defs: rec { defsFinal' = let # Process mkMerge and mkIf properties. defs' = concatMap (m: map (value: { inherit (m) file; inherit value; }) (builtins.addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value)) ) defs; # Process mkOverride properties. defs'' = filterOverrides' defs'; # Sort mkOrder properties. defs''' = # Avoid sorting if we don't have to. if any (def: def.value._type or "" == "order") defs''.values then sortProperties defs''.values else defs''.values; in { values = defs'''; inherit (defs'') highestPrio; }; defsFinal = defsFinal'.values; # Type-check the remaining definitions, and merge them. Or throw if no definitions. mergedValue = if isDefined then if all (def: type.check def.value) defsFinal then type.merge loc defsFinal else let allInvalid = filter (def: ! type.check def.value) defsFinal; in throw "A definition for option `${showOption loc}' is not of type `${type.description}'. Definition values:${showDefs allInvalid}" else # (nixos-option detects this specific error message and gives it special # handling. If changed here, please change it there too.) throw "The option `${showOption loc}' is used but not defined."; isDefined = defsFinal != []; optionalValue = if isDefined then { value = mergedValue; } else {}; }; /* Given a config set, expand mkMerge properties, and push down the other properties into the children. The result is a list of config sets that do not have properties at top-level. For example, mkMerge [ { boot = set1; } (mkIf cond { boot = set2; services = set3; }) ] is transformed into [ { boot = set1; } { boot = mkIf cond set2; services = mkIf cond set3; } ]. This transform is the critical step that allows mkIf conditions to refer to the full configuration without creating an infinite recursion. */ pushDownProperties = cfg: if cfg._type or "" == "merge" then concatMap pushDownProperties cfg.contents else if cfg._type or "" == "if" then map (mapAttrs (n: v: mkIf cfg.condition v)) (pushDownProperties cfg.content) else if cfg._type or "" == "override" then map (mapAttrs (n: v: mkOverride cfg.priority v)) (pushDownProperties cfg.content) else # FIXME: handle mkOrder? [ cfg ]; /* Given a config value, expand mkMerge properties, and discharge any mkIf conditions. That is, this is the place where mkIf conditions are actually evaluated. The result is a list of config values. For example, ‘mkIf false x’ yields ‘[]’, ‘mkIf true x’ yields ‘[x]’, and mkMerge [ 1 (mkIf true 2) (mkIf true (mkIf false 3)) ] yields ‘[ 1 2 ]’. */ dischargeProperties = def: if def._type or "" == "merge" then concatMap dischargeProperties def.contents else if def._type or "" == "if" then if isBool def.condition then if def.condition then dischargeProperties def.content else [ ] else throw "‘mkIf’ called with a non-Boolean condition" else [ def ]; /* Given a list of config values, process the mkOverride properties, that is, return the values that have the highest (that is, numerically lowest) priority, and strip the mkOverride properties. For example, [ { file = "/1"; value = mkOverride 10 "a"; } { file = "/2"; value = mkOverride 20 "b"; } { file = "/3"; value = "z"; } { file = "/4"; value = mkOverride 10 "d"; } ] yields [ { file = "/1"; value = "a"; } { file = "/4"; value = "d"; } ] Note that "z" has the default priority 100. */ filterOverrides = defs: (filterOverrides' defs).values; filterOverrides' = defs: let getPrio = def: if def.value._type or "" == "override" then def.value.priority else defaultPriority; highestPrio = foldl' (prio: def: min (getPrio def) prio) 9999 defs; strip = def: if def.value._type or "" == "override" then def // { value = def.value.content; } else def; in { values = concatMap (def: if getPrio def == highestPrio then [(strip def)] else []) defs; inherit highestPrio; }; /* Sort a list of properties. The sort priority of a property is 1000 by default, but can be overridden by wrapping the property using mkOrder. */ sortProperties = defs: let strip = def: if def.value._type or "" == "order" then def // { value = def.value.content; inherit (def.value) priority; } else def; defs' = map strip defs; compare = a: b: (a.priority or 1000) < (b.priority or 1000); in sort compare defs'; /* Hack for backward compatibility: convert options of type optionSet to options of type submodule. FIXME: remove eventually. */ fixupOptionType = loc: opt: let options = opt.options or (throw "Option `${showOption loc}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}."); f = tp: let optionSetIn = type: (tp.name == type) && (tp.functor.wrapped.name == "optionSet"); in if tp.name == "option set" || tp.name == "submodule" then throw "The option ${showOption loc} uses submodules without a wrapping type, in ${showFiles opt.declarations}." else if optionSetIn "attrsOf" then types.attrsOf (types.submodule options) else if optionSetIn "listOf" then types.listOf (types.submodule options) else if optionSetIn "nullOr" then types.nullOr (types.submodule options) else tp; in if opt.type.getSubModules or null == null then opt // { type = f (opt.type or types.unspecified); } else opt // { type = opt.type.substSubModules opt.options; options = []; }; /* Properties. */ mkIf = condition: content: { _type = "if"; inherit condition content; }; mkAssert = assertion: message: content: mkIf (if assertion then true else throw "\nFailed assertion: ${message}") content; mkMerge = contents: { _type = "merge"; inherit contents; }; mkOverride = priority: content: { _type = "override"; inherit priority content; }; mkOptionDefault = mkOverride 1500; # priority of option defaults mkDefault = mkOverride 1000; # used in config sections of non-user modules to set a default mkForce = mkOverride 50; mkVMOverride = mkOverride 10; # used by ‘nixos-rebuild build-vm’ mkStrict = builtins.trace "`mkStrict' is obsolete; use `mkOverride 0' instead." (mkOverride 0); mkFixStrictness = id; # obsolete, no-op mkOrder = priority: content: { _type = "order"; inherit priority content; }; mkBefore = mkOrder 500; mkAfter = mkOrder 1500; # The default priority for things that don't have a priority specified. defaultPriority = 100; # Convenient property used to transfer all definitions and their # properties from one option to another. This property is useful for # renaming options, and also for including properties from another module # system, including sub-modules. # # { config, options, ... }: # # { # # 'bar' might not always be defined in the current module-set. # config.foo.enable = mkAliasDefinitions (options.bar.enable or {}); # # # 'barbaz' has to be defined in the current module-set. # config.foobar.paths = mkAliasDefinitions options.barbaz.paths; # } # # Note, this is different than taking the value of the option and using it # as a definition, as the new definition will not keep the mkOverride / # mkDefault properties of the previous option. # mkAliasDefinitions = mkAliasAndWrapDefinitions id; mkAliasAndWrapDefinitions = wrap: option: mkAliasIfDef option (wrap (mkMerge option.definitions)); # Similar to mkAliasAndWrapDefinitions but copies over the priority from the # option as well. # # If a priority is not set, it assumes a priority of defaultPriority. mkAliasAndWrapDefsWithPriority = wrap: option: let prio = option.highestPrio or defaultPriority; defsWithPrio = map (mkOverride prio) option.definitions; in mkAliasIfDef option (wrap (mkMerge defsWithPrio)); mkAliasIfDef = option: mkIf (isOption option && option.isDefined); /* Compatibility. */ fixMergeModules = modules: args: evalModules { inherit modules args; check = false; }; /* Return a module that causes a warning to be shown if the specified option is defined. For example, mkRemovedOptionModule [ "boot" "loader" "grub" "bootDevice" ] "" causes a assertion if the user defines boot.loader.grub.bootDevice. replacementInstructions is a string that provides instructions on how to achieve the same functionality without the removed option, or alternatively a reasoning why the functionality is not needed. replacementInstructions SHOULD be provided! */ mkRemovedOptionModule = optionName: replacementInstructions: { options, ... }: { options = setAttrByPath optionName (mkOption { visible = false; apply = x: throw "The option `${showOption optionName}' can no longer be used since it's been removed. ${replacementInstructions}"; }); config.assertions = let opt = getAttrFromPath optionName options; in [{ assertion = !opt.isDefined; message = '' The option definition `${showOption optionName}' in ${showFiles opt.files} no longer has any effect; please remove it. ${replacementInstructions} ''; }]; }; /* Return a module that causes a warning to be shown if the specified "from" option is defined; the defined value is however forwarded to the "to" option. This can be used to rename options while providing backward compatibility. For example, mkRenamedOptionModule [ "boot" "copyKernels" ] [ "boot" "loader" "grub" "copyKernels" ] forwards any definitions of boot.copyKernels to boot.loader.grub.copyKernels while printing a warning. This also copies over the priority from the aliased option to the non-aliased option. */ mkRenamedOptionModule = from: to: doRename { inherit from to; visible = false; warn = true; use = builtins.trace "Obsolete option `${showOption from}' is used. It was renamed to `${showOption to}'."; }; /* Return a module that causes a warning to be shown if any of the "from" option is defined; the defined values can be used in the "mergeFn" to set the "to" value. This function can be used to merge multiple options into one that has a different type. "mergeFn" takes the module "config" as a parameter and must return a value of "to" option type. mkMergedOptionModule [ [ "a" "b" "c" ] [ "d" "e" "f" ] ] [ "x" "y" "z" ] (config: let value = p: getAttrFromPath p config; in if (value [ "a" "b" "c" ]) == true then "foo" else if (value [ "d" "e" "f" ]) == true then "bar" else "baz") - options.a.b.c is a removed boolean option - options.d.e.f is a removed boolean option - options.x.y.z is a new str option that combines a.b.c and d.e.f functionality This show a warning if any a.b.c or d.e.f is set, and set the value of x.y.z to the result of the merge function */ mkMergedOptionModule = from: to: mergeFn: { config, options, ... }: { options = foldl recursiveUpdate {} (map (path: setAttrByPath path (mkOption { visible = false; # To use the value in mergeFn without triggering errors default = "_mkMergedOptionModule"; })) from); config = { warnings = filter (x: x != "") (map (f: let val = getAttrFromPath f config; opt = getAttrFromPath f options; in optionalString (val != "_mkMergedOptionModule") "The option `${showOption f}' defined in ${showFiles opt.files} has been changed to `${showOption to}' that has a different type. Please read `${showOption to}' documentation and update your configuration accordingly." ) from); } // setAttrByPath to (mkMerge (optional (any (f: (getAttrFromPath f config) != "_mkMergedOptionModule") from) (mergeFn config))); }; /* Single "from" version of mkMergedOptionModule. Return a module that causes a warning to be shown if the "from" option is defined; the defined value can be used in the "mergeFn" to set the "to" value. This function can be used to change an option into another that has a different type. "mergeFn" takes the module "config" as a parameter and must return a value of "to" option type. mkChangedOptionModule [ "a" "b" "c" ] [ "x" "y" "z" ] (config: let value = getAttrFromPath [ "a" "b" "c" ] config; in if value > 100 then "high" else "normal") - options.a.b.c is a removed int option - options.x.y.z is a new str option that supersedes a.b.c This show a warning if a.b.c is set, and set the value of x.y.z to the result of the change function */ mkChangedOptionModule = from: to: changeFn: mkMergedOptionModule [ from ] to changeFn; /* Like ‘mkRenamedOptionModule’, but doesn't show a warning. */ mkAliasOptionModule = from: to: doRename { inherit from to; visible = true; warn = false; use = id; }; doRename = { from, to, visible, warn, use, withPriority ? true }: { config, options, ... }: let fromOpt = getAttrFromPath from options; toOf = attrByPath to (abort "Renaming error: option `${showOption to}' does not exist."); toType = let opt = attrByPath to {} options; in opt.type or (types.submodule {}); in { options = setAttrByPath from (mkOption { inherit visible; description = "Alias of ."; apply = x: use (toOf config); } // optionalAttrs (toType != null) { type = toType; }); config = mkMerge [ { warnings = optional (warn && fromOpt.isDefined) "The option `${showOption from}' defined in ${showFiles fromOpt.files} has been renamed to `${showOption to}'."; } (if withPriority then mkAliasAndWrapDefsWithPriority (setAttrByPath to) fromOpt else mkAliasAndWrapDefinitions (setAttrByPath to) fromOpt) ]; }; /* Use this function to import a JSON file as NixOS configuration. importJSON -> path -> attrs */ importJSON = file: { _file = file; config = lib.importJSON file; }; /* Use this function to import a TOML file as NixOS configuration. importTOML -> path -> attrs */ importTOML = file: { _file = file; config = lib.importTOML file; }; }