feat: initial istio support

istio/generator.nix

@@ -0,0 +1,323 @@
+{ pkgs ? import <nixpkgs> {}, lib ? pkgs.lib, spec ? ./istio-schema.json }:
+
+with lib;
+
+let
+  gen = rec {
+    mkMerge = values: ''mkMerge [${concatMapStrings (value: "
+      ${value}
+    ") values}]'';
+
+    toNixString = value: if isAttrs value || isList value
+      then builtins.toJSON value
+      else if isString value
+      then ''"${value}"''
+      else if value == null
+      then "null"
+      else builtins.toString value;
+
+    removeEmptyLines = str: concatStringsSep "\n" (filter (l: (builtins.match "(  |)+" l) == null) (splitString "\n" str));
+
+    mkOption = {
+      description ? null,
+      type ? null,
+      default ? null,
+      apply ? null
+    }:  removeEmptyLines ''mkOption {
+          ${optionalString (description != null) "description = ${builtins.toJSON description};"}
+          ${optionalString (type != null) ''type = ${type};''}
+          ${optionalString (default != null) ''default = ${toNixString default};''}
+          ${optionalString (apply != null) ''apply = ${apply};''}
+        }'';
+
+    mkOverride = priority: value:  "mkOverride ${toString priority} ${toNixString value}";
+
+    types = {
+      unspecified = "types.unspecified";
+      str = "types.str";
+      int = "types.int";
+      bool = "types.bool";
+      attrs = "types.attrs";
+      nullOr = val: "(types.nullOr ${val})";
+      attrsOf = val: "(types.attrsOf ${val})";
+      listOf = val: "(types.listOf ${val})";
+      coercedTo = coercedType: coerceFunc: finalType:
+        "(types.coercedTo ${coercedType} ${coerceFunc} ${finalType})";
+      either = val1: val2: "(types.either ${val1} ${val2})";
+      loaOf = type: "(types.loaOf ${type})";
+    };
+
+    hasTypeMapping = def:
+      hasAttr "type" def &&
+      elem def.type ["string" "integer" "boolean"];
+
+    mergeValuesByKey = mergeKey: ''(mergeValuesByKey "${mergeKey}")'';
+
+    mapType = def:
+      if def.type == "string" then
+        if hasAttr "format" def && def.format == "int-or-string"
+        then types.either types.int types.str
+        else types.str
+      else if def.type == "integer" then types.int
+      else if def.type == "number" then types.int
+      else if def.type == "boolean" then types.bool
+      else if def.type == "object" then types.attrs
+      else throw "type ${def.type} not supported";
+
+    submoduleOf = definitions: ref: ''(submoduleOf "${ref}")'';
+
+    submoduleForDefinition = ref: name: kind: group: version:
+      ''(submoduleForDefinition "${ref}" "${name}" "${kind}" "${group}" "${version}")'';
+
+    coerceAttrsOfSubmodulesToListByKey = ref: mergeKey:
+      ''(coerceAttrsOfSubmodulesToListByKey "${ref}" "${mergeKey}")'';
+
+    attrsToList = "values: if values != null then mapAttrsToList (n: v: v) values else values";
+
+    refDefinition = attr: head (tail (tail (splitString "/" attr."$ref")));
+  };
+
+  fixJSON = content: replaceStrings ["\\u"] ["u"] content;
+
+  fetchSpecs = path: builtins.fromJSON (fixJSON (builtins.readFile path));
+
+  genDefinitions = swagger: with gen; (mapAttrs (name: definition:
+    # if $ref is in definition it means it's an alias of other definition
+    if hasAttr "$ref" definition
+    then definitions."${refDefinition definition}"
+
+    else if !(hasAttr "properties" definition)
+    then {
+      type = mapType definition;
+    }
+
+    else {
+      options = mapAttrs (propName: property:
+        let
+          isRequired = elem propName (definition.required or []);
+          requiredOrNot = type: if isRequired then type else types.nullOr type;
+          optionProperties =
+            # if $ref is in property it references other definition,
+            # but if other definition does not have properties, then just take it's type
+            if hasAttr "$ref" property then
+              if hasTypeMapping swagger.definitions.${refDefinition property} then {
+                type = requiredOrNot (mapType swagger.definitions.${refDefinition property});
+              }
+              else {
+                type = requiredOrNot (submoduleOf definitions (refDefinition property));
+              }
+
+            else if !(hasAttr "type" property) then {
+              type = types.unspecified;
+            }
+
+            # if property has an array type
+            else if property.type == "array" then
+
+              # if reference is in items it can reference other type of another
+              # definition
+              if hasAttr "$ref" property.items then
+
+                # if it is a reference to simple type
+                if hasTypeMapping swagger.definitions.${refDefinition property.items}
+                then {
+                  type = requiredOrNot (types.listOf (mapType swagger.definitions.${refDefinition property.items}.type));
+                }
+
+                # if a reference is to complex type
+                else
+                  # if x-kubernetes-patch-merge-key is set then make it an
+                  # attribute set of submodules
+                  if hasAttr "x-kubernetes-patch-merge-key" property
+                  then let
+                    mergeKey = property."x-kubernetes-patch-merge-key";
+                  in {
+                    type = requiredOrNot (coerceAttrsOfSubmodulesToListByKey (refDefinition property.items) mergeKey);
+                    apply = attrsToList;
+                  }
+
+                  # in other case it's a simple list
+                  else {
+                    type = requiredOrNot (types.listOf (submoduleOf definitions (refDefinition property.items)));
+                  }
+
+              # in other case it only references a simple type
+              else {
+                type = requiredOrNot (types.listOf (mapType property.items));
+              }
+
+            else if property.type == "object" && hasAttr "additionalProperties" property
+            then
+              # if it is a reference to simple type
+              if (
+                hasAttr "$ref" property.additionalProperties &&
+                hasTypeMapping swagger.definitions.${refDefinition property.additionalProperties}
+              ) then {
+                type = requiredOrNot (types.attrsOf (mapType swagger.definitions.${refDefinition property.additionalProperties}));
+              }
+
+              else if hasAttr "$ref" property.additionalProperties
+              then {
+                type = requiredOrNot types.attrs;
+              }
+
+              # if is an array
+              else if property.additionalProperties.type == "array"
+              then {
+                type = requiredOrNot (types.loaOf (mapType property.additionalProperties.items));
+              }
+
+              else {
+                type = requiredOrNot (types.attrsOf (mapType property.additionalProperties));
+              }
+
+            # just a simple property
+            else {
+              type = requiredOrNot (mapType property);
+            };
+        in mkOption ({
+          description = property.description or "";
+        } // optionProperties)
+      ) definition.properties;
+      config =
+      let
+        optionalProps = filterAttrs (propName: property:
+          !(elem propName (definition.required or []))
+        ) definition.properties;
+      in mapAttrs (name: property: mkOverride 1002 null) optionalProps;
+    }
+  ) swagger.definitions);
+
+  genResources = swagger: mapAttrsToList (name: property: rec {
+    splittedType = splitString "." (removePrefix "me.snowdrop.istio.api." property.javaType);
+    group = (concatStringsSep "." (take ((length splittedType) - 2) splittedType)) + ".istio.io";
+    kind = removeSuffix "Spec" (last splittedType);
+    version = last (take ((length splittedType) - 1) splittedType);
+    ref = removePrefix "#/definitions/" property."$ref";
+  })
+  (filterAttrs (name: property:
+    hasPrefix "me.snowdrop.istio.api" property.javaType &&
+    hasSuffix "Spec" property.javaType
+  ) swagger.properties);
+
+  swagger = fetchSpecs spec;
+
+  definitions = genDefinitions swagger;
+in pkgs.writeText "gen.nix"
+"# This file was generated with kubenix k8s generator, do not edit
+{lib, config, ... }:
+
+with lib;
+
+let
+  types = lib.types // rec {
+    str = mkOptionType {
+      name = \"str\";
+      description = \"string\";
+      check = isString;
+      merge = mergeEqualOption;
+    };
+
+    # Either value of type `finalType` or `coercedType`, the latter is
+    # converted to `finalType` using `coerceFunc`.
+    coercedTo = coercedType: coerceFunc: finalType:
+    mkOptionType rec {
+      name = \"coercedTo\";
+      description = \"\${finalType.description} or \${coercedType.description}\";
+      check = x: finalType.check x || coercedType.check x;
+      merge = loc: defs:
+        let
+          coerceVal = val:
+            if finalType.check val then val
+            else let
+              coerced = coerceFunc val;
+            in assert finalType.check coerced; coerced;
+
+        in finalType.merge loc (map (def: def // { value = coerceVal def.value; }) defs);
+      getSubOptions = finalType.getSubOptions;
+      getSubModules = finalType.getSubModules;
+      substSubModules = m: coercedTo coercedType coerceFunc (finalType.substSubModules m);
+      typeMerge = t1: t2: null;
+      functor = (defaultFunctor name) // { wrapped = finalType; };
+    };
+  };
+
+  mkOptionDefault = mkOverride 1001;
+
+  extraOptions = {
+    kubenix = {};
+  };
+
+  mergeValuesByKey = mergeKey: values:
+    listToAttrs (map
+      (value: nameValuePair (
+        if isAttrs value.\${mergeKey}
+        then toString value.\${mergeKey}.content
+        else (toString value.\${mergeKey})
+      ) value)
+    values);
+
+  submoduleOf = ref: types.submodule ({name, ...}: {
+    options = definitions.\"\${ref}\".options;
+    config = definitions.\"\${ref}\".config;
+  });
+
+  submoduleWithMergeOf = ref: mergeKey: types.submodule ({name, ...}: let
+    convertName = name:
+      if definitions.\"\${ref}\".options.\${mergeKey}.type == types.int
+      then toInt name
+      else name;
+  in {
+    options = definitions.\"\${ref}\".options;
+    config = definitions.\"\${ref}\".config // {
+      \${mergeKey} = mkOverride 1002 (convertName name);
+    };
+  });
+
+  submoduleForDefinition = ref: resource: kind: group: version:
+    types.submodule ({name, ...}: {
+      options = definitions.\"\${ref}\".options // extraOptions;
+      config = mkMerge ([
+        definitions.\"\${ref}\".config
+        {
+          kind = mkOptionDefault kind;
+          apiVersion = mkOptionDefault version;
+
+          # metdata.name cannot use option default, due deep config
+          metadata.name = mkOptionDefault name;
+        }
+      ] ++ (config.defaults.\${resource} or [])
+        ++ (config.defaults.all or []));
+    });
+
+  coerceAttrsOfSubmodulesToListByKey = ref: mergeKey: (types.coercedTo
+    (types.listOf (submoduleOf ref))
+    (mergeValuesByKey mergeKey)
+    (types.attrsOf (submoduleWithMergeOf ref mergeKey))
+  );
+
+  definitions = {
+    ${concatStrings (mapAttrsToList (name: value: "
+    \"${name}\" = {${optionalString (hasAttr "options" value) "
+      options = {${concatStrings (mapAttrsToList (name: value: "
+        \"${name}\" = ${value};
+      ") value.options)}};
+    "}${optionalString (hasAttr "config" value) "
+      config = {${concatStrings (mapAttrsToList (name: value: "
+        \"${name}\" = ${value};
+      ") value.config)}};
+    "}};
+    ") definitions)}
+  };
+in {
+  kubernetes.customResources = [
+  ${concatMapStrings (resource: ''{
+    group = "${resource.group}";
+    version = "${resource.version}";
+    kind = "${resource.kind}";
+    description = "";
+    module = definitions."${resource.ref}";
+  }'') (genResources swagger)}
+  ];
+}
+"