11 files changed, 1258 insertions, 0 deletions
diff --git a/tools/cru-py/cru/__init__.py b/tools/cru-py/cru/__init__.py
new file mode 100644
index 0000000..e36a778
--- /dev/null
+++ b/tools/cru-py/cru/__init__.py
@@ -0,0 +1,12 @@
+import sys
+
+
+class CruInitError(Exception):
+    pass
+
+def check_python_version(required_version=(3, 11)):
+    if sys.version_info < required_version:
+        raise CruInitError(f"Python version must be >= {required_version}!")
+
+
+check_python_version()
diff --git a/tools/cru-py/cru/attr.py b/tools/cru-py/cru/attr.py
new file mode 100644
index 0000000..d07cc55
--- /dev/null
+++ b/tools/cru-py/cru/attr.py
@@ -0,0 +1,125 @@
+from collections.abc import Callable
+from dataclasses import dataclass
+from types import NoneType
+from typing import Any
+from copy import deepcopy
+
+
+@dataclass
+class CruAttr:
+    name: str
+    value: Any
+    description: str
+
+
+@dataclass
+class CruAttrDef:
+    name: str
+    default_description: str
+    allow_types: None | set[type]
+    allow_none: bool
+    default_value: Any
+    transformer: Callable[[Any], Any] | None
+    validator: Callable[[Any], None]
+
+    def __init__(self, name: str, default_description: str, *,
+                 allow_types: list[type] | type | None, allow_none: bool, default_value: Any = None,
+                 transformer: Callable[[Any], Any] | None = None,
+                 validator: Callable[[Any], None] | None = None) -> None:
+        self.name = name
+        self.default_description = default_description
+        self.default_value = default_value
+        #TODO: CONTINUE TOMORROW
+        if allow_types is None:
+            allow_types = []
+        elif isinstance(allow_types, type):
+            allow_types = [allow_types]
+        else:
+            for t in allow_types:
+                if not isinstance(t, type):
+                    raise TypeError(f"Invalid value of python type : {t}")
+        self.allow_types = set(filter(lambda tt: tt is not NoneType, allow_types))
+        self.allow_none = allow_none
+        self.transformer = transformer
+        self.validator = validator
+        self.default_value = self.transform_and_validate(self.default_value)
+        self.default_value = deepcopy(self.default_value)
+
+    def transform(self, value: Any) -> Any:
+        if self.transformer is not None:
+            return self.transformer(value)
+        return value
+
+    def validate(self, value: Any, /, override_allow_none: bool | None = None) -> None:
+        allow_none = override_allow_none if override_allow_none is not None else self.allow_none
+        if value is None and not allow_none:
+            raise TypeError(f"None is not allowed!")
+        if len(self.allow_types) != 0 and type(value) not in self.allow_types:
+            raise TypeError(f"Type of {value} is not allowed!")
+        if self.validator is not None:
+            return self.validator(value)
+        return None
+
+    def transform_and_validate(self, value: Any, /, override_allow_none: bool | None = None) -> Any:
+        value = self.transform(value)
+        self.validate(value, override_allow_none)
+        return value
+
+    def make(self, value: Any, description: None | str = None) -> CruAttr:
+        value = self.transform_and_validate(value)
+        return CruAttr(self.name, value if value is not None else deepcopy(self.default_value),
+                       description if description is not None else self.default_description)
+
+
+class CruAttrDefRegistry:
+
+    def __init__(self) -> None:
+        self._def_list = []
+
+    @property
+    def items(self) -> list[CruAttrDef]:
+        return self._def_list
+
+    def register(self, def_: CruAttrDef):
+        for i in self._def_list:
+            if i.name == def_.name:
+                raise ValueError(f"Attribute {def_.name} already exists!")
+        self._def_list.append(def_)
+
+    def register_with(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None, allow_none: bool,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        def_ = CruAttrDef(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=allow_none, transformer=transformer, validator=validator)
+        self.register(def_)
+        return def_
+
+    def register_required(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=False, transformer=transformer, validator=validator)
+
+    def register_optional(self, name: str, default_description: str, *,
+                      allow_types: list[type] | type | None,
+                      default_value: Any = None,
+                      transformer: Callable[[Any], Any] | None = None,
+                      validator: Callable[[Any], None] | None = None
+                      ) -> CruAttrDef:
+        return self.register_with(name, default_description, default_value=default_value, allow_types=allow_types,
+                          allow_none=True, transformer=transformer, validator=validator)
+
+    def get_item_optional(self, name: str) -> CruAttrDef | None:
+        for i in self._def_list:
+            if i.name == name:
+                return i
+        return None
+
+    def __getitem__(self, item) -> CruAttrDef | None:
+        return self.get_item_optional(item)
diff --git a/tools/cru-py/cru/config.py b/tools/cru-py/cru/config.py
new file mode 100644
index 0000000..b0c83d5
--- /dev/null
+++ b/tools/cru-py/cru/config.py
@@ -0,0 +1,128 @@
+from typing import Any, TypeVar, Generic
+
+from .excp import CruInternalLogicError
+from .value import ValueType, ValueGenerator, ValidationError
+
+T = TypeVar("T")
+
+
+class ConfigItem(Generic[T]):
+    OptionalValueGenerator = ValueGenerator[T, []] | None
+
+    def __init__(self, name: str, description: str, value_type: ValueType[T], value: T | None, default_value: T, *,
+                 value_generator: OptionalValueGenerator = None) -> None:
+        self._name = name
+        self._description = description
+        self._value_type = value_type
+        self._default_value = default_value
+        self._value_generator = value_generator
+        self._value: T | None = value
+
+    @property
+    def name(self) -> str:
+        return self._name
+
+    @property
+    def description(self) -> str:
+        return self._description
+
+    @property
+    def value_type(self) -> ValueType[T]:
+        return self._value_type
+
+    @property
+    def default_value(self) -> T:
+        return self._default_value
+
+    @property
+    def is_default(self) -> bool:
+        return self._value is None
+
+    @property
+    def is_set(self) -> bool:
+        return not self.is_default
+
+    @property
+    def value(self) -> T:
+        return self._value or self._default_value
+
+    def set_value(self, v: T | str, /, allow_convert_from_str=False):
+        if allow_convert_from_str:
+            self._value = self.value_type.check_value(v)
+        else:
+            self._value = self.value_type.check_value_or_try_convert_from_str(v)
+
+    @value.setter
+    def value(self, v: T) -> None:
+        self.set_value(v)
+
+    @property
+    def value_generator(self) -> OptionalValueGenerator:
+        return self._value_generator
+
+    def generate_value(self, allow_interactive=False) -> T | None:
+        if self.value_generator is None: return None
+        if self.value_generator.interactive and not allow_interactive:
+            return None
+        else:
+            v = self.generate_value()
+            try:
+                self.value_type.check_value(v)
+                return v
+            except ValidationError as e:
+                raise CruInternalLogicError("Config value generator returns invalid value.", name=self.name, inner=e)
+
+    def copy(self) -> "ConfigItem":
+        return ConfigItem(self.name, self.description, self.value_type,
+                          self._value.copy() if self._value is not None else None, self._default_value.copy(),
+                          value_generator=self.value_generator)
+
+
+class Configuration:
+    def __init__(self, items: None | list[ConfigItem] = None) -> None:
+        self._items: list[ConfigItem] = items or []
+
+    @property
+    def items(self) -> list[ConfigItem]:
+        return self._items
+
+    @property
+    def item_map(self) -> dict[str, ConfigItem]:
+        return {i.name: i for i in self.items}
+
+    def get_optional_item(self, name: str) -> ConfigItem | None:
+        for i in self.items:
+            if i.name == name:
+                return i
+        return None
+
+    def clear(self) -> None:
+        self._items.clear()
+
+    def has_item(self, name: str) -> bool:
+        return self.get_optional_item(name) is not None
+
+    def add_item(self, item: ConfigItem):
+        i = self.get_optional_item(item.name)
+        if i is not None:
+            raise CruInternalLogicError("Config item of the name already exists.", name=item.name)
+        self.items.append(item)
+        return item
+
+    def set_value(self, name: str, v: Any, /, allow_convert_from_str=False):
+        i = self.get_optional_item(name)
+        if i is None:
+            raise CruInternalLogicError("No config item of the name. Can't set value.", name=name)
+        i.set_value(v, allow_convert_from_str)
+
+    def copy(self) -> "Configuration":
+        return Configuration([i.copy() for i in self.items])
+
+    def __getitem__(self, name: str) -> ConfigItem:
+        i = self.get_optional_item(name)
+        if i is not None:
+            return i
+        raise CruInternalLogicError('No config item of the name.', name=name)
+
+    def __contains__(self, name: str):
+        return self.has_item(name)
diff --git a/tools/cru-py/cru/excp.py b/tools/cru-py/cru/excp.py
new file mode 100644
index 0000000..5a5871b
--- /dev/null
+++ b/tools/cru-py/cru/excp.py
@@ -0,0 +1,137 @@
+from collections.abc import Callable
+from dataclasses import dataclass
+from types import NoneType
+from typing import Any
+
+from cru.attr import CruAttrDefRegistry
+
+CRU_EXCEPTION_ATTR_DEF_REGISTRY = CruAttrDefRegistry()
+
+
+class CruException(Exception):
+    @staticmethod
+    def transform_inner(inner: Exception | list[Exception] | None):
+        if inner is None:
+            return None
+        if isinstance(inner, Exception):
+            return [inner]
+        if isinstance(inner, list):
+            return inner
+
+    @staticmethod
+    def validate_inner(inner: list[Exception]):
+        for i in inner:
+            if not isinstance(i, Exception):
+                raise TypeError(f"Invalid inner exception: {i}")
+
+    MESSAGE_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("message", "Message describing the exception.",
+                                                                allow_types=str, default_value="")
+    INNER_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("inner", "Inner exception.",
+                                                  allow_types=list, default_value=[],
+                                                  transformer=transform_inner, validator=validate_inner)
+    INTERNAL_DEF = CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_required("internal",
+                                                  "True if the exception is caused by wrong internal logic. False if it is caused by user's wrong input.",
+                                                  allow_types=bool, default_value=False)
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_optional("name", "Name of the object that causes the exception.",
+                                                  allow_types=str)
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_optional("value", "Value that causes the exception.",
+                                                  allow_types=[])
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with("path", "Path that causes the exception.",)
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with("type", "Python type related to the exception.")
+
+    def __init__(self, message: str, *args,
+                 inner: Exception | list[Exception] | None = None,
+                 internal: bool = False,
+                 name: str | None = None,
+                 value: Any | None = None,
+                 path: str | None = None,
+                 type_: type | None = None,
+                 init_attrs: dict[str, Any] | None = None,
+                 attrs: dict[str, Any] | None = None, **kwargs) -> None:
+        super().__init__(message, *args)
+
+        self._attrs = {
+            CruException.MESSAGE_KEY: message,
+            CruException.INTERNAL_KEY: internal,
+            CruException.INNER_KEY: inner,
+            CruException.NAME_KEY: name,
+            CruException.VALUE_KEY: value,
+            CruException.PATH_KEY: path,
+            CruException.TYPE_KEY: type_,
+        }
+        if init_attrs is not None:
+            self._attrs.update(init_attrs)
+        if attrs is not None:
+            self._attrs.update(attrs)
+        self._attrs.update(kwargs)
+
+    @property
+    def message(self) -> str:
+        return self[CruException.MESSAGE_KEY]
+
+    @property
+    def internal(self) -> bool:
+        return self[CruException.INTERNAL_KEY]
+
+    @property
+    def inner(self) -> list[Exception]:
+        return self[CruException.INNER_KEY]
+
+    @property
+    def name(self) -> str | None:
+        return self[CruException.NAME_KEY]
+
+    @property
+    def value(self) -> Any | None:
+        return self[CruException.VALUE_KEY]
+
+    @property
+    def path(self) -> str | None:
+        return self[CruException.PATH_KEY]
+
+    @property
+    def type(self) -> type | None:
+        return self[CruException.TYPE_KEY]
+
+    def _get_attr_list_recursive(self, name: str, depth: int, max_depth: int, l: list[Any]):
+        if 0 < max_depth < depth + 1:
+            return
+        a = self._attrs.get(name, None)
+        if a is not None:
+            l.append(a)
+        for i in self.inner:
+            if isinstance(i, CruException):
+                i._get_attr_list_recursive(name, depth + 1, max_depth, l)
+
+    def get_attr_list_recursive(self, name: str, /, max_depth: int = -1) -> list[Any]:
+        l = []
+        self._get_attr_list_recursive(name, 0, max_depth, l)
+        return l
+
+    def get_optional_attr(self, name: str, max_depth: int = -1) -> Any | None:
+        l = self.get_attr_list_recursive(name, max_depth)
+        return l[0] if len(l) > 0 else None
+
+    def __getitem__(self, name: str) -> Any | None:
+        return self.get_optional_attr(name)
+
+
+class CruInternalLogicError(CruException):
+    def __init__(self, message: str, *args, **kwargs) -> None:
+        super().__init__(message, *args, internal=True, **kwargs)
+
+
+class UserFriendlyException(CruException):
+    USER_MESSAGE_KEY = "user_message"
+
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register(
+        CruExceptionAttrDef(USER_MESSAGE_KEY, "Message describing the exception, but with user-friendly language."))
+
+    def __init__(self, message: str, user_message: str | None = None, *args, **kwargs) -> None:
+        if user_message is None:
+            user_message = message
+        super().__init__(message, *args, init_attrs={UserFriendlyException.USER_MESSAGE_KEY: user_message}, **kwargs)
+
+    @property
+    def user_message(self) -> str:
+        return self[UserFriendlyException.USER_MESSAGE_KEY]
diff --git a/tools/cru-py/cru/parsing.py b/tools/cru-py/cru/parsing.py
new file mode 100644
index 0000000..be7bbf4
--- /dev/null
+++ b/tools/cru-py/cru/parsing.py
@@ -0,0 +1,70 @@
+from abc import ABCMeta, abstractmethod
+from typing import TypeVar, Generic, NoReturn, Callable
+
+from cru.excp import CruException, CRU_EXCEPTION_ATTR_DEF_REGISTRY
+
+R = TypeVar("R")
+
+
+class ParseException(CruException):
+    LINE_NUMBER_KEY = "line_number"
+
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with(LINE_NUMBER_KEY, "Line number of the error.")
+
+
+class Parser(Generic[R], metaclass=ABCMeta):
+    def __init__(self, name: str) -> None:
+        self._name = name
+
+    @property
+    def name(self) -> str:
+        return self._name
+
+    @abstractmethod
+    def parse(self, s: str) -> R:
+        raise NotImplementedError()
+
+    def raise_parse_exception(self, s: str, line_number: int | None = None) -> NoReturn:
+        a = f" at line {line_number}" if line_number is not None else ""
+        raise ParseException(f"Parser {self.name} failed{a}, {s}")
+
+
+class SimpleLineConfigParser(Parser[list[tuple[str, str]]]):
+    def __init__(self) -> None:
+        super().__init__(type(self).__name__)
+
+    def _parse(self, s: str, f: Callable[[str, str], None]) -> None:
+        for ln, line in enumerate(s.splitlines()):
+            line_number = ln + 1
+            # check if it's a comment
+            if line.strip().startswith("#"):
+                continue
+            # check if there is a '='
+            if line.find("=") == -1:
+                self.raise_parse_exception(f"There is even no '='!", line_number)
+            # split at first '='
+            key, value = line.split("=", 1)
+            key = key.strip()
+            value = value.strip()
+            f(key, value)
+
+    def parse(self, s: str) -> list[tuple[str, str]]:
+        items = []
+        self._parse(s, lambda key, value: items.append((key, value)))
+        return items
+
+    def parse_to_dict(self, s: str, /, allow_override: bool = False) -> tuple[dict[str, str], list[tuple[str, str]]]:
+        d = {}
+        duplicate = []
+
+        def add(key: str, value: str) -> None:
+            if key in d:
+                if allow_override:
+                    duplicate.append((key, d[key]))
+                    d[key] = value
+                else:
+                    self.raise_parse_exception(f"Key '{key}' already exists!", None)
+            d[key] = value
+
+        self._parse(s, add)
+        return d, duplicate
diff --git a/tools/cru-py/cru/paths.py b/tools/cru-py/cru/paths.py
new file mode 100644
index 0000000..df5042b
--- /dev/null
+++ b/tools/cru-py/cru/paths.py
@@ -0,0 +1,63 @@
+from pathlib import Path
+import os
+
+from .excp import CruException
+
+
+class ApplicationPathError(CruException):
+    def __init__(self, message: str, p: str | Path, *args, **kwargs):
+        super().__init__(message, *args, path=str(p), **kwargs)
+
+
+def check_parents_dir(p: str | Path, /, must_exist: bool = False) -> bool:
+    p = Path(p) if isinstance(p, str) else p
+    for p in reversed(p.parents):
+        if not p.exists() and not must_exist:
+            return False
+        if not p.is_dir():
+            raise ApplicationPathError("Parents path should be a dir.", p)
+    return True
+
+
+class ApplicationPath:
+    def __init__(self, p: str | Path, is_dir: bool) -> None:
+        self._path = Path(p) if isinstance(p, str) else p
+        self._is_dir = is_dir
+
+    @property
+    def path(self) -> Path:
+        return self._path
+
+    @property
+    def is_dir(self) -> bool:
+        return self._is_dir
+
+    def check_parents(self, must_exist: bool = False) -> bool:
+        return check_parents_dir(self._path.parent, must_exist)
+
+    def check_self(self, must_exist: bool = False) -> bool:
+        if not self.check_parents(must_exist):
+            return False
+        if not self.path.exists():
+            if not must_exist: return False
+            raise ApplicationPathError("Mot exist.", self.path)
+        if self.is_dir:
+            if not self.path.is_dir():
+                raise ApplicationPathError("Should be a directory, but not.", self.path)
+            else:
+                return False
+        else:
+            if not self.path.is_file():
+                raise ApplicationPathError("Should be a file, but not.", self.path)
+            else:
+                return False
+
+    def ensure(self, create_file: bool = False) -> None:
+        e = self.check_self(False)
+        if not e:
+            os.makedirs(self.path.parent, exist_ok=True)
+            if self.is_dir:
+                os.mkdir(self.path)
+            elif create_file:
+                with open(self.path, "w") as f:
+                    f.write("")
diff --git a/tools/cru-py/cru/service/__init__.py b/tools/cru-py/cru/service/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tools/cru-py/cru/service/__init__.py
diff --git a/tools/cru-py/cru/service/docker.py b/tools/cru-py/cru/service/docker.py
new file mode 100644
index 0000000..42d4a35
--- /dev/null
+++ b/tools/cru-py/cru/service/docker.py
@@ -0,0 +1,15 @@
+import shutil
+
+
+class DockerController:
+    DOCKER_BIN_NAME = "docker"
+
+    def __init__(self, docker_bin: None | str = None) -> None:
+        self._docker_bin = docker_bin
+
+    @property
+    def docker_bin(self) -> str:
+        if self._docker_bin is None:
+            self._docker_bin = shutil.which(self.DOCKER_BIN_NAME)
+        return self._docker_bin
+
diff --git a/tools/cru-py/cru/service/nginx.py b/tools/cru-py/cru/service/nginx.py
new file mode 100644
index 0000000..9298623
--- /dev/null
+++ b/tools/cru-py/cru/service/nginx.py
@@ -0,0 +1,377 @@
+from typing import Literal, Any, cast, ClassVar
+import os
+from os.path import join, basename, dirname
+import subprocess
+import re
+import json
+import jsonschema
+
+from crupest.template2 import Template2
+from crupest.tui import Paths, UserFriendlyException, create_dir_if_not_exists, console, Confirm, ensure_dir
+from crupest.ui_base import file_name_style
+
+
+def restart_nginx(force=False) -> bool:
+    if not force:
+        p = subprocess.run(['docker', "container", "ls",
+                            "-f", "name=nginx", "-q"], capture_output=True)
+        container: str = p.stdout.decode("utf-8")
+        if len(container.strip()) == 0:
+            return False
+    subprocess.run(['docker', 'restart', 'nginx'])
+    return True
+
+
+_server_schema_filename = "server.schema.json"
+
+with open(join(Paths.nginx2_template_dir, _server_schema_filename)) as f:
+    server_json_schema = json.load(f)
+
+
+_domain_template_filename = "domain.conf.template"
+
+NginxSourceFileType = Literal["global", "domain", "http", "https"]
+
+
+class NginxSourceFile:
+    def __init__(self, path: str) -> None:
+        """
+        path: relative to nginx2_template_dir
+        """
+        self._path = path
+        is_template = path.endswith(".template")
+        self._is_template = is_template
+        filename = basename(path)
+        self.name = filename[:-len(".template")] if is_template else filename
+        if is_template:
+            self._template = Template2.from_file(
+                join(Paths.nginx2_template_dir, path))
+        else:
+            with open(join(Paths.nginx2_template_dir, path)) as f:
+                self._content = f.read()
+
+        self._scope: NginxSourceFileType = self._calc_scope()
+
+    @property
+    def is_template(self) -> bool:
+        return self._is_template
+
+    @property
+    def content(self) -> str:
+        if self._is_template:
+            raise Exception(f"{self._path} is a template file")
+        return self._content
+
+    @property
+    def template(self) -> Template2:
+        if not self._is_template:
+            raise Exception(f"{self._path} is not a template file")
+        return cast(Template2, self._template)
+
+    @property
+    def global_target_filename(self) -> str:
+        if self.scope != "global":
+            raise Exception(f"{self._path} is not a global file")
+        if self.is_template:
+            return basename(self._path)[:-len(".template")]
+        else:
+            return basename(self._path)
+
+    def _calc_scope(self) -> NginxSourceFileType:
+        f = basename(self._path)
+        d = basename(dirname(self._path))
+        if f == _domain_template_filename:
+            return "domain"
+        elif d in ["global", "http", "https"]:
+            return cast(Literal["global", "http", "https"], d)
+        else:
+            raise Exception(f"Unknown scope for {self._path}")
+
+    @property
+    def scope(self) -> NginxSourceFileType:
+        return self._scope
+
+
+_domain_template_source = NginxSourceFile(_domain_template_filename)
+
+_client_max_body_size_source = NginxSourceFile(
+    "global/client-max-body-size.conf")
+_forbid_unknown_domain_source = NginxSourceFile(
+    "global/forbid-unknown-domain.conf")
+_ssl_template_source = NginxSourceFile("global/ssl.conf.template")
+_websocket_source = NginxSourceFile("global/websocket.conf")
+
+_http_444_source = NginxSourceFile("http/444.segment")
+_http_redirect_to_https_source = NginxSourceFile(
+    "http/redirect-to-https.segment")
+
+_https_redirect_template_source = NginxSourceFile(
+    "https/redirect.segment.template")
+_https_reverse_proxy_template_source = NginxSourceFile(
+    "https/reverse-proxy.segment.template")
+_https_static_file_template_source = NginxSourceFile(
+    "https/static-file.segment.template")
+_https_static_file_no_strip_prefix_template_source = NginxSourceFile(
+    "https/static-file.no-strip-prefix.segment.template")
+
+
+class NginxService:
+    def __init__(self, type: str, path: str) -> None:
+        self.type = type
+        self.path = path
+        self._check_path(path)
+
+    @staticmethod
+    def _check_path(path: str) -> None:
+        assert isinstance(path, str)
+        if path == "" or path == "/":
+            return
+        if not path.startswith("/"):
+            raise UserFriendlyException("Service path should start with '/'.")
+        if path.endswith("/"):
+            raise UserFriendlyException(
+                "Service path should not end with '/'.")
+
+    def generate_https_segment(self) -> str:
+        raise NotImplementedError()
+
+
+class NginxRedirectService(NginxService):
+    def __init__(self, path: str, redirect_url: str, redirect_code: int = 307) -> None:
+        if redirect_url.endswith("/"):
+            raise UserFriendlyException(
+                "Redirect URL should not end with '/'.")
+
+        super().__init__("redirect", path)
+
+        self.redirect_url = redirect_url
+        self.redirect_code = redirect_code
+
+    def generate_https_segment(self) -> str:
+        vars = {
+            "PATH": self.path,
+            "REDIRECT_CODE": self.redirect_code,
+            "REDIRECT_URL": self.redirect_url
+        }
+        return _https_redirect_template_source.template.render(vars)
+
+    @staticmethod
+    def from_json(json: dict[str, Any]) -> "NginxRedirectService":
+        path = json["path"]
+        redirect_url = json["to"]
+        redirect_code = json.get("code", 307)
+        assert isinstance(path, str)
+        assert isinstance(redirect_url, str)
+        assert isinstance(redirect_code, int)
+        return NginxRedirectService(path, redirect_url, redirect_code)
+
+
+class NginxReverseProxyService(NginxService):
+
+    _upstream_regex: ClassVar[re.Pattern[str]] = re.compile(
+        r"^[-_0-9a-zA-Z]+:[0-9]+$")
+
+    def __init__(self, path: str, upstream: str) -> None:
+        if not self._upstream_regex.match(upstream):
+            raise UserFriendlyException(
+                f"Invalid upstream format: {upstream}.")
+
+        super().__init__("reverse-proxy", path)
+
+        self.upstream = upstream
+
+    def generate_https_segment(self) -> str:
+        vars = {
+            "PATH": self.path,
+            "UPSTREAM": self.upstream
+        }
+        return _https_reverse_proxy_template_source.template.render(vars)
+
+    @staticmethod
+    def from_json(json: dict[str, Any]) -> "NginxReverseProxyService":
+        path = json["path"]
+        upstream = json["upstream"]
+        assert isinstance(path, str)
+        assert isinstance(upstream, str)
+        return NginxReverseProxyService(path, upstream)
+
+
+class NginxStaticFileService(NginxService):
+    def __init__(self, path: str, root: str, no_strip_prefix: bool = False) -> None:
+        super().__init__("static-file", path)
+
+        self.root = root
+        self.no_strip_prefix = no_strip_prefix
+
+    def generate_https_segment(self) -> str:
+        vars = {
+            "PATH": self.path,
+            "ROOT": self.root,
+        }
+        if self.no_strip_prefix:
+            return _https_static_file_no_strip_prefix_template_source.template.render(vars)
+        else:
+            return _https_static_file_template_source.template.render(vars)
+
+    @staticmethod
+    def from_json(json: dict[str, Any]) -> "NginxStaticFileService":
+        path = json["path"]
+        root = json["root"]
+        no_strip_prefix = json.get("no_strip_prefix", False)
+        assert isinstance(path, str)
+        assert isinstance(root, str)
+        assert isinstance(no_strip_prefix, bool)
+        return NginxStaticFileService(path, root, no_strip_prefix)
+
+
+def nginx_service_from_json(json: dict[str, Any]) -> NginxService:
+    type = json["type"]
+    if type == "redirect":
+        return NginxRedirectService.from_json(json)
+    elif type == "reverse-proxy":
+        return NginxReverseProxyService.from_json(json)
+    elif type == "static-file":
+        return NginxStaticFileService.from_json(json)
+    else:
+        raise UserFriendlyException(f"Invalid crupest type: {type}.")
+
+
+def _prepend_indent(text: str, indent: str = " " * 4) -> str:
+    lines = text.split("\n")
+    for i in range(len(lines)):
+        if lines[i] != "":
+            lines[i] = indent + lines[i]
+    return "\n".join(lines)
+
+
+class NginxDomain:
+    def __init__(self, domain: str, services: list[NginxService] = []) -> None:
+        self.domain = domain
+        self.services = services
+
+    def add_service(self, service: NginxService) -> None:
+        self.services.append(service)
+
+    def generate_http_segment(self) -> str:
+        if len(self.services) == 0:
+            return _http_444_source.content
+        else:
+            return _http_redirect_to_https_source.content
+
+    def generate_https_segment(self) -> str:
+        return "\n\n".join([s.generate_https_segment() for s in self.services])
+
+    def generate_config(self) -> str:
+        vars = {
+            "DOMAIN": self.domain,
+            "HTTP_SEGMENT": _prepend_indent(self.generate_http_segment()),
+            "HTTPS_SEGMENT": _prepend_indent(self.generate_https_segment()),
+        }
+        return _domain_template_source.template.render(vars)
+
+    def generate_config_file(self, path: str) -> None:
+        with open(path, "w") as f:
+            f.write(self.generate_config())
+
+    @staticmethod
+    def from_json(root_domain: str, json: dict[str, Any]) -> "NginxDomain":
+        name = json["name"]
+        assert isinstance(name, str)
+        if name == "@" or name == "":
+            domain = root_domain
+        else:
+            domain = f"{name}.{root_domain}"
+        assert isinstance(json["services"], list)
+        services = [nginx_service_from_json(s) for s in json["services"]]
+        return NginxDomain(domain, services)
+
+
+def check_nginx_config_schema(json: Any) -> None:
+    jsonschema.validate(json, server_json_schema)
+
+
+class NginxServer:
+    def __init__(self, root_domain: str) -> None:
+        self.root_domain = root_domain
+        self.domains: list[NginxDomain] = []
+
+    def add_sub_domain(self, sub_domain: str, services: list[NginxService]) -> None:
+        if sub_domain == "" or sub_domain == "@":
+            domain = self.root_domain
+        else:
+            domain = f"{sub_domain}.{self.root_domain}"
+        self.domains.append(NginxDomain(domain, services))
+
+    def generate_ssl(self) -> str:
+        return _ssl_template_source.template.render({
+            "ROOT_DOMAIN": self.root_domain
+        })
+
+    def generate_global_files(self, d: str) -> None:
+        for source in [_client_max_body_size_source, _forbid_unknown_domain_source, _websocket_source]:
+            with open(join(d, source.name), "w") as f:
+                f.write(source.content)
+        with open(join(d, _ssl_template_source.name), "w") as f:
+            f.write(self.generate_ssl())
+
+    def generate_domain_files(self, d: str) -> None:
+        for domain in self.domains:
+            domain.generate_config_file(join(d, f"{domain.domain}.conf"))
+
+    def generate_config(self, d: str) -> None:
+        create_dir_if_not_exists(d)
+        self.generate_global_files(d)
+
+    def get_allowed_files(self) -> list[str]:
+        files = []
+        for source in [_client_max_body_size_source, _forbid_unknown_domain_source, _ssl_template_source, _websocket_source]:
+            files.append(source.name)
+        for domain in self.domains:
+            files.append(f"{domain.domain}.conf")
+        return files
+
+    def check_bad_files(self, d: str) -> list[str]:
+        allowed_files = self.get_allowed_files()
+        bad_files = []
+        if not ensure_dir(d, must_exist=False):
+            return []
+        for path in os.listdir(d):
+            if path not in allowed_files:
+                bad_files.append(path)
+        return bad_files
+
+    @staticmethod
+    def from_json(root_domain: str, json: dict[str, Any]) -> "NginxServer":
+        check_nginx_config_schema(json)
+        server = NginxServer(root_domain)
+        sub_domains = json["domains"]
+        assert isinstance(sub_domains, list)
+        server.domains = [NginxDomain.from_json(
+            root_domain, d) for d in sub_domains]
+        return server
+
+    @staticmethod
+    def from_json_str(root_domain: str, json_str: str) -> "NginxServer":
+        return NginxServer.from_json(root_domain, json.loads(json_str))
+
+    def go(self):
+        bad_files = self.check_bad_files(Paths.nginx_generated_dir)
+        if len(bad_files) > 0:
+            console.print(
+                "WARNING: It seems there are some bad conf files in the nginx config directory:", style="yellow")
+            for bad_file in bad_files:
+                console.print(bad_file, style=file_name_style)
+            to_delete = Confirm.ask(
+                "They will affect nginx in a [red]bad[/] way. Do you want to delete them?", default=True, console=console)
+            if to_delete:
+                for file in bad_files:
+                    os.remove(join(Paths.nginx_generated_dir, file))
+        create_dir_if_not_exists(Paths.generated_dir)
+        if not ensure_dir(Paths.nginx_generated_dir, must_exist=False):
+            os.mkdir(Paths.nginx_generated_dir)
+            console.print(
+                f"Nginx config directory created at [magenta]{Paths.nginx_generated_dir}[/]", style="green")
+        self.generate_config(Paths.nginx_generated_dir)
+        console.print("Nginx config generated.", style="green")
+        if restart_nginx():
+            console.print('Nginx restarted.', style="green")
diff --git a/tools/cru-py/cru/system.py b/tools/cru-py/cru/system.py
new file mode 100644
index 0000000..2e05cd1
--- /dev/null
+++ b/tools/cru-py/cru/system.py
@@ -0,0 +1,22 @@
+import re
+import os.path
+
+
+def check_debian_derivative_version(name: str) -> None | str:
+    if not os.path.isfile("/etc/os-release"):
+        return None
+    with open("/etc/os-release", "r") as f:
+        content = f.read()
+        if not f"ID={name}" in content:
+            return None
+        m = re.search(r'VERSION_ID="(.+)"', content)
+        if m is None: return None
+        return m.group(1)
+
+
+def check_ubuntu_version() -> None | str:
+    return check_debian_derivative_version("ubuntu")
+
+
+def check_debian_version() -> None | str:
+    return check_debian_derivative_version("debian")
diff --git a/tools/cru-py/cru/value.py b/tools/cru-py/cru/value.py
new file mode 100644
index 0000000..cddbde9
--- /dev/null
+++ b/tools/cru-py/cru/value.py
@@ -0,0 +1,309 @@
+import random
+import secrets
+import string
+import uuid
+from abc import abstractmethod, ABCMeta
+from collections.abc import Mapping, Callable
+from typing import Any, ClassVar, Literal, TypeVar, Generic, ParamSpec
+
+from .excp import CruInternalLogicError, CruException, CRU_EXCEPTION_ATTR_DEF_REGISTRY
+
+
+def _str_case_in(s: str, case: bool, l: list[str]) -> bool:
+    if case:
+        return s in l
+    else:
+        return s.lower() in [s.lower() for s in l]
+
+
+_ValueTypeForward = type["ValueType"]
+
+T = TypeVar("T")
+
+
+class _ValueErrorMixin:
+    VALUE_TYPE_KEY = "value_type"
+
+    CRU_EXCEPTION_ATTR_DEF_REGISTRY.register_with(
+        VALUE_TYPE_KEY,
+        "The type of the value that causes the exception."
+    )
+
+
+class ValidationError(CruException, _ValueErrorMixin):
+    def __init__(self, message: str, value: Any, value_type: _ValueTypeForward[T] | None, *args, **kwargs):
+        super().__init__(message, *args, value=value, type_=value_type.type, init_attrs={
+            ValidationError.VALUE_TYPE_KEY: value_type,
+        }, **kwargs)
+
+    @property
+    def value_type(self) -> _ValueTypeForward[T] | None:
+        return self[ValidationError.VALUE_TYPE_KEY]
+
+
+class ValueStringConvertionError(CruException, _ValueErrorMixin):
+    def __init__(self, message: str, value: Any, value_type: _ValueTypeForward[T] | None, *args,
+                 **kwargs):
+        super().__init__(message, *args, value=value, type_=value_type.type, init_attrs={
+            ValueStringConvertionError.VALUE_TYPE_KEY: value_type,
+        }, **kwargs)
+
+    @property
+    def value_type(self) -> _ValueTypeForward[T] | None:
+        return self[ValueStringConvertionError.VALUE_TYPE_KEY]
+
+
+class ValueType(Generic[T], metaclass=ABCMeta):
+    @staticmethod
+    def case_sensitive_to_str(case_sensitive: bool) -> str:
+        return f"case-{'' if case_sensitive else 'in'}sensitive"
+
+    def __init__(self, name: str) -> None:
+        self._name = name
+        self._type = type("T")
+
+    @property
+    def name(self) -> str:
+        return self._name
+
+    @property
+    def type(self) -> type:
+        return self._type
+
+    def is_instance_of_value_type(self, value: Any) -> bool:
+        return isinstance(value, self.type)
+
+    def _do_check_value(self, value: Any) -> tuple[True, T] | tuple[False, None | str]:
+        return True, value
+
+    def check_value(self, value: Any) -> T:
+        if not isinstance(value, self.type):
+            raise ValidationError("Value type is wrong.", value, self)
+        ok, v_or_err = self._do_check_value(value)
+        if ok:
+            return v_or_err
+        else:
+            raise ValidationError(v_or_err or "Value is not valid.", value, self)
+
+    @abstractmethod
+    def _do_check_str_format(self, s: str) -> bool | tuple[bool, str]:
+        """
+        Return None for no error. Otherwise, return error message.
+        """
+        raise NotImplementedError()
+
+    def check_str_format(self, s: str) -> None:
+        ok, err = self._do_check_str_format(s)
+        if ok is None: raise CruInternalLogicError("_do_check_str_format should not return None.")
+        if ok: return
+        if err is None:
+            err = "Invalid value str format."
+        raise ValueStringConvertionError(err, s, value_type=self)
+
+    @abstractmethod
+    def _do_convert_value_to_str(self, value: T) -> str:
+        raise NotImplementedError()
+
+    def convert_value_to_str(self, value: T) -> str:
+        self.check_value(value)
+        return self._do_convert_value_to_str(value)
+
+    @abstractmethod
+    def _do_convert_str_to_value(self, s: str) -> T:
+        raise NotImplementedError()
+
+    def convert_str_to_value(self, s: str) -> T:
+        self.check_str_format(s)
+        return self._do_convert_str_to_value(s)
+
+    def check_value_or_try_convert_from_str(self, value_or_str: Any) -> T:
+        try:
+            return self.check_value(value_or_str)
+        except ValidationError as e:
+            if isinstance(value_or_str, str):
+                return self.convert_str_to_value(value_or_str)
+            else:
+                raise ValidationError("Value is not valid and is not a str.", value_or_str, self,
+                                      inner=e)
+
+
+class TextValueType(ValueType[str]):
+    def __init__(self) -> None:
+        super().__init__("text")
+
+    def _do_check_str_format(self, s):
+        return True
+
+    def _do_convert_value_to_str(self, value):
+        return value
+
+    def _do_convert_str_to_value(self, s):
+        return s
+
+
+class IntegerValueType(ValueType[int]):
+
+    def __init__(self) -> None:
+        super().__init__("integer")
+
+    def _do_check_str_format(self, s):
+        try:
+            int(s)
+            return True
+        except ValueError:
+            return False
+
+    def _do_convert_value_to_str(self, value):
+        return str(value)
+
+    def _do_convert_str_to_value(self, s):
+        return int(s)
+
+
+class FloatValueType(ValueType[float]):
+    def __init__(self) -> None:
+        super().__init__("float")
+
+    def _do_check_str_format(self, s):
+        try:
+            float(s)
+            return True
+        except ValueError:
+            return False
+
+    def _do_convert_value_to_str(self, value):
+        return str(value)
+
+    def _do_convert_str_to_value(self, s):
+        return float(s)
+
+
+class BooleanValueType(ValueType[bool]):
+    DEFAULT_TRUE_LIST: ClassVar[list[str]] = ["true", "yes", "y", "on", "1"]
+    DEFAULT_FALSE_LIST: ClassVar[list[str]] = ["false", "no", "n", "off", "0"]
+
+    def __init__(self, *, case_sensitive=False, true_list: None | list[str] = None,
+                 false_list: None | list[str] = None) -> None:
+        super().__init__("boolean")
+        self._case_sensitive = case_sensitive
+        self._valid_true_strs: list[str] = true_list or BooleanValueType.DEFAULT_TRUE_LIST
+        self._valid_false_strs: list[str] = false_list or BooleanValueType.DEFAULT_FALSE_LIST
+
+    @property
+    def case_sensitive(self) -> bool:
+        return self._case_sensitive
+
+    @property
+    def valid_true_strs(self) -> list[str]:
+        return self._valid_true_strs
+
+    @property
+    def valid_false_strs(self) -> list[str]:
+        return self._valid_false_strs
+
+    @property
+    def valid_boolean_strs(self) -> list[str]:
+        return self._valid_true_strs + self._valid_false_strs
+
+    def _do_check_str_format(self, s):
+        if _str_case_in(s, self.case_sensitive, self.valid_boolean_strs): return True
+        return False, f"Not a valid boolean string ({ValueType.case_sensitive_to_str(self.case_sensitive)}). Valid string of true: {' '.join(self._valid_true_strs)}. Valid string of false: {' '.join(self._valid_false_strs)}. All is case insensitive."
+
+    def _do_convert_value_to_str(self, value):
+        return "True" if value else "False"
+
+    def _do_convert_str_to_value(self, s):
+        return _str_case_in(s, self.case_sensitive, self._valid_true_strs)
+
+
+class EnumValueType(ValueType[str]):
+    def __init__(self, valid_values: list[str], /, case_sensitive=False) -> None:
+        s = ' | '.join([f'"{v}"' for v in valid_values])
+        self._valid_value_str = f'[ {s} ]'
+        super().__init__(f"enum{self._valid_value_str}")
+        self._case_sensitive = case_sensitive
+        self._valid_values = valid_values
+
+    @property
+    def case_sensitive(self) -> bool:
+        return self._case_sensitive
+
+    @property
+    def valid_values(self) -> list[str]:
+        return self._valid_values
+
+    def _do_check_value(self, value):
+        ok, err = self._do_check_str_format(value)
+        return ok, (value if ok else err)
+
+    def _do_check_str_format(self, s):
+        if _str_case_in(s, self.case_sensitive, self.valid_values): return True
+        return False, f"Value is not in valid values ({ValueType.case_sensitive_to_str(self.case_sensitive)}): {self._valid_value_str}"
+
+    def _do_convert_value_to_str(self, value):
+        return value
+
+    def _do_convert_str_to_value(self, s):
+        return s
+
+
+TEXT_VALUE_TYPE = TextValueType()
+INTEGER_VALUE_TYPE = IntegerValueType()
+BOOLEAN_VALUE_TYPE = BooleanValueType()
+
+P = ParamSpec('P')
+
+
+class ValueGenerator(Generic[T, P]):
+    INTERACTIVE_KEY: ClassVar[Literal["interactive"]] = "interactive"
+
+    def __init__(self, f: Callable[P, T], /, attributes: None | Mapping[str, Any] = None) -> None:
+        self._f = f
+        self._attributes = attributes or {}
+
+    @property
+    def f(self) -> Callable[P, T]:
+        return self._f
+
+    @property
+    def attributes(self) -> Mapping[str, Any]:
+        return self._attributes
+
+    def generate(self, *args, **kwargs) -> T:
+        return self._f(*args, **kwargs)
+
+    def __call__(self, *args, **kwargs):
+        return self._f(*args, **kwargs)
+
+    @property
+    def interactive(self) -> bool:
+        return self._attributes.get(ValueGenerator.INTERACTIVE_KEY, False)
+
+    @staticmethod
+    def create_interactive(f: Callable[P, T], interactive: bool = True, /,
+                           attributes: None | Mapping[str, Any] = None) -> "ValueGenerator[T, P]":
+        return ValueGenerator(f, dict({ValueGenerator.INTERACTIVE_KEY: interactive}, **(attributes or {})))
+
+
+class UuidValueGenerator(ValueGenerator[str, []]):
+    def __init__(self) -> None:
+        super().__init__(lambda: str(uuid.uuid4()))
+
+
+class RandomStringValueGenerator(ValueGenerator[str, []]):
+    @staticmethod
+    def _create_generate_ramdom_func(length: int, secure: bool) -> Callable[str, []]:
+        random_choice = secrets.choice if secure else random.choice
+
+        def generate_random_string():
+            characters = string.ascii_letters + string.digits
+            random_string = ''.join(random_choice(characters) for _ in range(length))
+            return random_string
+
+        return generate_random_string
+
+    def __init__(self, length: int, secure: bool) -> None:
+        super().__init__(RandomStringValueGenerator._create_generate_ramdom_func(length, secure))
+
+
+UUID_VALUE_GENERATOR = UuidValueGenerator()