move all environment variables to the same place (#4192)

* move all environment variables to the same place

* reorder things around

* move more variables to environment

* remove cyclical imports

* forgot default value for field

* for some reason type hints aren't being interpreted

* put the field type *before* not after

* make it get

* move a bit more

* add more fields

* move reflex dir

* add return

* put things somewhere else

* add custom error

reflex/app.py

@@ -64,7 +64,7 @@
 )
 from reflex.components.core.upload import Upload, get_upload_dir
 from reflex.components.radix import themes
-from reflex.config import get_config
+from reflex.config import environment, get_config
 from reflex.event import Event, EventHandler, EventSpec, window_alert
 from reflex.model import Model, get_db_status
 from reflex.page import (
@@ -957,15 +957,16 @@ def get_compilation_time() -> str:
         executor = None
         if (
             platform.system() in ("Linux", "Darwin")
-            and os.environ.get("REFLEX_COMPILE_PROCESSES") is not None
+            and (number_of_processes := environment.REFLEX_COMPILE_PROCESSES)
+            is not None
         ):
             executor = concurrent.futures.ProcessPoolExecutor(
-                max_workers=int(os.environ.get("REFLEX_COMPILE_PROCESSES", 0)) or None,
+                max_workers=number_of_processes,
                 mp_context=multiprocessing.get_context("fork"),
             )
         else:
             executor = concurrent.futures.ThreadPoolExecutor(
-                max_workers=int(os.environ.get("REFLEX_COMPILE_THREADS", 0)) or None,
+                max_workers=environment.REFLEX_COMPILE_THREADS
             )
 
         with executor:

reflex/compiler/compiler.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import os
 from datetime import datetime
 from pathlib import Path
 from typing import Dict, Iterable, Optional, Type, Union
@@ -16,7 +15,7 @@
     CustomComponent,
     StatefulComponent,
 )
-from reflex.config import get_config
+from reflex.config import environment, get_config
 from reflex.state import BaseState
 from reflex.style import SYSTEM_COLOR_MODE
 from reflex.utils.exec import is_prod_mode
@@ -527,7 +526,7 @@ def remove_tailwind_from_postcss() -> tuple[str, str]:
 
 def purge_web_pages_dir():
     """Empty out .web/pages directory."""
-    if not is_prod_mode() and os.environ.get("REFLEX_PERSIST_WEB_DIR"):
+    if not is_prod_mode() and environment.REFLEX_PERSIST_WEB_DIR:
         # Skip purging the web directory in dev mode if REFLEX_PERSIST_WEB_DIR is set.
         return
 

reflex/components/core/upload.py

@@ -2,13 +2,13 @@
 
 from __future__ import annotations
 
-import os
 from pathlib import Path
 from typing import Any, Callable, ClassVar, Dict, List, Optional, Tuple
 
 from reflex.components.component import Component, ComponentNamespace, MemoizationLeaf
 from reflex.components.el.elements.forms import Input
 from reflex.components.radix.themes.layout.box import Box
+from reflex.config import environment
 from reflex.constants import Dirs
 from reflex.event import (
     CallableEventSpec,
@@ -125,9 +125,7 @@ def get_upload_dir() -> Path:
     """
     Upload.is_used = True
 
-    uploaded_files_dir = Path(
-        os.environ.get("REFLEX_UPLOADED_FILES_DIR", "./uploaded_files")
-    )
+    uploaded_files_dir = environment.REFLEX_UPLOADED_FILES_DIR
     uploaded_files_dir.mkdir(parents=True, exist_ok=True)
     return uploaded_files_dir
 

reflex/config.py

@@ -2,14 +2,18 @@
 
 from __future__ import annotations
 
+import dataclasses
 import importlib
 import os
 import sys
 import urllib.parse
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Set, Union
 
-from reflex.utils.exceptions import ConfigError
+from typing_extensions import get_type_hints
+
+from reflex.utils.exceptions import ConfigError, EnvironmentVarValueError
+from reflex.utils.types import value_inside_optional
 
 try:
     import pydantic.v1 as pydantic
@@ -131,6 +135,198 @@ def get_url(self) -> str:
         return f"{self.engine}://{path}/{self.database}"
 
 
+def get_default_value_for_field(field: dataclasses.Field) -> Any:
+    """Get the default value for a field.
+
+    Args:
+        field: The field.
+
+    Returns:
+        The default value.
+
+    Raises:
+        ValueError: If no default value is found.
+    """
+    if field.default != dataclasses.MISSING:
+        return field.default
+    elif field.default_factory != dataclasses.MISSING:
+        return field.default_factory()
+    else:
+        raise ValueError(
+            f"Missing value for environment variable {field.name} and no default value found"
+        )
+
+
+def interpret_boolean_env(value: str) -> bool:
+    """Interpret a boolean environment variable value.
+
+    Args:
+        value: The environment variable value.
+
+    Returns:
+        The interpreted value.
+
+    Raises:
+        EnvironmentVarValueError: If the value is invalid.
+    """
+    true_values = ["true", "1", "yes", "y"]
+    false_values = ["false", "0", "no", "n"]
+
+    if value.lower() in true_values:
+        return True
+    elif value.lower() in false_values:
+        return False
+    raise EnvironmentVarValueError(f"Invalid boolean value: {value}")
+
+
+def interpret_int_env(value: str) -> int:
+    """Interpret an integer environment variable value.
+
+    Args:
+        value: The environment variable value.
+
+    Returns:
+        The interpreted value.
+
+    Raises:
+        EnvironmentVarValueError: If the value is invalid.
+    """
+    try:
+        return int(value)
+    except ValueError as ve:
+        raise EnvironmentVarValueError(f"Invalid integer value: {value}") from ve
+
+
+def interpret_path_env(value: str) -> Path:
+    """Interpret a path environment variable value.
+
+    Args:
+        value: The environment variable value.
+
+    Returns:
+        The interpreted value.
+
+    Raises:
+        EnvironmentVarValueError: If the path does not exist.
+    """
+    path = Path(value)
+    if not path.exists():
+        raise EnvironmentVarValueError(f"Path does not exist: {path}")
+    return path
+
+
+def interpret_env_var_value(value: str, field: dataclasses.Field) -> Any:
+    """Interpret an environment variable value based on the field type.
+
+    Args:
+        value: The environment variable value.
+        field: The field.
+
+    Returns:
+        The interpreted value.
+
+    Raises:
+        ValueError: If the value is invalid.
+    """
+    field_type = value_inside_optional(field.type)
+
+    if field_type is bool:
+        return interpret_boolean_env(value)
+    elif field_type is str:
+        return value
+    elif field_type is int:
+        return interpret_int_env(value)
+    elif field_type is Path:
+        return interpret_path_env(value)
+
+    else:
+        raise ValueError(
+            f"Invalid type for environment variable {field.name}: {field_type}. This is probably an issue in Reflex."
+        )
+
+
+@dataclasses.dataclass(init=False)
+class EnvironmentVariables:
+    """Environment variables class to instantiate environment variables."""
+
+    # Whether to use npm over bun to install frontend packages.
+    REFLEX_USE_NPM: bool = False
+
+    # The npm registry to use.
+    NPM_CONFIG_REGISTRY: Optional[str] = None
+
+    # Whether to use Granian for the backend. Otherwise, use Uvicorn.
+    REFLEX_USE_GRANIAN: bool = False
+
+    # The username to use for authentication on python package repository. Username and password must both be provided.
+    TWINE_USERNAME: Optional[str] = None
+
+    # The password to use for authentication on python package repository. Username and password must both be provided.
+    TWINE_PASSWORD: Optional[str] = None
+
+    # Whether to use the system installed bun. If set to false, bun will be bundled with the app.
+    REFLEX_USE_SYSTEM_BUN: bool = False
+
+    # Whether to use the system installed node and npm. If set to false, node and npm will be bundled with the app.
+    REFLEX_USE_SYSTEM_NODE: bool = False
+
+    # The working directory for the next.js commands.
+    REFLEX_WEB_WORKDIR: Path = Path(constants.Dirs.WEB)
+
+    # Path to the alembic config file
+    ALEMBIC_CONFIG: Path = Path(constants.ALEMBIC_CONFIG)
+
+    # Disable SSL verification for HTTPX requests.
+    SSL_NO_VERIFY: bool = False
+
+    # The directory to store uploaded files.
+    REFLEX_UPLOADED_FILES_DIR: Path = Path(constants.Dirs.UPLOADED_FILES)
+
+    # Whether to use seperate processes to compile the frontend and how many. If not set, defaults to thread executor.
+    REFLEX_COMPILE_PROCESSES: Optional[int] = None
+
+    # Whether to use seperate threads to compile the frontend and how many. Defaults to `min(32, os.cpu_count() + 4)`.
+    REFLEX_COMPILE_THREADS: Optional[int] = None
+
+    # The directory to store reflex dependencies.
+    REFLEX_DIR: Path = Path(constants.Reflex.DIR)
+
+    # Whether to print the SQL queries if the log level is INFO or lower.
+    SQLALCHEMY_ECHO: bool = False
+
+    # Whether to ignore the redis config error. Some redis servers only allow out-of-band configuration.
+    REFLEX_IGNORE_REDIS_CONFIG_ERROR: bool = False
+
+    # Whether to skip purging the web directory in dev mode.
+    REFLEX_PERSIST_WEB_DIR: bool = False
+
+    # The reflex.build frontend host.
+    REFLEX_BUILD_FRONTEND: str = constants.Templates.REFLEX_BUILD_FRONTEND
+
+    # The reflex.build backend host.
+    REFLEX_BUILD_BACKEND: str = constants.Templates.REFLEX_BUILD_BACKEND
+
+    def __init__(self):
+        """Initialize the environment variables."""
+        type_hints = get_type_hints(type(self))
+
+        for field in dataclasses.fields(self):
+            raw_value = os.getenv(field.name, None)
+
+            field.type = type_hints.get(field.name) or field.type
+
+            value = (
+                interpret_env_var_value(raw_value, field)
+                if raw_value is not None
+                else get_default_value_for_field(field)
+            )
+
+            setattr(self, field.name, value)
+
+
+environment = EnvironmentVariables()
+
+
 class Config(Base):
     """The config defines runtime settings for the app.