Add redbot-update command for updating Red (#6734)

redbot/_update/runner.py

@@ -0,0 +1,119 @@
+import enum
+import dataclasses
+import json
+import os
+import sys
+from pathlib import Path
+from typing import Any, ClassVar, Dict, Iterable, NoReturn, Optional, Tuple, Union
+
+from . import cmd, common
+
+_RUNNER_DIR = Path(os.environ.get(common.RUNNER_DIR_ENV_VAR, ""))
+
+
+class RequestType(enum.Enum):
+    exec = "exec"
+    spawn_command = "spawn_command"
+
+
+@dataclasses.dataclass(frozen=True)
+class RequestInput:
+    request_type: ClassVar[RequestType]
+    request_new_python_exe: str
+    request_new_start_args: Tuple[str, ...]
+    request_set_env_vars: Dict[str, Optional[str]]
+
+
+@dataclasses.dataclass(frozen=True)
+class RequestOutput:
+    request_type: RequestType
+
+
+@dataclasses.dataclass(frozen=True)
+class ExecRequestInput(RequestInput):
+    request_type: ClassVar = RequestType.exec
+
+
+@dataclasses.dataclass(frozen=True)
+class ExecRequestOutput(RequestOutput):
+    pass
+
+
+@dataclasses.dataclass(frozen=True)
+class SpawnProcessRequestInput(RequestInput):
+    request_type: ClassVar = RequestType.spawn_command
+    command: str
+    args: Tuple[str, ...]
+    env: Optional[Dict[str, str]]
+
+
+@dataclasses.dataclass(frozen=True)
+class SpawnProcessRequestOutput(RequestOutput):
+    exit_code: int
+    exited: bool
+    pid: int
+    sys: Any
+    sys_usage: Dict[str, Any]
+    system_time: int
+    user_time: int
+
+
+def make_request(request: RequestInput) -> NoReturn:
+    with open(_RUNNER_DIR / "request_input.json", "w", encoding="utf-8") as fp:
+        data = dataclasses.asdict(request)
+        data["request_type"] = request.request_type.value
+        json.dump(data, fp)
+    raise SystemExit(3)
+
+
+def get_request_output() -> Union[ExecRequestOutput, SpawnProcessRequestOutput]:
+    with open(_RUNNER_DIR / "request_output.json", encoding="utf-8") as fp:
+        data = json.load(fp)
+        request_type = RequestType(data.pop("request_type"))
+        if request_type == RequestType.exec:
+            return ExecRequestOutput(request_type=request_type)
+        elif request_type == RequestType.spawn_command:
+            return SpawnProcessRequestOutput(request_type=request_type, **data)
+        raise RuntimeError("unreachable code")
+
+
+def make_spawn_process_request(
+    command: str,
+    *args: str,
+    env: Optional[Dict[str, str]] = None,
+    new_start_args: Iterable[str],
+    new_python_exe: str = sys.executable,
+    set_env_vars: Optional[Dict[str, Optional[str]]] = None,
+) -> NoReturn:
+    if set_env_vars is None:
+        set_env_vars = {}
+    debug_args = (cmd.arg_names.DEBUG,) * common.get_log_cli_level()
+    request = SpawnProcessRequestInput(
+        request_new_python_exe=new_python_exe,
+        request_new_start_args=("-m", "redbot._update.internal", *debug_args, *new_start_args),
+        request_set_env_vars=set_env_vars,
+        command=command,
+        args=args,
+        env=env,
+    )
+    make_request(request)
+
+
+def make_exec_request(
+    new_python_exe: str,
+    *new_start_args: str,
+    set_env_vars: Optional[Dict[str, Optional[str]]] = None,
+) -> NoReturn:
+    if set_env_vars is None:
+        set_env_vars = {}
+    debug_args = (cmd.arg_names.DEBUG,) * common.get_log_cli_level()
+    request = ExecRequestInput(
+        request_new_python_exe=new_python_exe,
+        request_new_start_args=("-m", "redbot._update.internal", *debug_args, *new_start_args),
+        request_set_env_vars=set_env_vars,
+    )
+    make_request(request)
+
+
+def get_wrapper_executable() -> Path:
+    return Path(os.environ[common.RUNNER_WRAPPER_EXE_ENV_VAR])