jw-pkg/src/python/jw/pkg/lib/ec/Local.py

# -*- coding: utf-8 -*-

import os, sys, subprocess, asyncio

from ..util import run_cmd
from ..ExecContext import ExecContext as Base
from ..ExecContext import Result

from ..log import *
from ..util import pretty_cmd

class Local(Base):

    def __init__(self, uri='local', *args, **kwargs) -> None:
        super().__init__(uri, *args, **kwargs)

    async def _run(
        self,
        args: list[str],
        wd: str|None,
        throw: bool,
        verbose: bool,
        cmd_input: str|None,
        env: dict[str, str]|None,
        title: str,
        output_encoding: str|None,  # None => unchanged; "bytes" => return raw bytes
    ) -> Result:

        want_bytes = (output_encoding == "bytes")

        def __log(prio, *args, verbose=verbose):
            if verbose:
                log(prio, "|", *args)

        def __check_exit_code(code: int, stdout=None, stderr=None):
            if code == 0:
                return
            if (throw or verbose):
                msg = f'Command exited with status {code}: {pretty_cmd(args, wd)}'
                if stderr:
                    msg += ': ' + stderr.strip()
                if throw:
                    raise RuntimeError(msg)

        def __make_pty_reader(collector: list[bytes], enc_for_verbose: str):
            def _read(fd):
                ret = os.read(fd, 1024)
                if not ret:
                    return ret
                collector.append(ret)
                return ret
            return _read

        interactive = (
               cmd_input == "mode:interactive"
            or (cmd_input == "mode:auto" and sys.stdin.isatty())
        )

        if verbose:
            delim_len = 120
            delim = title if title is not None else f'---- Running {pretty_cmd(args, wd)} -'
            if interactive:
                log(NOTICE, delim)
            else:
                delim += '-' * max(0, delim_len - len(delim))
                log(NOTICE, ',' + delim + ' >')

        cwd: str|None = None
        if wd is not None:
            cwd = os.getcwd()
            os.chdir(wd)

        try:

            # -- interactive mode

            if interactive:

                import pty

                stdout_chunks_b: list[bytes] = []

                enc_for_verbose = (
                    (sys.stdout.encoding or "utf-8")
                    if output_encoding in (None, "bytes")
                    else output_encoding
                )

                reader = __make_pty_reader(stdout_chunks_b, enc_for_verbose)

                def _spawn():
                    # Apply env in PTY mode by temporarily updating os.environ around spawn.
                    if env:
                        old_env = os.environ.copy()
                        try:
                            os.environ.update(env)
                            return pty.spawn(args, master_read=reader)
                        finally:
                            os.environ.clear()
                            os.environ.update(old_env)
                    return pty.spawn(args, master_read=reader)

                exit_code = await asyncio.to_thread(_spawn)
                __check_exit_code(exit_code)

                # PTY merges stdout/stderr
                stdout_b = b"".join(stdout_chunks_b) if stdout_chunks_b else None
                if want_bytes:
                    return stdout_b, None, exit_code

                stdout_dec_enc = (sys.stdout.encoding or "utf-8") if output_encoding is None else output_encoding
                stdout_s = stdout_b.decode(stdout_dec_enc, errors="replace") if stdout_b is not None else None
                return stdout_s, None, exit_code

            # -- non-interactive mode
            stdin = (
                asyncio.subprocess.DEVNULL
                if cmd_input is None
                else asyncio.subprocess.PIPE
            )

            proc = await asyncio.create_subprocess_exec(
                *args,
                stdin=stdin,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
                env=env,
            )

            stdout_parts_b: list[bytes] = []
            stderr_parts_b: list[bytes] = []

            # -- decoding for verbose output in pipe mode
            if output_encoding is None or want_bytes:
                stdout_log_enc = sys.stdout.encoding or "utf-8"
                stderr_log_enc = sys.stderr.encoding or "utf-8"
            else:
                stdout_log_enc = output_encoding
                stderr_log_enc = output_encoding

            async def read_stream(stream, prio, collector: list[bytes], log_enc: str):
                buf = b""
                while True:
                    chunk = await stream.read(4096)
                    if not chunk:
                        break
                    collector.append(chunk)
                    if verbose:
                        buf += chunk
                        while b"\n" in buf:
                            line, buf = buf.split(b"\n", 1)
                            __log(prio, line.decode(log_enc, errors="replace"))
                if verbose and buf:
                    # flush trailing partial line (no newline)
                    __log(prio, buf.decode(log_enc, errors="replace"))

            tasks = [
                asyncio.create_task(
                    read_stream(proc.stdout, NOTICE, stdout_parts_b, stdout_log_enc)
                ),
                asyncio.create_task(
                    read_stream(proc.stderr, ERR, stderr_parts_b, stderr_log_enc)
                ),
            ]

            if stdin is asyncio.subprocess.PIPE:
                proc.stdin.write(cmd_input.encode(sys.stdout.encoding or "utf-8"))
                await proc.stdin.drain()
                proc.stdin.close()

            exit_code = await proc.wait()
            await asyncio.gather(*tasks)
            if want_bytes:
                __check_exit_code(exit_code)

            stdout_b = b"".join(stdout_parts_b) if stdout_parts_b else None
            stderr_b = b"".join(stderr_parts_b) if stderr_parts_b else None

            if want_bytes:
                return stdout_b, stderr_b, exit_code

            if output_encoding is None:
                stdout_dec_enc = sys.stdout.encoding or "utf-8"
                stderr_dec_enc = sys.stderr.encoding or "utf-8"
            else:
                stdout_dec_enc = output_encoding
                stderr_dec_enc = output_encoding

            stdout_s = stdout_b.decode(stdout_dec_enc, errors="replace") if stdout_b is not None else None
            stderr_s = stderr_b.decode(stderr_dec_enc, errors="replace") if stderr_b is not None else None

            if not want_bytes:
                __check_exit_code(exit_code, stdout=stdout_s, stderr=stderr_s)

            return stdout_s, stderr_s, exit_code

        finally:
            if cwd is not None:
                os.chdir(cwd)
            if verbose and not interactive:
                log(NOTICE, '`' + delim + ' <')

    async def _sudo(self, cmd: list[str], mod_env: dict[str, str], opts: list[str], verbose: bool) -> Result:
        env: dict[str, str]|None = None
        cmd_input: str|None = None
        if mod_env:
            env = os.environ.copy()
            env.update(mod_env)
        cmdline = []
        if os.getuid() != 0:
            cmdline.append('/usr/bin/sudo')
            if env is not None:
                cmdline.append('--preserve-env=' + ','.join(mod_env.keys()))
            cmdline.extend(opts)
        cmdline.extend(cmd)
        if self.interactive:
            cmd_input = "mode:interactive"
        # Need to call the base class function, because _run() needs more
        # parameters than we have values for
        return await self.run(cmdline, throw=True, verbose=verbose, env=env, cmd_input=cmd_input)