dsh 0.2.0-rc.2: in-container update (experimental channel), path-agnostic compose, upstream patches adapted to 0.1.x/0.2.x

upstream/container/control-plane/services/management/terminal/pty-helper.py

@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+
+import base64
+import fcntl
+import json
+import os
+import pty
+import select
+import signal
+import struct
+import sys
+import termios
+
+
+def emit(value):
+    sys.stdout.write(json.dumps(value, separators=(",", ":")) + "\n")
+    sys.stdout.flush()
+
+
+def resize(master, cols, rows):
+    fcntl.ioctl(master, termios.TIOCSWINSZ, struct.pack("HHHH", rows, cols, 0, 0))
+
+
+def write_all(target, data):
+    remaining = memoryview(data)
+    while remaining:
+        written = os.write(target, remaining)
+        remaining = remaining[written:]
+
+
+def terminate(pid, requested_signal):
+    try:
+        os.killpg(pid, requested_signal)
+    except ProcessLookupError:
+        return
+    except PermissionError:
+        os.kill(pid, requested_signal)
+
+
+def main():
+    if len(sys.argv) != 4:
+        raise RuntimeError("usage: pty-helper.py <cwd> <cols> <rows>")
+    cwd = sys.argv[1]
+    cols = int(sys.argv[2])
+    rows = int(sys.argv[3])
+    pid, master = pty.fork()
+    if pid == 0:
+        os.chdir(cwd)
+        os.umask(0o002)
+        os.execvpe("/bin/bash", ["/bin/bash", "-i"], os.environ)
+    def stop_child(received_signal, _frame):
+        terminate(pid, signal.SIGTERM if received_signal in (signal.SIGINT, signal.SIGTERM) else received_signal)
+    signal.signal(signal.SIGINT, stop_child)
+    signal.signal(signal.SIGTERM, stop_child)
+    resize(master, cols, rows)
+    stdin_fd = sys.stdin.fileno()
+    stdin_buffer = b""
+    stdin_open = True
+    while True:
+        readable, _, _ = select.select([master] + ([stdin_fd] if stdin_open else []), [], [], 0.25)
+        if master in readable:
+            try:
+                data = os.read(master, 16384)
+            except OSError:
+                data = b""
+            if not data:
+                break
+            emit({"type": "output", "data": base64.b64encode(data).decode("ascii")})
+        if stdin_open and stdin_fd in readable:
+            data = os.read(stdin_fd, 65536)
+            if not data:
+                stdin_open = False
+                terminate(pid, signal.SIGHUP)
+            else:
+                stdin_buffer += data
+                while b"\n" in stdin_buffer:
+                    line, stdin_buffer = stdin_buffer.split(b"\n", 1)
+                    command = json.loads(line.decode("utf-8"))
+                    command_type = command.get("type")
+                    if command_type == "input":
+                        write_all(master, base64.b64decode(command["data"], validate=True))
+                    elif command_type == "resize":
+                        resize(master, int(command["cols"]), int(command["rows"]))
+                    elif command_type == "signal":
+                        terminate(pid, int(command["signal"]))
+                    else:
+                        raise RuntimeError("unknown PTY command")
+        finished, status = os.waitpid(pid, os.WNOHANG)
+        if finished == pid:
+            if os.WIFEXITED(status):
+                emit({"type": "exit", "code": os.WEXITSTATUS(status), "signal": None})
+            else:
+                emit({"type": "exit", "code": None, "signal": os.WTERMSIG(status)})
+            os.close(master)
+            return
+    _, status = os.waitpid(pid, 0)
+    if os.WIFEXITED(status):
+        emit({"type": "exit", "code": os.WEXITSTATUS(status), "signal": None})
+    else:
+        emit({"type": "exit", "code": None, "signal": os.WTERMSIG(status)})
+    os.close(master)
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except Exception as error:
+        emit({"type": "error", "message": str(error)})
+        sys.exit(1)