Manjusaka

import time

time.sleep(10000)

#!/bin/bash

python /root/demo1.py

FROM python:3.9

ADD demo1.py /root/demo1.py
ADD demo1.sh /root/demo1.sh

ENTRYPOINT ["bash", "/root/demo1.sh"]

import os
import time

pid = os.fork()
if pid == 0:
    cpid = os.fork()
time.sleep(1000)

FROM python:3.9

RUN wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64
RUN chmod +x /usr/local/bin/dumb-init

ADD demo2.py /root/demo2.py

ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]

CMD ["python", "/root/demo2.py"]

void handle_signal(int signum) {
    DEBUG("Received signal %d.\n", signum);

    if (signal_temporary_ignores[signum] == 1) {
        DEBUG("Ignoring tty hand-off signal %d.\n", signum);
        signal_temporary_ignores[signum] = 0;
    } else if (signum == SIGCHLD) {
        int status, exit_status;
        pid_t killed_pid;
        while ((killed_pid = waitpid(-1, &status, WNOHANG)) > 0) {
            if (WIFEXITED(status)) {
                exit_status = WEXITSTATUS(status);
                DEBUG("A child with PID %d exited with exit status %d.\n", killed_pid, exit_status);
            } else {
                assert(WIFSIGNALED(status));
                exit_status = 128 + WTERMSIG(status);
                DEBUG("A child with PID %d was terminated by signal %d.\n", killed_pid, exit_status - 128);
            }

            if (killed_pid == child_pid) {
                forward_signal(SIGTERM);  // send SIGTERM to any remaining children
                DEBUG("Child exited with status %d. Goodbye.\n", exit_status);
                exit(exit_status);
            }
        }
    } else {
        forward_signal(signum);
        if (signum == SIGTSTP || signum == SIGTTOU || signum == SIGTTIN) {
            DEBUG("Suspending self due to TTY signal.\n");
            kill(getpid(), SIGSTOP);
        }
    }
}

void forward_signal(int signum) {
    signum = translate_signal(signum);
    if (signum != 0) {
        kill(use_setsid ? -child_pid : child_pid, signum);
        DEBUG("Forwarded signal %d to children.\n", signum);
    } else {
        DEBUG("Not forwarding signal %d to children (ignored).\n", signum);
    }
}

import os
import time

pid = os.fork()
time.sleep(1000)

FROM python:3.9

RUN wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64
RUN chmod +x /usr/local/bin/dumb-init

ADD demo3.py /root/demo3.py

ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]

CMD ["python", "/root/demo3.py"]

	while (1) {
		/* Wait for one signal, and forward it */
		if (wait_and_forward_signal(&parent_sigset, child_pid)) {
			return 1;
		}

		/* Now, reap zombies */
		if (reap_zombies(child_pid, &child_exitcode)) {
			return 1;
		}

		if (child_exitcode != -1) {
			PRINT_TRACE("Exiting: child has exited");
			return child_exitcode;
		}
	}

int wait_and_forward_signal(sigset_t const* const parent_sigset_ptr, pid_t const child_pid) {
	siginfo_t sig;

	if (sigtimedwait(parent_sigset_ptr, &sig, &ts) == -1) {
		switch (errno) {
			case EAGAIN:
				break;
			case EINTR:
				break;
			default:
				PRINT_FATAL("Unexpected error in sigtimedwait: '%s'", strerror(errno));
				return 1;
		}
	} else {
		/* There is a signal to handle here */
		switch (sig.si_signo) {
			case SIGCHLD:
				/* Special-cased, as we don't forward SIGCHLD. Instead, we'll
				 * fallthrough to reaping processes.
				 */
				PRINT_DEBUG("Received SIGCHLD");
				break;
			default:
				PRINT_DEBUG("Passing signal: '%s'", strsignal(sig.si_signo));
				/* Forward anything else */
				if (kill(kill_process_group ? -child_pid : child_pid, sig.si_signo)) {
					if (errno == ESRCH) {
						PRINT_WARNING("Child was dead when forwarding signal");
					} else {
						PRINT_FATAL("Unexpected error when forwarding signal: '%s'", strerror(errno));
						return 1;
					}
				}
				break;
		}
	}

	return 0;
}

int reap_zombies(const pid_t child_pid, int* const child_exitcode_ptr) {
	pid_t current_pid;
	int current_status;

	while (1) {
		current_pid = waitpid(-1, &current_status, WNOHANG);

		switch (current_pid) {

			case -1:
				if (errno == ECHILD) {
					PRINT_TRACE("No child to wait");
					break;
				}
				PRINT_FATAL("Error while waiting for pids: '%s'", strerror(errno));
				return 1;

			case 0:
				PRINT_TRACE("No child to reap");
				break;

			default:
				/* A child was reaped. Check whether it's the main one. If it is, then
				 * set the exit_code, which will cause us to exit once we've reaped everyone else.
				 */
				PRINT_DEBUG("Reaped child with pid: '%i'", current_pid);
				if (current_pid == child_pid) {
					if (WIFEXITED(current_status)) {
						/* Our process exited normally. */
						PRINT_INFO("Main child exited normally (with status '%i')", WEXITSTATUS(current_status));
						*child_exitcode_ptr = WEXITSTATUS(current_status);
					} else if (WIFSIGNALED(current_status)) {
						/* Our process was terminated. Emulate what sh / bash
						 * would do, which is to return 128 + signal number.
						 */
						PRINT_INFO("Main child exited with signal (with signal '%s')", strsignal(WTERMSIG(current_status)));
						*child_exitcode_ptr = 128 + WTERMSIG(current_status);
					} else {
						PRINT_FATAL("Main child exited for unknown reason");
						return 1;
					}

					// Be safe, ensure the status code is indeed between 0 and 255.
					*child_exitcode_ptr = *child_exitcode_ptr % (STATUS_MAX - STATUS_MIN + 1);

					// If this exitcode was remapped, then set it to 0.
					INT32_BITFIELD_CHECK_BOUNDS(expect_status, *child_exitcode_ptr);
					if (INT32_BITFIELD_TEST(expect_status, *child_exitcode_ptr)) {
						*child_exitcode_ptr = 0;
					}
				} else if (warn_on_reap > 0) {
					PRINT_WARNING("Reaped zombie process with pid=%i", current_pid);
				}

				// Check if other childs have been reaped.
				continue;
		}

		/* If we make it here, that's because we did not continue in the switch case. */
		break;
	}

	return 0;
}

FROM python:3.9

ADD demo2.py /root/demo2.py
ENV TINI_VERSION v0.19.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
RUN chmod +x /tini

ENTRYPOINT [ "/tini","-s", "-g", "--"]
CMD ["python", "/root/demo2.py"]

import os
import time
import signal
pid = os.fork()
if pid == 0:
    signal.signal(15, lambda _, __: time.sleep(1))
    cpid = os.fork()
time.sleep(1000)

FROM python:3.9

ADD demo4.py /root/demo4.py
ENV TINI_VERSION v0.19.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
RUN chmod +x /tini

ENTRYPOINT [ "/tini","-s", "-g", "--"]
CMD ["python", "/root/demo4.py"]