sshBasedApi/sshWrapper.sh at master · aitorpazos/sshBasedApi · GitHub

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#!/bin/bash
set -euo pipefail

# sshWrapper.sh — Entrypoint for the SSH-based API container.
# Manages the sshd process lifecycle with signal handling for graceful
# restart (USR1) and shutdown (SIGINT/SIGTERM).

SSHD_KILL_GRACE_TIME=3
RUNNING_SSHD=""

restart_sshd() {
    echo "USR1 signal received. Restarting SSH server"
    if [ -n "${RUNNING_SSHD}" ]; then
        kill "${RUNNING_SSHD}" 2>/dev/null || true
        sleep "${SSHD_KILL_GRACE_TIME}"
        kill -9 "${RUNNING_SSHD}" 2>/dev/null || true
    fi

    /usr/sbin/sshd -D -e &
    RUNNING_SSHD=$!
}

exit_wrapper() {
    echo "Quit signal received. Exiting"
    if [ -n "${RUNNING_SSHD}" ]; then
        kill "${RUNNING_SSHD}" 2>/dev/null || true
        sleep "${SSHD_KILL_GRACE_TIME}"
        kill -9 "${RUNNING_SSHD}" 2>/dev/null || true
    fi

    exit 0
}

trap "restart_sshd" USR1
trap "exit_wrapper" SIGINT SIGTERM

/usr/sbin/sshd -D -e &
RUNNING_SSHD=$!

# Keep the wrapper alive so signals can be caught.
while true; do
    sleep 5
done