Zaxira nusxa, taymerlar va himoya

mkdir -p manba/ichki nusxa
echo "birinchi" > manba/a.txt
echo "ikkinchi" > manba/ichki/b.txt

tar -czf nusxa/zaxira.tar.gz -C manba .
tar -tzf nusxa/zaxira.tar.gz | sort

tar -czf nusxa/zaxira.tar.gz -C manba .
mkdir -p tiklangan
tar -xzf nusxa/zaxira.tar.gz -C tiklangan
find tiklangan -type f | sort

mkdir -p kun1 kun2
rsync -a manba/ kun1/
echo "uchinchi" > manba/c.txt
rsync -a --link-dest=../kun1 manba/ kun2/
[ "$(stat -c %i kun1/a.txt)" = "$(stat -c %i kun2/a.txt)" ] \
    && echo "a.txt - bitta inode, disk joyi ikki marta band emas"
[ -f kun2/c.txt ] && echo "c.txt - yangi fayl, alohida nusxa"

mysqldump --single-transaction --quick --routines \
    --databases softromeda_edu | gzip > /zaxira/baza.sql.gz

cat > zaxira.sh <<'EOF'
#!/bin/bash
set -euo pipefail
umask 077

MANBA="/var/www/sayt"
NUSXA="/zaxira"
QULF="/run/zaxira.pid"

exec > >(systemd-cat -t zaxira -p info) 2>&1

if [ -f "$QULF" ] && kill -0 "$(cat "$QULF")" 2>/dev/null; then
    echo "oldingi nusxa hali ishlayapti - chiqilmoqda"
    exit 0
fi
echo $$ > "$QULF"
trap 'rm -f "$QULF"' EXIT

SANA=$(date +%F)
echo "zaxira boshlandi: $SANA"

nice -n 19 ionice -c 3 \
    tar -czf "$NUSXA/sayt-$SANA.tar.gz" -C "$(dirname "$MANBA")" "$(basename "$MANBA")"

find "$NUSXA" -name 'sayt-*.tar.gz' -mtime +14 -delete

echo "zaxira tugadi: $(du -h "$NUSXA/sayt-$SANA.tar.gz" | cut -f1)"
EOF
chmod 755 zaxira.sh
bash -n zaxira.sh && echo "sintaksis to'g'ri"

rm -f /etc/systemd/system/sr-zaxira.service /etc/systemd/system/sr-zaxira.timer
cat > /etc/systemd/system/sr-zaxira.service <<'EOF'
[Unit]
Description=Softromeda zaxira nusxasi

[Service]
Type=oneshot
ExecStart=/bin/echo "zaxira bajarildi"
Nice=19
IOSchedulingClass=idle
EOF

cat > /etc/systemd/system/sr-zaxira.timer <<'EOF'
[Unit]
Description=Har kuni 03:30 da zaxira

[Timer]
OnCalendar=*-*-* 03:30:00
RandomizedDelaySec=15m
Persistent=true

[Install]
WantedBy=timers.target
EOF
systemctl daemon-reload

systemd-analyze verify /etc/systemd/system/sr-zaxira.timer && echo "taymer to'g'ri"

systemctl show sr-zaxira.timer -p Persistent -p RandomizedDelayUSec

systemd-analyze calendar '*-*-* 03:30:00' | grep 'Normalized'

systemd-analyze calendar daily | grep 'Normalized'

systemctl start sr-zaxira.service
sleep 1
journalctl -u sr-zaxira -n 3 --no-pager -o cat | grep -c 'zaxira bajarildi'

tar -czf nusxa/sinov.tar.gz -C manba .
tar -tzf nusxa/sinov.tar.gz > /dev/null && echo "arxiv butun"
[ "$(stat -c %s nusxa/sinov.tar.gz)" -gt 100 ] && echo "arxiv bo'sh emas"

cat > auth.log <<'EOF'
Sep 10 08:14:02 srv sshd[1201]: Failed password for root from 203.0.113.55 port 41022 ssh2
Sep 10 08:14:05 srv sshd[1203]: Failed password for root from 203.0.113.55 port 41028 ssh2
Sep 10 08:14:09 srv sshd[1205]: Failed password for admin from 203.0.113.55 port 41034 ssh2
Sep 10 08:15:11 srv sshd[1210]: Failed password for husanboy from 198.51.100.7 port 50122 ssh2
Sep 10 08:16:40 srv sshd[1215]: Accepted publickey for husanboy from 198.51.100.7 port 50130 ssh2
EOF
grep 'Failed password' auth.log | awk '{print $(NF-3)}' | sort | uniq -c | sort -rn

sudo apt install fail2ban
sudo tee /etc/fail2ban/jail.local <<'EOF'
[DEFAULT]
bantime  = 1h
findtime = 10m
maxretry = 5
backend  = systemd

[sshd]
enabled = true
EOF
sudo systemctl enable --now fail2ban
sudo fail2ban-client status sshd

cat > nazorat.sh <<'EOF'
#!/bin/bash
set -uo pipefail
CHEGARA=85

df -h -x tmpfs -x devtmpfs --output=pcent,target | tail -n +2 |
while read -r foiz nuqta; do
    son=${foiz%\%}
    if [ "$son" -ge "$CHEGARA" ]; then
        logger -t nazorat -p user.warning "$nuqta ${son}% to'ldi"
    fi
done

if ! systemctl is-system-running --quiet; then
    logger -t nazorat -p user.warning \
        "yiqilgan xizmatlar: $(systemctl --failed --no-legend | wc -l)"
fi
EOF
chmod 755 nazorat.sh
bash -n nazorat.sh && echo "nazorat skripti to'g'ri"