اصول Automation در DevOps

1# فقط وابسته به زمان اجرا — امکان دارد در روزهای بعد overwrite کند 
2backup_file="backup-$(date +%H%M).tar.gz"
3tar -czf "$backup_file" /var/www

1# نام فایل از timestamp کامل ساخته می‌شود
2backup_file="backup-$(date +%Y%m%d-%H%M%S).tar.gz"
3tar -czf "/backups/$backup_file" /var/www || exit 1
4echo "Backup created: $backup_file"

 1#!/usr/bin/env bash
 2set -euo pipefail
 3
 4# چک کردن ابزارهای مورد نیاز
 5for cmd in git systemctl nginx; do
 6  if ! command -v "$cmd" &>/dev/null; then
 7    echo "ERROR: $cmd not found" >&2
 8    exit 1
 9  fi
10done
11
12# استفاده از مسیر مطلق
13APP_DIR="/opt/myapp"
14cd "$APP_DIR" || exit 1
15
16# محیط صریح
17export PATH="/usr/local/bin:/usr/bin:/bin"

1# هر بار یک خط اضافه می‌شود
2echo "nameserver 8.8.8.8" >> /etc/resolv.conf

1# فقط اگر وجود نداشته باشد، اضافه می‌شود
2if ! grep -q "nameserver 8.8.8.8" /etc/resolv.conf; then
3  echo "nameserver 8.8.8.8" >> /etc/resolv.conf
4fi

 1#!/usr/bin/env bash
 2set -euo pipefail
 3
 4# ایجاد کاربر — فقط اگر وجود نداشته باشد
 5if ! id myuser &>/dev/null; then
 6  useradd -r -s /usr/sbin/nologin myuser
 7  echo "User created"
 8else
 9  echo "User already exists"
10fi
11
12# ایجاد دایرکتوری — idempotent است
13mkdir -p /opt/myapp/data
14
15# نصب پکیج — package manager خودش idempotent است
16apt-get install -y nginx

 1#!/usr/bin/env bash
 2set -euo pipefail
 3
 4MAX_RETRIES=3
 5RETRY_DELAY=5
 6
 7download_with_retry() {
 8  local url="$1"
 9  local output="$2"
10  local attempt=1
11
12  while [ $attempt -le $MAX_RETRIES ]; do
13    echo "Attempt $attempt of $MAX_RETRIES"
14    
15    if curl -fsSL -o "$output" "$url"; then
16      echo "Download successful"
17      return 0
18    fi
19    
20    echo "Download failed, retrying in ${RETRY_DELAY}s..."
21    sleep $RETRY_DELAY
22    attempt=$((attempt + 1))
23  done
24
25  echo "ERROR: Download failed after $MAX_RETRIES attempts" >&2
26  return 1
27}
28
29# استفاده
30download_with_retry "https://example.com/file.tar.gz" "/tmp/file.tar.gz"

 1#!/usr/bin/env bash
 2set -euo pipefail
 3
 4deploy_new_version() {
 5  local backup_dir="/backups/app-$(date +%s)"
 6  
 7  # گرفتن backup قبل از تغییر
 8  echo "Creating backup..."
 9  cp -a /opt/myapp "$backup_dir"
10  
11  # متوقف کردن سرویس
12  systemctl stop myapp
13  
14  # تلاش برای deploy نسخه جدید
15  if ! git pull origin main; then
16    echo "ERROR: Git pull failed, rolling back..." >&2
17    rm -rf /opt/myapp
18    mv "$backup_dir" /opt/myapp
19    systemctl start myapp
20    exit 1
21  fi
22  
23  # اگر service بالا نیامد، rollback
24  systemctl start myapp
25  sleep 2
26  
27  if ! systemctl is-active --quiet myapp; then
28    echo "ERROR: Service failed to start, rolling back..." >&2
29    rm -rf /opt/myapp
30    mv "$backup_dir" /opt/myapp
31    systemctl start myapp
32    exit 1
33  fi
34  
35  echo "Deployment successful"
36  rm -rf "$backup_dir"
37}
38
39deploy_new_version

1#!/bin/bash
2cd /var/www
3rm -rf *
4git clone https://github.com/user/repo.git .
5npm install
6npm run build
7service apache2 restart

 1#!/usr/bin/env bash
 2set -euo pipefail
 3
 4REPO_URL="https://github.com/user/repo.git"
 5DEPLOY_DIR="/var/www"
 6
 7# Check dependencies
 8for cmd in git npm; do
 9  command -v "$cmd" >/dev/null || { echo "ERROR: $cmd not found" >&2; exit 1; }
10done
11
12# Backup before deploy
13backup_dir="/backups/www-$(date +%s)"
14mkdir -p "$(dirname "$backup_dir")"
15cp -a "$DEPLOY_DIR" "$backup_dir"
16
17cd "$DEPLOY_DIR" || exit 1
18
19# Idempotent git pull
20if [ -d .git ]; then
21  git pull origin main
22else
23  git clone "$REPO_URL" .
24fi
25
26npm install
27npm run build
28
29# Restart and verify
30systemctl restart apache2
31sleep 2
32
33if systemctl is-active --quiet apache2; then
34  echo "Deployment successful"
35  rm -rf "$backup_dir"
36else
37  echo "ERROR: Apache failed to start, rolling back" >&2
38  rm -rf "$DEPLOY_DIR"
39  mv "$backup_dir" "$DEPLOY_DIR"
40  systemctl start apache2
41  exit 1
42fi