Nginx 应用部署实战

本文提供一份完整的 Nginx 应用部署手册，涵盖从安装 Nginx 到配置反向代理、SSL 证书、SELinux 策略和日志轮转的全过程。适用于将 Nginx 作为前端代理转发到 Node.js、Python (Gunicorn/uWSGI) 或 PHP-FPM 后端的典型场景。

前置条件

服务器已完成新机上线基线清单
已有域名并解析到服务器 IP
后端应用已部署并可在本地端口（如 127.0.0.1:3000）上运行

第 1 步：安装 Nginx

使用 AppStream 仓库

dnf install -y nginx

使用 Nginx 官方仓库（推荐获取最新稳定版）

cat > /etc/yum.repos.d/nginx.repo << 'EOF'
[nginx-stable]
name=nginx stable repo
baseurl=https://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true
EOF

dnf install -y nginx

启动并启用服务：

systemctl enable --now nginx

# 验证
systemctl status nginx
curl -I http://localhost

第 2 步：配置 Server Block

移除默认配置并创建应用专属配置：

# 备份默认配置
mv /etc/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf.bak

创建应用配置文件 /etc/nginx/conf.d/myapp.conf：

# 上游后端定义
upstream myapp_backend {
    server 127.0.0.1:3000;
    keepalive 32;
}

server {
    listen 80;
    server_name example.com www.example.com;

    # 访问日志与错误日志
    access_log /var/log/nginx/myapp_access.log;
    error_log  /var/log/nginx/myapp_error.log;

    # 安全头
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    # 静态文件（如果有）
    location /static/ {
        alias /var/www/myapp/static/;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }

    # 反向代理到后端
    location / {
        proxy_pass http://myapp_backend;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Connection "";

        # 超时设置
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
    }

    # 健康检查端点
    location /health {
        proxy_pass http://myapp_backend/health;
        access_log off;
    }
}

针对不同后端的配置

PHP-FPM 后端：

upstream php_backend {
    server unix:/run/php-fpm/www.sock;
}

location ~ \.php$ {
    fastcgi_pass php_backend;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
}

Python (Gunicorn) 后端：

upstream gunicorn_backend {
    server unix:/run/gunicorn/myapp.sock;
}

location / {
    proxy_pass http://gunicorn_backend;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
}

测试并重载配置：

nginx -t
systemctl reload nginx

第 3 步：SSL 证书（Let’s Encrypt + Certbot）

3.1 安装 Certbot

dnf install -y epel-release
dnf install -y certbot python3-certbot-nginx

3.2 申请证书

certbot --nginx -d example.com -d www.example.com

Certbot 会自动修改 Nginx 配置以启用 SSL。验证生成的配置：

nginx -t

3.3 自动续期

Certbot 安装后会自动创建 systemd timer：

# 查看续期定时器
systemctl list-timers | grep certbot

# 手动测试续期（dry-run）
certbot renew --dry-run

3.4 SSL 优化配置

在 /etc/nginx/conf.d/ssl-params.conf 中添加全局 SSL 优化：

# SSL 协议和密码套件
ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384';
ssl_prefer_server_ciphers on;

# SSL 会话缓存
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 1d;
ssl_session_tickets off;

# OCSP Stapling
ssl_stapling on;
ssl_stapling_verify on;
resolver 8.8.8.8 1.1.1.1 valid=300s;
resolver_timeout 5s;

# HSTS
add_header Strict-Transport-Security "max-age=63072000; includeSubDomains" always;

第 4 步：SELinux 策略配置

SELinux 默认不允许 Nginx 向网络后端发起连接。必须配置相应布尔值：

# 允许 Nginx 连接到网络后端
setsebool -P httpd_can_network_connect 1

# 如果 Nginx 需要访问用户主目录下的内容
setsebool -P httpd_enable_homedirs 1

# 如果 Nginx 需要连接数据库
setsebool -P httpd_can_network_connect_db 1

如果静态文件位于非标准路径，需要设置 SELinux 上下文：

# 设置 Web 内容标签
semanage fcontext -a -t httpd_sys_content_t "/var/www/myapp(/.*)?"
restorecon -Rv /var/www/myapp

如果 Nginx 监听非标准端口：

# 添加端口标签（例如端口 8080）
semanage port -a -t http_port_t -p tcp 8080

排查 SELinux 拒绝日志：

# 查看拒绝记录
ausearch -m AVC -ts recent

# 自动生成策略建议
audit2why < /var/log/audit/audit.log

第 5 步：防火墙配置

# 开放 HTTP 和 HTTPS
firewall-cmd --permanent --add-service=http
firewall-cmd --permanent --add-service=https

# 重新加载
firewall-cmd --reload

# 验证
firewall-cmd --list-services

第 6 步：后端应用的 Systemd 服务

为后端应用创建 systemd 服务单元，以 Node.js 应用为例：

cat > /etc/systemd/system/myapp.service << 'EOF'
[Unit]
Description=My Application
Documentation=https://example.com/docs
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=appuser
Group=appuser
WorkingDirectory=/opt/myapp
ExecStart=/usr/bin/node /opt/myapp/server.js
Restart=on-failure
RestartSec=5
StartLimitInterval=60
StartLimitBurst=3

# 环境变量
Environment=NODE_ENV=production
Environment=PORT=3000
EnvironmentFile=-/opt/myapp/.env

# 安全加固
NoNewPrivileges=true
ProtectSystem=strict
ProtectHome=true
ReadWritePaths=/opt/myapp/data /var/log/myapp
PrivateTmp=true

# 资源限制：MemoryMax 是运维参数，按实测常驻内存设定（示例 1G，不是最低要求）
LimitNOFILE=65536
MemoryMax=1G

# 日志
StandardOutput=journal
StandardError=journal
SyslogIdentifier=myapp

[Install]
WantedBy=multi-user.target
EOF

Gunicorn 示例：

cat > /etc/systemd/system/myapp.service << 'EOF'
[Unit]
Description=Gunicorn Application Server
After=network-online.target

[Service]
Type=notify
User=appuser
Group=appuser
WorkingDirectory=/opt/myapp
ExecStart=/opt/myapp/venv/bin/gunicorn \
    --workers 4 \
    --bind unix:/run/gunicorn/myapp.sock \
    --access-logfile /var/log/myapp/access.log \
    --error-logfile /var/log/myapp/error.log \
    wsgi:app
ExecReload=/bin/kill -s HUP $MAINPID
Restart=on-failure
RuntimeDirectory=gunicorn

[Install]
WantedBy=multi-user.target
EOF

启动服务：

# 创建应用用户
useradd -r -s /sbin/nologin appuser

# 设置目录权限
chown -R appuser:appuser /opt/myapp

systemctl daemon-reload
systemctl enable --now myapp

# 验证
systemctl status myapp
curl http://127.0.0.1:3000/health

第 7 步：健康检查

7.1 应用端健康检查

确保后端应用实现了 /health 端点，返回当前服务状态。最小示例（Node.js）：

app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'ok',
    uptime: process.uptime(),
    timestamp: Date.now()
  });
});

7.2 外部监控脚本

创建一个简单的健康检查脚本：

cat > /usr/local/bin/health-check.sh << 'SCRIPT'
#!/bin/bash
URL="http://127.0.0.1/health"
HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" "$URL" --max-time 5)

if [ "$HTTP_CODE" != "200" ]; then
    echo "[$(date)] Health check failed: HTTP $HTTP_CODE" >> /var/log/health-check.log
    systemctl restart myapp
    systemctl reload nginx
fi
SCRIPT

chmod +x /usr/local/bin/health-check.sh

添加定时检查：

cat > /etc/cron.d/health-check << 'EOF'
*/5 * * * * root /usr/local/bin/health-check.sh
EOF

7.3 端到端验证

部署完成后，进行完整的端到端测试：

# HTTP 到 HTTPS 重定向
curl -I http://example.com

# HTTPS 正常响应
curl -I https://example.com

# 后端健康检查
curl https://example.com/health

# SSL 证书信息
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates

第 8 步：日志轮转

Nginx 的默认日志轮转通常已配置。为应用自定义日志添加规则：

cat > /etc/logrotate.d/myapp << 'EOF'
/var/log/myapp/*.log {
    daily
    missingok
    rotate 14
    compress
    delaycompress
    notifempty
    create 0640 appuser appuser
    sharedscripts
    postrotate
        /bin/systemctl reload myapp > /dev/null 2>&1 || true
    endscript
}

/var/log/nginx/myapp_*.log {
    daily
    missingok
    rotate 30
    compress
    delaycompress
    notifempty
    create 0640 nginx adm
    sharedscripts
    postrotate
        /bin/kill -USR1 $(cat /run/nginx.pid 2>/dev/null) 2>/dev/null || true
    endscript
}
EOF

测试配置：

logrotate -d /etc/logrotate.d/myapp

部署检查清单

序号	检查项	验证命令	预期结果
1	Nginx 运行	`systemctl status nginx`	active
2	配置语法	`nginx -t`	syntax is ok
3	SSL 证书	`certbot certificates`	有效且未过期
4	SELinux 布尔值	`getsebool httpd_can_network_connect`	on
5	防火墙	`firewall-cmd --list-services`	http https
6	后端服务	`systemctl status myapp`	active
7	健康检查	`curl http://127.0.0.1/health`	200 OK
8	HTTPS 访问	`curl -I https://example.com`	200 OK
9	日志轮转	`logrotate -d /etc/logrotate.d/myapp`	无错误

故障排查

问题	排查步骤
502 Bad Gateway	检查后端服务是否运行；检查 SELinux `httpd_can_network_connect`；查看 `/var/log/nginx/myapp_error.log`
403 Forbidden	检查文件权限；检查 SELinux 上下文 `ls -Z`；运行 `restorecon`
SSL 证书过期	运行 `certbot renew`；检查 systemd timer `systemctl status certbot-renew.timer`
连接被拒	检查 `firewall-cmd --list-all`；确认 Nginx 监听正确端口 `ss -tlnp`