さくらのVPS入門 CentOSの基本設定とNginxのインストール 参考資料

フィードバック等

SSHでログイン

手元のMacにて

ssh root@IPアドレス

この時,仮登録完了メールに記載の初期パスワードを利用します.

一般ユーザの作成

VPSのrootユーザにて

useradd admin
passwd admin
usermod -G wheel admin

sudoコマンドの有効化

visudo

105行目の

%wheel  ALL=(ALL)  ALL

の先頭の # を削除します

一般ユーザーでSSHログインしなおす

手元のMacにて

ssh admin@IPアドレス

この時のパスワードは先ほどadminユーザーを作成した時に指定したパスワードを使います

ネットワーク周りのセキュリティ設定

iptables によるIPv4パケットフィルタリング

sudo iptables -N Firewall-Services-INPUT
sudo iptables -A INPUT -j Firewall-Services-INPUT
sudo iptables -A Firewall-Services-INPUT -i lo -j ACCEPT
sudo iptables -A Firewall-Services-INPUT -p icmp --icmp-type any -j ACCEPT
sudo iptables -A Firewall-Services-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
sudo iptables -A Firewall-Services-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
sudo iptables -A Firewall-Services-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
sudo iptables -P INPUT DROP
sudo iptables -P FORWARD DROP
sudo /etc/init.d/iptables save

ip6tables によるIPv6パケットフィルタリング

sudo ip6tables -N Firewall-Services-INPUT
sudo ip6tables -A INPUT -j Firewall-Services-INPUT
sudo ip6tables -A Firewall-Services-INPUT -i lo -j ACCEPT
sudo ip6tables -A Firewall-Services-INPUT -p icmpv6 -j ACCEPT
sudo ip6tables -A Firewall-Services-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
sudo ip6tables -A Firewall-Services-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
sudo ip6tables -A Firewall-Services-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
sudo ip6tables -P INPUT DROP
sudo ip6tables -P FORWARD DROP
sudo /etc/init.d/ip6tables save

(参考) IPv6の無効化

sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0

7行目の IPV6INET="yes"IPV6INET="no" に書き換えます.

sudo service network restart

SSHのセキュリティ向上

rootログインの禁止

sudo vi /etc/ssh/sshd_config

42行目を PermitRootLogin no に書き換えます.

sudo service sshd restart

fail2banのインストール

sudo yum install fail2ban
sudo service fail2ban start

nginxのインストール

sudo vi /etc/yum.repos.d/nginx.repo

テキストファイルの中身を以下の内容にし,保存します.

[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/6/$basearch/
gpgcheck=0
enabled=1
sudo yum -y --enablerepo=nginx install nginx
sudo service nginx start

Nginxのバージョンを隠す

sudo vi /etc/nginx/nginx.conf

最後から4行目あたりに,server_tokens off; を追加します.

sudo nginx -t
sudo service nginx reload

NginxのIPv6有効化

sudo vi /etc/nginx/conf.d/default.conf

3行目に一行追加し,保存します.

    listen       [::]:80;

ファイルのアップロード

SSHを用いてファイルの送受信ができるSFTPが利用できます. Cyberduck等のクライアントアプリケーションを利用すると簡単にファイルの送信ができます.

adminユーザで読み書きができるように,一時的に所有権を変更し,転送後に元にもどします.

sudo chown -R admin /usr/share/nginx/html
sudo chown -R root /usr/share/nginx/html

今回変更したファイル

visudo

## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
##
## Examples are provided at the bottom of the file for collections
## of related commands, which can then be delegated out to particular
## users or groups.
##
## This file must be edited with the 'visudo' command.

## Host Aliases
## Groups of machines. You may prefer to use hostnames (perhaps using
## wildcards for entire domains) or IP addresses instead.
# Host_Alias     FILESERVERS = fs1, fs2
# Host_Alias     MAILSERVERS = smtp, smtp2

## User Aliases
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname
## rather than USERALIAS
# User_Alias ADMINS = jsmith, mikem


## Command Aliases
## These are groups of related commands...

## Networking
# Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, /sbin/mii-tool

## Installation and management of software
# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum

## Services
# Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig

## Updating the locate database
# Cmnd_Alias LOCATE = /usr/bin/updatedb

## Storage
# Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount

## Delegating permissions
# Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp

## Processes
# Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall

## Drivers
# Cmnd_Alias DRIVERS = /sbin/modprobe

# Defaults specification

#
# Disable "ssh hostname sudo <cmd>", because it will show the password in clear.
#         You have to run "ssh -t hostname sudo <cmd>".
#
Defaults    requiretty

#
# Refuse to run if unable to disable echo on the tty. This setting should also be
# changed in order to be able to use sudo without a tty. See requiretty above.
#
Defaults   !visiblepw

#
# Preserving HOME has security implications since many programs
# use it when searching for configuration files. Note that HOME
# is already set when the the env_reset option is enabled, so
# this option is only effective for configurations where either
# env_reset is disabled or HOME is present in the env_keep list.
#
Defaults    always_set_home

Defaults    env_reset
Defaults    env_keep =  "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS"
Defaults    env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"
Defaults    env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"
Defaults    env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"
Defaults    env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"

#
# Adding HOME to env_keep may enable a user to run unrestricted
# commands via sudo.
#
# Defaults   env_keep += "HOME"

Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin

## Next comes the main part: which users can run what software on
## which machines (the sudoers file can be shared between multiple
## systems).
## Syntax:
##
##  user    MACHINE=COMMANDS
##
## The COMMANDS section may have other options added to it.
##
## Allow root to run any commands anywhere
root    ALL=(ALL)   ALL

## Allows members of the 'sys' group to run networking, software,
## service management apps and more.
# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS

## Allows people in group wheel to run all commands
%wheel  ALL=(ALL)   ALL

## Same thing without a password
# %wheel    ALL=(ALL)   NOPASSWD: ALL

## Allows members of the users group to mount and unmount the
## cdrom as root
# %users  ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom

## Allows members of the users group to shutdown this system
# %users  localhost=/sbin/shutdown -h now

## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)
#includedir /etc/sudoers.d

/etc/nginx/nginx.conf

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;
    server_tokens off;

    include /etc/nginx/conf.d/*.conf;
}

/etc/nginx/conf.d/default.conf

server {
    listen       80;
    listen       [::]:80;
    server_name  localhost;

    #charset koi8-r;
    #access_log  /var/log/nginx/log/host.access.log  main;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
    }

    #error_page  404              /404.html;

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ \.php$ {
    #    proxy_pass   http://127.0.0.1;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    #location ~ \.php$ {
    #    root           html;
    #    fastcgi_pass   127.0.0.1:9000;
    #    fastcgi_index  index.php;
    #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
    #    include        fastcgi_params;
    #}

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /\.ht {
    #    deny  all;
    #}
}