一、关于Apache2

Ubuntu下安装Apache

可以参考博客里这篇文章
Linux系统下Apache2的安装和配置
安装完成后所有配置文件都在/etc/apache2/目录下

基本原理

apache2在启动的时候自动读取/etc/apache2/apache2.conf文件的配置信息，不同的配置项按功能分布在不同的文件中，然后被Include包含到apache2.conf这个主配置文件中，方便管理。就是说事实上apache2主配置文件只有一个，即apache2.conf，其他的都是被include进来的。可以把所有的配置都放在apache2.conf或者任何一个配置文件中，但是划分到不同文件会让我们管理起来方便很多。

apache2目录结构

├── apache2.conf    全局配置
├── conf-available  可用的配置文件
├── conf-enabled    已启用的配置文件
├── envvars         环境变量
├── magic
├── mods-available  已安装的模块
├── mods-enabled    已启用的模块
├── ports.conf      http服务端口信息
├── sites-available 可用站点信息
├── sites-enabled   已经启用的站点信息，当中的文件是到/etc/apache2/sites-available/ 文件的软连接。

其中，apache2.conf是apache2的主配置文件，包括三个级别的配置

• 控制apache服务器执行过程的全局配置
• 定义主服务或者默认服务器的参数的配置，这些配置会响应virtual host不处理的请求。这类配置也为所有的virtual hosts配置提供默认值。
• virtual hosts相关的配置，使得同一个apache服务进程处理向不同IP地址或者主机名发送的请求

二、Apache2配置介绍

初始情况下，Apache2主配置文件/etc/apache2/apache2.conf。其最后两行为：

# Include the virtual host configurations:
IncludeOptional sites-enabled/*.conf

显然/etc/apache2/sites-enabled下存放着有关虚拟站点（VirtualHost）的配置。经查看，初始情况下，该目录下包含一个符号链接：

000-default.conf -> ../sites-available/000-default.conf

这里又引出另外一个配置目录：/etcc/apache2/sites-available。这个目录下放置了所有可用站点的真正配置文件，对于Enabled的站点，Apache2在sites-enabled目录建立一个到sites-available目录下文件的符号链接。

/etc/apache2/sites-available下有两个文件：000-default.conf和default-ssl.conf。000-default链接的文件为000-default.conf。

以000-default.conf为例，看看一个VirtualHost的配置是啥样的：

<VirtualHost *:80>        #此处是访问的端口
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    #ServerName www.example.com        # 服务名，默认被注释，部署多站点时需要取消注释，重点修改项

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html        # 站点目录，重点修改项



    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # For most configuration files from conf-available/, which are
    # enabled or disabled at a global level, it is possible to
    # include a line for only one particular virtual host. For example the
    # following line enables the CGI configuration for this host only
    # after it has been globally disabled with "a2disconf".
    #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

DocumentRoot是这个站点的根目录，这样Apache2启动时会扫描/etc/apache2/sites-enabled中可用的站点配置并加载。当用户访问localhost:80时，Apache2就将default站点根目录/var/www/html下的index.html作为请求的响应返回给浏览器。

三、利用Apache2部署多个站点

建议不要修改Apache2的默认站点，通过新增站点配置来满足同时部署多站点的需求。需求大致可分为两类：

• 根据不同域名访问不同的站点
• 在相同域名地址的情况下，通过访问不同端口访问不同站点

3.1 第一种需求

目的：在一个Apache2服务器上根据不同域名site1.com和site2.com来访问不同的站点

步骤：

1. 建立配置文件

在sites-available中建立两个站点的配置文件site1_com和site2_com：

sudo cp 000-default.conf site1_com.conf
sudo cp 000-default.conf site2_com.conf

2. 编辑这两个配置文件，以site1_com为例

<VirtualHost *:80>        # 根据不同域名访问不同站点，无需修改端口
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    ServerName site1.com        # 需要取消注释，并修改服务名

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/site1_com        # 需要修改站点目录

    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # For most configuration files from conf-available/, which are
    # enabled or disabled at a global level, it is possible to
    # include a line for only one particular virtual host. For example the
    # following line enables the CGI configuration for this host only
    # after it has been globally disabled with "a2disconf".
    #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

注意上面配置中：ServerName、DocumentRoot是我们重点关注的配置点。site1的ServerName为site1.com，根目录为/var/www/site1_com。(site2_com.conf也做同样的改动)

3. 在sites-enabled目录下建立符号链接（！！！用绝对路径！！！）

sudo ln -s /etc/apache2/sites-available/site1_com.conf /etc/apache2/sites-enabled/site1_com.conf
sudo ln -s /etc/apache2/sites-available/site2_com.conf /etc/apache2/sites-enabled/site2_com.conf

4. 部署项目（以Angular2项目为例）

将站点移动到apache2的默认目录下
/var/www/

5. 重启Apache2使配置生效

sudo service apache2 restart
或
sudo /etc/init.d/apache2 restart

6. 测试

打开浏览器，输入http://site1.com ，即可看到我们的网站。

3.2 第二种需求

目的：同一个域名地址通过不同端口号访问虚拟站点（！！！需要在防火墙添加对应端口的规则！！！）

步骤：

1. 让Apache2监听端口8081和8082

修改/etc/apache2/ports.conf，增加两行：

Listen 8081
Listen 8082

2. 修改site1_com.conf和site2_com.conf：

以site2_com为例,将监听的端口改为8082，ServerName改为site.com。（site1_com同理。）

<VirtualHost *:8082>        # 需要修改端口号
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    ServerName site.com        # 需要取消注释，并修改服务名

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/site2_com        # 修改站点目录

    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # For most configuration files from conf-available/, which are
    # enabled or disabled at a global level, it is possible to
    # include a line for only one particular virtual host. For example the
    # following line enables the CGI configuration for this host only
    # after it has been globally disabled with "a2disconf".
    #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

3. 在sites-enabled目录下建立符号链接（！！！用绝对路径！！！）

sudo ln -s /etc/apache2/sites-available/site1_com.conf /etc/apache2/sites-enabled/site1_com.conf
sudo ln -s /etc/apache2/sites-available/site2_com.conf /etc/apache2/sites-enabled/site2_com.conf

4. 重启Apache2使配置生效

sudo service apache2 restart
或
sudo /etc/init.d/apache2 restart

5. 测试

访问 http://site.com:8082 即可看到我们的网站。