Setting up a subdomain with Apache on Linux

Question

I can't believe that I haven't done this before, but I would like a definitive answer so I'm all set going forward.

I have an apache config file at /etc/apache2/sites-available/mysite which looks like this:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost

    DocumentRoot /home/sam/public_html
    <Directory />
            Options FollowSymLinks
            AllowOverride All
    </Directory>
    <Directory /home/sam/public_html>
            Options Indexes FollowSymLinks MultiViews
            AllowOverride All
            Order allow,deny
            allow from all
    </Directory>

    ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
    <Directory "/usr/lib/cgi-bin">
            Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
            Order allow,deny
            Allow from all
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

So this serves html and php files from ~/public_html all fine. But I have multiple projects there so would like to start using subdomains. What I want to do is serve files from ~/public_html/myproject/ as the root directory for myproject.localhost.

I have tried adding the following to the bottom of my apache file:

<VirtualHost myproject.localhost>
    DocumentRoot ~/public_html/myproject/
    ServerName myproject.localhost
    ServerAdmin [email protected]
    <Directory ~/public_html/myproject>
            Options Indexes FollowSymLinks
            AllowOverride FileInfo
            Order allow,deny
            Allow from all
    </Directory>
</VirtualHost>

but apache complains:

Restarting web server: apache2[Tue Aug 20 11:06:19 2013] [error] (EAI 2)Name or service not known: Could not resolve host name myproject.localhost -- ignoring!
 ... waiting [Tue Aug 20 11:06:20 2013] [error] (EAI 2)Name or service not known: Could not resolve host name myproject.localhost -- ignoring!

I know I'm committing a fundamental error, but I'm not sure what it is.

Edit

This is my complete file now:

<VirtualHost *:80>
    DocumentRoot /home/sam/public_html/ryua1226-magento/
    ServerName mydomain.localhost
    ServerAdmin [email protected]
    <Directory /home/sam/public_html/ryua1226-magento>
            Options Indexes FollowSymLinks
            AllowOverride FileInfo
            Order allow,deny
            Allow from all
    </Directory>
</VirtualHost>


<VirtualHost *:80>
    ServerAdmin webmaster@localhost

    DocumentRoot /home/sam/public_html
    <Directory />
            Options FollowSymLinks
            AllowOverride All
    </Directory>
    <Directory /home/sam/public_html>
            Options Indexes FollowSymLinks MultiViews
            AllowOverride All
            Order allow,deny
            allow from all
    </Directory>

    ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
    <Directory "/usr/lib/cgi-bin">
            Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
            Order allow,deny
            Allow from all
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost> 

Answer 1

You are telling Apache what IP and port you want to answer it on inside of the <VirtualHost> tag so here * means any IP, but accept requests for this site on port 80. Next you need to tell Apache where the document root is. ~/ means your default home directory, so if your DocumentRoot just happens to be the default home variable then it would work with your existing notation (depending on which user you're running the server as). Then you would declare the server name.

Each domain name you're create a host for needs its own Virtual Host Directive unless you're using aliases.

<VirtualHost *:80>
    DocumentRoot /home/sam/public_html
    ServerName myproject.localhost

    # Other directives here

</VirtualHost>

<VirtualHost *:80>
    DocumentRoot /home/sam/public_html/myproject
    ServerName myotherproject.localhost

    # Other directives here

</VirtualHost>

About Hosts In addition to this, any special name that you create for a host needs to go into a hosts file or in the DNS server as well. This way any web browser that is looking for your server can find it without having to type in the IP. Since you'll likely have multiple hosts on the same IP with your setup if you were to try and access the server with the IP only, you would only get the first host to respond on the IP (usually the top in the vhosts list).