Configure Apache httpd to map subdomains to subdirectories

Question

I'm creating several subdomains and every time I need to create an Apache configuration file for every single subdomain. Is it possible to configure Apache httpd with a single configuration so that each sub-folder corresponds to a subdomain? Like

subdomain1.example.com -> /var/www/example.com/subdomain1/
subdomain2.example.com -> /var/www/example.com/subdomain2/
whatever.example.com -> /var/www/example.com/whatever/

In other words whenever I create a new folder my domain name will have a new subdomain.

question from:https://stackoverflow.com/questions/65932038/configure-apache-httpd-to-map-subdomains-to-subdirectories

Answer 1

A virtual host is defined by two pieces of information: its IP address, and the contents of the Host: header in the HTTP request. The dynamic mass virtual hosting technique is based on automatically inserting this information into the pathname of the file that is used to satisfy the request. This is done most easily using mod_vhost_alias, but if you are using a version of Apache up to 1.3.6 then you must use mod_rewrite. Both of these modules are disabled by default; you must enable one of them when configuring and building Apache if you want to use this technique.

A couple of things need to be `faked' to make the dynamic virtual host look like a normal one. The most important is the server name which is used by Apache to generate self-referential URLs, etc. It is configured with the ServerName directive, and it is available to CGIs via the SERVER_NAME environment variable. The actual value used at run time is controlled by the UseCanonicalName setting. With UseCanonicalName Off the server name comes from the contents of the Host: header in the request. With UseCanonicalName DNS it comes from a reverse DNS lookup of the virtual host's IP address. The former setting is used for name-based dynamic virtual hosting, and the latter is used for IP-based hosting. If Apache cannot work out the server name because there is no Host: header or the DNS lookup fails then the value configured with ServerName is used instead.

The other thing to `fake' is the document root (configured with DocumentRoot and available to CGIs via the DOCUMENT_ROOT environment variable). In a normal configuration this setting is used by the core module when mapping URIs to filenames, but when the server is configured to do dynamic virtual hosting that job is taken over by another module (either mod_vhost_alias or mod_rewrite) which has a different way of doing the mapping. Neither of these modules is responsible for setting the DOCUMENT_ROOT environment variable so if any CGIs or SSI documents make use of it they will get a misleading value.

Try:

# get the server name from the Host: header
UseCanonicalName Off

# this log format can be split per-virtual-host based on the first field
LogFormat "%V %h %l %u %t "%r" %s %b" vcommon
CustomLog logs/access_log vcommon

# include the server name in the filenames used to satisfy requests
VirtualDocumentRoot /path/to/default/folder/%0
VirtualScriptAlias /www/hosts/%0

See http://httpd.apache.org/docs/2.2/en/vhosts/mass.html