## Index → Configuration

## Virtual Server

Virtual Server is an abstraction mechanism that allows you to define a custom number of parameters and rules that have to be applied to one or more domains.

In a Cherokee server there must be at least one virtual server named default, and there is no maximum number. It is important to know that this server cannot be deleted.

When the server receives a request it will try to match the domain name specified in the virtual server that should handle it. In case no virtual server matches the request, default will be used.

Three main options are accessible through this menu:

1. Virtual Server List

2. Add new Virtual Server

3. Clone Virtual Server

Cloning a Virtual Server is simply a matter of selecting a target name and a source virtual server currently present. Every setting will be duplicated. From then onwards changes applied to any of them, be it the original or the copied Virtual Servers, will only apply to the implicated one. This is a great way to set up complex domains, since you can use the existing ones as templates to be refined with further work.

To add a new Virtual Server you have to enter the server name and a valid Document Root directory.

- Document Root

  This directive sets the directory from which Cherokee will serve files. The set of rules is checked from the highest to the lowest possible priority. Once a rule is matched, the server appends the path from the requested URL to the document root to make the path to the document. If it is a directory, this information is used. If other rules apply to a parent directory, those are applied as well without overwriting the original behavior:

              http://www.example.com/index.html refers to /var/www/index.html

  This might seem complicated but it's actually simple to understand. For example suppose you had a directory called /secret that was protected with authentication, and there was also a rule with higher priority for /secret/cgi that only specified to use the CGI handler. Under these circumstances, if a request was received for /secret/cgi/something then the CGI handler would be taken and it would inherit the authentication specified for /secret.

- Name

  Name is an alias. The domain names handled by the virtual server should be specified later in the virtual server details page.

The Virtual Server List is by far the most interesting of these three main options. It gives an overview of the existing virtual servers, and allows to configure in detail every possible setting.

A detailed explanation of every tab follows.

### Basics

- Directory Indexes

  The DirectoryIndex directive sets the list of resources to look for when the client requests an index of the directory by specifying a / at the end of the directory name. Several URLs may be given, in which case the server will return the first one that it finds. If none of the resources exist, the server will reply according to the handler behavior.

  Note that the documents do not need to be relative to the directory:

              index.html,index.txt,/cgi-bin/index.pl

  would cause the CGI script /cgi-bin/index.pl to be executed if neither index.html nor index.txt existed in a directory.

  There is a special case in which the directory index entry starts with a slash. For example, /cgi-bin/index.pl. In that case, it will use it as the object accessible under that public address of the same virtual server, so it will take care about the possible configuration of the /cgi-bin/ directory and/or the pl extension.

### Domain names

This section allows to define the list of domains that the virtual server implements.

It can accepted either FQDN (Fully Qualified Domain Names) or wild card entries.

For instance

                example.com
              *.example.org

### Behavior

This sections allows to define a set of rules to define how the server should handle the different requests. A summary of the existing rules is presented, containig several fields of information:

1. Target: web target of the rule, be it a path, a file type, etc.

2. Type: Rule type. The will be explained in the following paragraphs.

3. Handler: The handler that manages the requests that match this rule. Read on for further details.

4. Auth: Indicates if authentication is used for this rule. This can be set up through the Rule Entry menu.

5. Final: If this flag is present it means that no other rules will be applied after this one, even if the request also matches other rules with lower priority.

These rules can be defined based on the directory that the request targets, the extension of the file that it is requesting, or a regular expression that may match the request. This is the list of available rule types:

- Directory: The entry Directory encloses a group of directives which will apply only to the named directory and sub-directories of that directory.

- Extensions: The entry Extensions doesn't care about directories, it will just look for the extension of the object requested.

- Regular Expressions: The Request entry provides a powerful way to apply custom options to requests. It is a complement for the Directory and Extension entries. Basically, there are two differences between them:

  - It uses regular expressions to define the requests in which the configuration will be applied.

  - These entries are able to use the connection parameters (both pathinfo and query string). In this way it is possible to set rules based on parameter values.

- Header: This type of rule is used to modify the behavior in response to the contents of HTTP headers. A regular expression is needed to match against. This kind of rule can be used to provide alternative contents to a specific type of users. For example, it can check if the HTTP referrer header refferences specific domains to allow or deny the delivery of the requested information.

- GeoIP: If GeoIP support is present, this type of rules can be added. The GeoIP library has to be present at build time for this to happen. If enabled, specific behavior can be offered depending on the country of origin of the requests to the web server. Note that the country is determined by matching the IPs to the actual list of countries handled by the library, so the usage of proxies on the user side will render this resolution mechanism inaccurate. An initial country must be added to the rule, and more selections can be added in further steps.

It is very important to know that these rules are prioritized. The higher its priority is, the sooner they are checked. You could think of a network routing table, it is quite similar. You can set the relative priorities among the rules by simply dragging and dropping them in the desired position (if you click on the rule name, you will be redirected to the rule's configuration options; if you click anywhere else, you will be able to drag and drop it into the desired position).

Each of these behavior rules must specify which is the handler that the server should use to reply to the requests that match the rule. Handlers are the modules that generate the information with which the server responds a client's request. By default Cherokee provides a number of them:

- common - List & Send

  Combines both `Static Content` and `Only listing` handlers functionality to behave similarly to common web servers, it will display directory listings when a directory is requested and serve the requested files.

- Static Content - Static Content

  This is the file handler and it serves files straight from the file system.

- dirlist - Only listing:

  Displays a directory content list when a directory is requested, but it does not allow to download any content.

- redir - Redirection

  Perform simple and/or complex redirections using regexes.

- cgi - CGI Execution

  Executes CGI programs.

- fcgi - FastCGI Server Support

  Communicates with FastCGI servers.

- scgi - SCGI Server Support

  Communicates with SCGI servers.

- Server Info - Server Info

  Provide some configurable information about the server.

- Generic balancer - Generic balancer

  Select one of the available mechanisms to distribute the load (locally or remotely).

- Remote Administration - Remote Administration

  Implements an administration interface to work with cherokee-tweak.

The selection of any one of the rule targets will offer new configuration options through the Rule Entry menu.

Each of the mentioned handlers can be fine-tuned through that menu. Refer to each handler's documentation if you are interested in the available settings.

### Personal Webs

This options allows to setup the name of a subdirectory inside the users' home directory that will be used as document root for personal web content. For instance, if `/foo` was specified, a user `bar` could publish the content of /foo at the relative URL /bar This option is disabled if the Directory name field is empty.

### Error Handler

Several mechanisms exist to handle errors.

1. Default errors

2. Custom redirections

3. Closest match

Using the Custom redirections error handler we can easily redirect errors to a custom path or website.

The Closest match error handler should never fail to deliver something. If a requested resource is not available, the closest match will be sent. The only exception to this is when nothing at all is at Cherokee's disposal, in which case a standard http error is sent.

### Logging

The loggers are a type of Cherokee modules to write the server log information using different destinations and/or formats:

- Destination: File, syslog, program execution and standard error output.

- Format: Combined (Apache compatible), NCSA or W3C

If a virtual server doesn't have a logger set up it will not log anything.

By default Cherokee ships three loggers implementing three different logging formats:

- combined - Combined Log Format

  Logging using the Apache log format. It is the `de facto standard` nowadays.

- ncsa - NCSA Log Format

  Logging using the NCSA log format.

- w3c - W3C Log Format

  Logging using the W3C log format.

### Security

The virtual server must be configured with the path to the certificate before using secure connections (https). There is a document which might help to generate SSL keys