dev_cherokee.conf.txt

== link:index.html[Index] -> link:dev.html[Development info]
////
Outdated. Most changes since January 2009 are trivial, and not much
content has been added since.
////

Development: cherokee.conf
--------------------------

[[introduction]]
Introduction
~~~~~~~~~~~~

Cherokee's configuration system is based on an internal text file
format that the average user should not know about. This configuration
file is read by the server and modified by the administration
interface, so unless you are a Cherokee developer or a really
advanced user, the following format description will not be very
interesting to you.

The default location for Cherokee configuration files is
``/etc/cherokee``, but this may vary based on distribution or
installation parameters.

If you are completely sure about what you are doing, you can modify it
by hand. We recommend you not to do so, since everything can be
handled from link:other_bundle_cherokee-admin.html[cherokee-admin] and a lot
of security measures and consistency checks are made to ensure you end
up with a well formed `cherokee.conf` file.

Having said that, let's proceed to describe the configuration file format. It
is basically a text file that contains a tree where nodes
contain values.

Let's see a basic example::
+
----
    server!bind!1!port = 80
    server!keepalive = 1
----

Most of the modules and plug-ins read a piece of the tree to
configure themselves. It provides extremely flexible configuration
capabilities for the price of a fairly complex text file. However, I
would like to point out again that users should never read of modify the
configuration file by hand, so it is a format that only developers
should know about.

The following blocks will summarize the configuration keys that the
current Cherokee release handles:

[[server]]
Server
~~~~~~

The server configuration keys define some of the server-wide
properties, such as the user under which the server ought to run if it
is run as root or whether to use keep-alive connections.

[options="header"]
|====================================================================
|**Key**                       |**Type** |**Description**
|server!bind!#!port            |Number   |Listen to a TCP port. '#' is a sequential number since many ports can be listened at once.
|server!bind!#!tls             |Bool    |on\|off: whether the listened port '#' is for HTTPS.
|server!max_fds                |Number   |Max open file descriptors
|server!listen_queue           |Number   |Length of the listen queue
|server!thread_number          |Number   |Number of threads
|server!sendfile_min           |Number   |Minimum file size of using sendfile
|server!sendfile_max           |Number   |Maximum file size of using sendfile
|server!max_connection_reuse   |Number   |How many connections to reuse
|server!ipv6                   |Bool     |Whether to use IPv6
|server!timeout                |Number   |Connections timeout
|server!log_flush_lapse        |Number   |Time between log flushes
|server!nonces_cleanup_lapse   |Number   |Time between Nonces clean ups
|server!keepalive              |Bool     |Allow keepalive connections
|server!keepalive_max_requests |Number   |How many keepalive reqs per connection
|server!unix_socket            |Path     |Listen to a Unix socket
|server!panic_action           |Path     |Path to cherokee-panic
|server!chroot                 |Bool     |Whether to use chroot
|server!pid_file               |Path     |PID file
|server!listen                 |IP       |Listen NIC
|server!poll_method            |String   |Which poll method it should use
|server!server_tokens          |String   |"Server identification: minor, minimal, os, full"
|server!thread_policy          |String   |"Thread policy: fifo, rr, other"
|server!user                   |String/Number |Change effective user
|server!group                  |String/Number |Change effective group
|server!module_dir             |Path     |Path to the plug-in directory
|server!module_deps            |Path     |Path to the plug-in inter-dependencies files
|====================================================================

``server!server_tokens`` parameters

[cols="20%,80%",options="header"]
|=====================================
|Value   |Description
|Product |Cherokee
|Minor   |Cherokee/1.0
|Minimal |Cherokee/1.0.0
|OS      |Cherokee/1.0.0 (UNIX)
|Full    |Cherokee/1.0.00 b5077 (UNIX)
|=====================================

``server!thread_policy`` parameters

[cols="20%,80%",options="header"]
|=====================================
|Value   |Description
|fifo    |First in first out
|rr      |Round Robin
|other   |By default in Linux
|=====================================


[[virtual_server]]
Virtual Server
~~~~~~~~~~~~~~

A virtual server contains the information related to one or more
domains under the same configuration. In a Cherokee server there must
be at least one virtual server named ``default``, and there is no
maximum number.

The prefix of this type of entry is ``vserver``, and by far, it is the
most common type of entry.

Virtual servers are stored in a numbered list. The starting number
does not really matter. What matters is that the list will be
interpreted in an orderly fashion to prioritize some virtual servers
over others, which can be of use depending on the way these are
defined. The only precaution to take is making sure there are no
repeated priorities, since the behavior in these cases in undefined.



[cols="40%,10%,50%",options="header"]
|===================================================================
|**Key**                            |**Type** |**Description**
|vserver!1!nick = default           |String   |The name of the Virtual Server
|vserver!1!document_root            |Path     |Document Root path
|vserver!1!user_dir                 |String   |Users' web directory (for ~ requests)
|vserver!1!domain! ``id``           |String   |"Domain name, admits wildcards"
|vserver!1!error_handler            |String   |Defines the error handler module
|vserver!1!directory_index          |List     |String list: Directory indexes
|vserver!1!ssl_certificate_file     |Path     |TLS/SSL certificate file
|vserver!1!ssl_certificate_key_file |Path     |TLS/SSL certificate key file
|vserver!1!ssl_ca_list_file         |Path     |TLS/SSL CA list file
|===================================================================

Besides these configuration keys there are a few other more complex
that needs further explanation:


Defining a virtual server behavior
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A virtual server behavior is basically defined by a rule list, which
includes a number of rules against which each request will be checked.

There are a number of rules types, each one checking a different
aspect of the request. The most usual rule types are the ones that
checks the request URI: directories, extensions, regular expressions
and headers.

All the rule types accept the same configuration sub-properties.
However, the ``match`` property must be present in all the cases. It
specifies which is the rule type and its properties.

The general syntax is::
+
`vserver ! order ! rule ! priority ! match`

The rule types plug-ins shipped within a standard Cherokee release
include:

*Directory*::
The directory specifies how to handle its contents.
+
Example: an entry with priority 20, setting the properties for the
*icons* directory of the default virtual host would be represented
by:
+
----
      vserver!1!nick = default
      vserver!1!rule!20!match!type = directory
      vserver!1!rule!20!match!directory = /icons
----

*Extension*::
It specifies a list of extensions and how they should be handled.
+
Eg: the JPG extensions is:
+
----
      vserver!1!rule!30!match!type = extensions
      vserver!1!rule!30!match!extensions = jpg,jpeg
----

*Requests*::
When a request matches a regular expression entry, it uses its configuration.
+
Eg: requests beginning with 'a' and PHP extension:
+
-----
      vserver!1!rule!40!match!type = request
      vserver!1!rule!40!match!request = ^a.*\.php$
----

*Header*::
It tries to match a regular expression against a certain header
entry.
+
Eg: check whether the Referer header matches a specific host:
+
----
      vserver!1!rule!50!match!type = header
      vserver!1!rule!50!match!header = Referer
      vserver!1!rule!50!match!match = .+\.example\.com
----

*Default*::
This rules matches every request. There must be a default rule
configured at the end of the rule list to handle the requests that
did not match any other rule. The end of the list means the smallest
priority value in relative terms. It doesn't have to be `1`
necessarily.
+
Eg: Default rule for the 'default' virtual server:
+
----
      vserver!1!rule!1!match = default
      vserver!1!rule!1!handler = common
      vserver!1!rule!1!handler!iocache = 0
----
+
The ``!encoder`` configuration entry allows to configure encoding
plug-ins. Each entry applies to a specific rule.

[cols="20%,80%",options="header"]
|=============================================================
|Parameter |Description
|deflate   |deflate encoder. 0\|1 to define disabled\|enabled.
|gzip      |zip encoder. 0\|1 to define disabled\|enabled.
|=============================================================

Example::
+
----
   vserver!1!rule!100!encoder!deflate = 1
   vserver!1!rule!100!encoder!gzip = 1
   vserver!1!rule!100!match = extensions
   vserver!1!rule!100!match!extensions = html
----
+
The following parameters are concatenated with any of the previous
kinds of entry:

[cols="20%,10%,70%",options="header"]
|===================================================================
|**Key**        |**Type** |**Description**
|priority       |Number   |Priority in the rules list
|directory_root |Path     |Special Directory Root for the request
|allow_from     |List     |List of IP/Domain allowed to access the resource
|handler        |String   |Handler (module) that handles the request
|auth           |String   |Validator (module) that protects the resource
|only_secure    |Bool     |Allow only secure (https) connections
|===================================================================

The ``auth`` entry deserves a little more attention,
actually. Accepted validator modules are `htdigest, htpasswd, ldap,
mysql, pam, plain`. It restricts the access to some of the objects
accessed by the web server based on a number of properties that are
defined at its child properties:

[cols="10%,10%,80%",options="header"]
|============================================================
|**Key**          |**Type** |**Description**
|auth!methods     |List     |Allowed methods (basic & digest)
|auth!realm       |String   |Realm of the resource
|auth!users       |List     |List of allowed users
|============================================================

Some validators have extra configuration keys.

.htdigest, htpasswd, plain
[cols="20%,10%,70%",options="header"]
|====================================================================
|**Key**         |**Type** |**Description**
|auth!passwdfile |String   |Full path to the passwords' file. htdigest\|htpasswd\|plain
|====================================================================

.mysql
[cols="20%,10%,70%",options="header"]
|====================================================================
|**Key**       |**Type** |**Description**
|auth!host     |String   |MySQL host.
|auth!database |String   |Database name.
|auth!user     |String   |Database user.
|auth!passwd   |String   |Database password.
|auth!port     |Number   |Port number of the service.
|auth!query    |String   |SQL query to match users/passwords. Replace your username for '${user}'.
|auth!use_md5_passwd |Bool |Encrypt the passwords with MD5.
|===================================================================

.ldap
[cols="20%,10%,70%",options="header"]
|====================================================================
|**Key**      |**Type** |**Description**
|auth!server  |String   |IP or hostname of the LDAP server.
|auth!port    |Number   |Port number of the service.
|auth!base_dn |String   |Base distinguished name.
|auth!bind_dn |String   |User
|auth!bind_pw |String   |Password
|auth!filter  |String   |LDAP search filter.
|auth!tls     |Bool     |Indicates TLS based integrity
|auth!ca_file |String   |Cert file. Must be provided if TLS is enabled.
|====================================================================

.authlist
[cols="20%,10%,70%",options="header"]
|====================================================================
|**Key**              |**Type** |**Description**
|auth                 |String   |name of the validator module: authlist
|auth!list!#!password |String   |Password for entry number #
|auth!list!#!user     |String   |User for entry number #
|====================================================================

[[examples]]
Here are a few examples about how this notation works:

- The default virtual server uses the "common" handler as default
  choice for its root directory:
+
----
    vserver!1!nick = default
    vserver!1!rule!10!directory!/!handler = common
----

- The \*.example.com and \*.examples.org domains are restricted to be
  accessed from the local loop interface, and have to be handled as a
  FastCGI:
+
----
    vserver!5!nick = example
    vserver!5!domains!1 = *.example.com
    vserver!5!domains!2 = *.example.org
    vserver!5!rule!10!directory!/!handler = fcgi
    vserver!5!rule!10!directory!/!priority = 1
    vserver!5!rule!10!directory!/!allow_from = 127.0.0.1,::1
----

- Rules can be defined that return custom errors using the
  link:modules_handlers_custom_error.html[HTTP error] handler: `custom
  error`.
+
----
    vserver!10!rule!100!handler = custom_error
    vserver!10!rule!100!handler!error = 400
----

- ISO images should be handled as files and are protected by a
  htdigest file using only Digest authentication:
+
----
    vserver!1!nick = default
    vserver!1!rule!100!extensions!iso,ISO!handler = file
    vserver!1!rule!100!extensions!iso,ISO!auth = htdigest
    vserver!1!rule!100!extensions!iso,ISO!auth!realm = My secret isos
    vserver!1!rule!100!extensions!iso,ISO!auth!methods = digest
    vserver!1!rule!100!extensions!iso,ISO!auth!passwdfile = /var/passwd/isos.htdigest
----

- Authenticated directory with `htpasswd` validator:
+
----
vserver!10!rule!500!auth = htpasswd
vserver!10!rule!500!auth!methods = basic
vserver!10!rule!500!auth!passwdfile = /var/www/passwd.htpasswd
vserver!10!rule!500!auth!realm = secret
vserver!10!rule!500!match = directory
vserver!10!rule!500!match!directory = /auth
vserver!10!rule!500!match!final = 0
vserver!10!rule!500!only_secure = 0
----

- Same example, using `mysql` validator:
+
----
vserver!10!rule!500!auth = mysql
vserver!10!rule!500!auth!database = auth_users
vserver!10!rule!500!auth!host = localhost
vserver!10!rule!500!auth!methods = basic,digest
vserver!10!rule!500!auth!passwd = db_passwd
vserver!10!rule!500!auth!port = 3306
vserver!10!rule!500!auth!query = SELECT password FROM auth_users WHERE username= '${user}'
vserver!10!rule!500!auth!realm = secret
vserver!10!rule!500!auth!use_md5_passwd = 1
vserver!10!rule!500!auth!user = db_user
vserver!10!rule!500!match = directory
vserver!10!rule!500!match!directory = /auth
vserver!10!rule!500!match!final = 0
vserver!10!rule!500!only_secure = 0
----

- Same thing with `ldap` validator:
+
----
vserver!10!rule!500!auth = ldap
vserver!10!rule!500!auth!base_dn = Example DN
vserver!10!rule!500!auth!bind_dn = Directory Manager
vserver!10!rule!500!auth!bind_pw = secretpassword
vserver!10!rule!500!auth!methods = basic
vserver!10!rule!500!auth!port = 389
vserver!10!rule!500!auth!realm = secret
vserver!10!rule!500!auth!server = ldap.example.com
vserver!10!rule!500!auth!tls = 0
vserver!10!rule!500!match = directory
vserver!10!rule!500!match!directory = /auth
vserver!10!rule!500!match!final = 0
vserver!10!rule!500!only_secure = 0
----

[[logs]]
Logs
~~~~

The log files are defined as properties inside the Virtual Server
hierarchy under a ``logger`` entry with the following properties:

[cols="20%,10%,70%",options="header"]
|========================================================
|**Key**        |**Type** |**Description**
|logger         |String   |Output format (validator name)
|logger!access  |Node     |Defines the access log file
|logger!error   |Node     |Defines the error log file
|========================================================

and then, both access and error accept a number of parameters
depending on its property ``type`` which specifies where the logging
information will be written. It can be either:

[options="header"]
|========================================================
|**Logger writer Type** |**Description**
|file                   |Write a file
|syslog                 |Use the system logging mechanism
|stderr                 |Use the standard output
|exec                   |Execute a program with each line
|========================================================

If either ``file`` or ``exec`` is used, there is an additional
parameter that has to be set. In the case of file, a sub-property
named ``filename`` and for exec ``command``.

Examples:

- Apache format logs to the regular files:
+
----
    vserver!1!nick = default
    vserver!1!logger = combined
    vserver!1!logger!access!type = file
    vserver!1!logger!access!filename = /var/log/cherokee.access.log
    vserver!1!logger!error!type = file
    vserver!1!logger!error!filename = /var/log/cherokee.error.log
----


[[information_sources]]
Information sources
~~~~~~~~~~~~~~~~~~~

They follow the format: ``source ! {source number} ! {key}``

[cols="20%,20%,60%",options="header"]
|===========================================================
|**Key**      |**Type** |**Description**
|nick         |String   |Alias to identify the source
|env          |String   |Variable to be set in the environment
|host         |String   |host:port or path to unix socket
|interpreter  |String   |command to launch the service if any
|type         |Type     |`host` \| `interpreter`
|timeout      |Number   |spawning timeout specified in seconds
|=============================================================

Examples:

- PHP configured for FastCGI through Unix socket
+
----
source!1!env!PHP_FCGI_CHILDREN = 5
source!1!host = /tmp/cherokee-php.sock
source!1!interpreter = /usr/bin/php-cgi -b /tmp/cherokee-php.sock
source!1!nick = php
source!1!type = interpreter
----

- Or via `host:port` as remote host:
+
----
source!1!host = localhost:1234
source!1!interpreter = /usr/bin/php-cgi -b /tmp/cherokee-php.sock
source!1!type = host
----

[[balancers]]
Balancers
~~~~~~~~~
The balancers must define the information sources to be used. For the
ones defined in the examples above, using round robin from within the
FastCGI handler, the following example would apply.

Example::
+
----
vserver!10!rule!600!handler = fcgi
vserver!10!rule!600!handler!balancer = round_robin
vserver!10!rule!600!handler!balancer!source!1 = 1
vserver!10!rule!600!match = extensions
vserver!10!rule!600!match!extensions = php
vserver!10!rule!600!match!final = 1
----

[[inclusion]]
Inclusion of Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~

Sometimes it is nice to break out your configuration into several logical files
to be more modular as well as more organized.  You can use the ``include``
configuration to accomplish this.

Here is an example::
+
----
    include = /etc/cherokee/advanced.conf
----

or even, it is possible to specify a directory to include all of its files::
+
----
    include = /etc/cherokee/mods-enabled/
----

[[reverse_proxy]]
Reverse Proxy
~~~~~~~~~~~~~

The reverse proxy , like everything in Cherokee, is modular. It is
configured as any other of the modules that use load balancers.

You need to define a balancing strategy, the information source to be
used by the balancer and, optionally, any expression matches that you
might wish to rewrite in the headers before relaying the connection.

This is a basic example:

----
server!bind!1!port = 1234

# The proxy configuration
vserver!1!nick = default
vserver!1!document_root = /tmp
vserver!1!rule!1!match = default
vserver!1!rule!1!handler = proxy
vserver!1!rule!1!handler!header_hide!1 = server
vserver!1!rule!1!handler!balancer = round_robin
vserver!1!rule!1!handler!balancer!source!1 = 1

# URL rewrite
vserver!1!rule!1!handler!rewrite_request!1!regex = ^/(.+).png$
vserver!1!rule!1!handler!rewrite_request!1!substring = /$1.jpg
vserver!1!rule!1!handler!rewrite_request!2!regex = ^/test/(.+)$ /$1.jpg
vserver!1!rule!1!handler!rewrite_request!2!substring = /test.php?$1

# The information source
source!1!type = host
source!1!host = localhost:9090
----