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.TH YAWS.CONF "5" "" "" "User Commands" -*- nroff -*-
.SH NAME
/etc/yaws/yaws.conf \- Configuration file for the Yaws web server
.SH DESCRIPTION
.\" Add any additional description here
.PP
Yaws is fast lightweight web server. It reads a configuration file called
yaws.conf to control its operations. The configuration contains two distinct
parts: a global part which affects all the virtual hosts and a server part where
options for each virtual host is supplied.
.SH GLOBAL PART
.TP
\fBlogdir = [+]Directory\fR
All Yaws logs will be written to files in this directory. If specified with
\fB+\fR, Yaws will attempt to create the directory if it does not exist. There
are several different log files written by Yaws:
\fBreport.log\fR - this is a text file that contains all error logger printouts
from Yaws.
\fB<Host>.access\fR - for each virtual host served by Yaws, a file <Host>.access
will be written that contains an access log in NCSA combined/XLF/ELF log format. (See
http://www.w3.org/TR/WD-logfile.html for more details on Extended Log File
Format.)
\fB<Host>.auth\fR - for each virtual host served by Yaws, a file <Host>.auth
will be written which contains all http auth related messages.
\fBtrace_<YYYYMMDD_hhmmss>\fR - Trace files are written in this subdirectory,
suffixed by the creation date.
.RS 12
\fBtrace.<Pid>.http\fR - this file contains the HTTP trace if that is enabled,
where <Pid> is the process id handling the TCP connection.
\fBtrace.<Pid>.traffic\fR - this file contains the traffic trace if that is
enabled, where <Pid> is the process id handling the TCP connection.
.RE
.IP
Note that <Host>.access and <Host>.auth files will be used only if the directive
\fBlogger_mod\fR is not set or set to yaws_log. The default value for logdir is
\fI"."\fR
.TP
\fBebin_dir = Directory\fR
This directive adds Directory to the Erlang search path. It is possible to have
several of these commands in the configuration file. The default value is
\fI"yaws_dir"/examples/ebin\fR
.TP
\fBsrc_dir = Directory\fR
This directive defines a Directory as a \fIsource\fR directory. Yaws will
compile all erlang modules found in this directory and all its
subdirectories. The compilation occurs when the configuration is loaded or
reloaded. The \fBinclude_dir\fR directives are used to search for includes
files. Multiple \fBsrc_dir\fR directives may be used. There is no such directory
configured by default.
.TP
\fBid = String\fR
It is possible to run multiple Yaws servers on the same machine. We use the id of a
Yaws server to control it using the different control commands such as:
.nf
# /usr/local/bin/yaws --id foobar --stop
.fi
To stop the Yaws server with id "foobar". Each Yaws server will write its
internal data into a file called $HOME/.yaws/yaws/ID where ID is the identity
of the server. Yaws also creates a file called $HOME/.yaws/yaws/ID/CTL
which contains the port number where the server is listening for control
commands. The default id is \fI"default"\fR.
.TP
\fBserver_signature = String\fR
This directive sets the "Server: " output header to the custom value. The
default value is \fI"yaws/%VSN%, Yet Another Web Server"\fR.
.TP
\fBinclude_dir = Directory\fR
This directive adds Directory to the path of directories where the Erlang
compiler searches for include files. We need to use this if we want to
include .hrl files in our Yaws Erlang code. It is possible to have several of
these commands in the configuration file. The default value is
\fI"yaws_dir"/examples/include\fR.
.TP
\fBmax_num_cached_files = Integer\fR
Yaws will cache small files such as commonly accessed GIF images in RAM. This
directive sets a maximum number on the number of cached files. The default
value is \fI400\fR.
.TP
\fBmax_num_cached_bytes = Integer\fR
This directive controls the total amount of RAM which can maximally be used for
cached RAM files. The default value is \fI1000000\fR, 1 megabyte.
.TP
\fBmax_size_cached_file = Integer\fR
This directive sets a maximum size on the files that are RAM cached by Yaws.
The default value is \fI8000\fR, 8 kBytes.
.TP
\fBcache_refresh_secs = Integer\fR
The RAM cache is used to serve pages that sit in the cache. An entry sits in
cache at most cache_refresh_secs number of seconds. The default is
\fI30\fR. This means that when the content is updated under the docroot, that
change doesn't show until 30 seconds have passed. While developing a Yaws site,
it may be convenient to set this value to 0. If the debug flag (-d) is passed to
the Yaws start script, this value is automatically set to 0.
.TP
\fBtrace = false | traffic | http\fR
This enables traffic or http tracing. Tracing is also possible to enable with a
command line flag to Yaws. Default is \fIfalse\fR.
.TP
\fBauth_log = true | false\fR
\fBDeprecated and ignored. Now, this target must be set in server part.\fR
.TP
\fBmax_connections = nolimit | Integer\fR
Set this value to control the maximum number of connections from HTTP clients
into the server. This is implemented by closing the last socket if the limit
threshold is reached.
.TP
\fBkeepalive_maxuses = nolimit | Integer\fR
Normally, Yaws does not restrict the number of times a connection is kept alive
using keepalive. Setting this parameter to an integer X will ensure that
connections are closed once they have been used X times. This can be a useful
to guard against long running connections collecting too much garbage in the
Erlang VM.
.TP
\fBprocess_options = undefined | Proplist\fR
Set process spawn options for client acceptor processes. Options must be
specified as a quoted string of either the atom \fIundefined\fR or as a proplist
of valid process options. The supported options are \fIfullsweep_after\fR,
\fImin_heap_size\fR, and \fImin_bin_vheap_size\fR, each taking an associated
integer value. Other process options are ignored. The proplist may also be
empty. See \fBerlang:spawn_opt/4\fR for details on these options.
.TP
\fBlarge_file_chunk_size = Integer\fR
Set the chunk size used by Yaws to send large files when sendfile is not
supported or disabled. The default value is \fI10240\fR.
.TP
\fBlarge_file_sendfile = erlang | yaws | disable\fR
Set the version of sendfile method to use to send large files (if supported):
\fBerlang\fR - use \fIfile:sendfile/5\fR, if supported.
\fByaws\fR - use Yaws sendfile linked-in driver, if supported.
\fBdisable\fR - do not use any sendfile method, but \fIgen_tcp:send/2\fR.
The default value is \fIyaws\fR.
.TP
\fBacceptor_pool_size = Integer\fR
Set the size of the pool of cached acceptor processes. The specified value must
be greater than or equal to 0. The default value is \fI8\fR. Specifying a value
of 0 effectively disables the process pool.
.TP
\fBlog_wrap_size = Integer\fR
The logs written by Yaws are all wrap logs, the default value at the size where
they wrap around and the original gets renamed to File.old is \fI1000000\fR, 1
megabyte. This value can be changed.
.br
If we set the value to 0 the logs will never wrap. If we want to use Yaws in
combination with a more traditional log wrapper such as logrotate, set the size
to 0 and Yaws will reopen the logfiles once they have be renamed/removed.
.TP
\fBlog_resolve_hostname = true | false\fR
By default the client host IP is not resolved in the access logs.
.TP
\fBfail_on_bind_err = true | false\fR
Fail completely or not if Yaws fails to bind a listen socket Default is
\fItrue\fR.
.TP
\fBenable_soap = true | false\fR
If true, a soap server will be started at startup of Yaws. Default is
\fIfalse\fR.
.TP
\fBsoap_srv_mods = ListOfModuleSetting\fR
If enable_soap is true, a startup Yaws will invoke \fIyaws_soap_srv:setup()\fR
to setup modules set here. ModuleSetting is either a triad like \fI<Mod,
HandlerFunc, WsdlFile>\fR or a quadruple form like \fI<Mod, HandlerFunc,
WsdlFile, Prefix>\fR which specifies the \fIprefix\fR. A \fIprefix\fR will be
used as argument of \fIyaws_soap_lib:initModel()\fR and then be used as a XML
namespace prefix. Note, the \fIWsdlFile\fR here should be an absolute-path file
in local file systems.
For example, we can specify
.nf
soap_srv_mods=<Mod1, Handler, Wsdl1> <Mod2, Handler, Wsdl2, Prefix> ...
.fi
.TP
\fBphp_exe_path = Path\fR
\fBthis target is deprecated and useless. use 'php_handler' target in server
part instead.\fR
.br
The name of (and possibly path to) the php executable used to interpret php
scripts (if allowed). Default is \fIphp_exe_path = php-cgi\fR.
.TP
\fBcopy_error_log = true | false\fR
Enable or disable copying of the error log. When we run in embedded mode, there
may very well be some other systems process that is responsible for writing the
errorlog to a file whereas when we run in normal standalone mode, we typically
want the Erlang errorlog written to a report.log file. Default value is
\fItrue\fR.
.TP
\fBysession_mod = Module\fR
Allows to specify a different Yaws session storage mechanism instead of an ETS
table. One of the drawbacks of the default yaws_session_server implementation is
that server side cookies are lost when the server restarts. Specifying a
different module here will pass all write/read operations to this module (it
must implement appropriate callbacks).
.TP
\fBysession_idle_timeout = Integer\fR
Controls Yaws session idle cleanup. If a server has been idle for
\fIysession_idle_timeout\fR milliseconds, check all Yaws sessions and
remove any that have timed out. The default \fIysession_idle_timeout\fR
value is 2*60*1000 (2 minutes).
.TP
\fBysession_long_timeout = Integer\fR
Controls Yaws session periodic cleanup. Every \fIysession_long_timeout\fR
milliseconds, check all Yaws sessions and remove any that have timed
out. The default \fIysession_long_timeout\fR value is 60*60*1000 (1 hour).
.TP
\fBrunmod = ModuleName\fR
At startup Yaws will invoke \fIModuleName:start()\fR in a separate process. It
is possible to have several runmods. This is useful if we want to reuse the
Yaws startup shell script for our own application.
.TP
\fBpick_first_virthost_on_nomatch = true | false\fR
When Yaws gets a request, it extracts the Host header from the client
request to choose a virtual server amongst all servers with the same
IP/Port pair. This configuration parameter decides whether Yaws should
pick the first server (as defined in the yaws.conf file) if no name match
or not. If this is false and no Host header is present in the request, Yaws
returns a 400 Bad Request as required by the HTTP standard. In real live
hosting scenarios we typically want this to be false, whereas in
testing/development scenarios it may be convenient to set it to
true. Default is \fItrue\fR.
.TP
\fBkeepalive_timeout = TimeInMilliseconds | infinity\fR
If the HTTP session will be kept alive (i.e., not immediately closed) it will
close after keepalive_timeout milliseconds unless a new request is received in
that time. The default value is \fI30000\fR. The value \fIinfinity\fR is legal
but not recommended.
.TP
\fBsubconfig = File\fR
Load specified config file. Absolute paths or relative ones to the configuration
location are allowed. Unix-style wildcard strings can be used to include several
files at once. See \fIfilelib:wildcard/1\fR for details. Hidden files, starting
by a dot, will be ignored. For example:
.nf
subconfig = /etc/yaws/global.conf
subconfig = /etc/yaws/vhosts/*.conf
.fi
Or, relatively to the configuration location:
.nf
subconfig = global.conf
subconfig = vhosts/*.conf
.fi
.TP
\fBsubconfigdir = Directory\fR
Load all config files found in the specified directory. The given Directory can
be an absolute path or relative to the configuration location. Hidden files,
starting by a dot, will be ignored.
.TP
\fBx_forwarded_for_log_proxy_whitelist = ListOfUpstreamProxyServerIps\fR
\fBthis target is deprecated and will be ignored.\fR
.TP
\fBdefault_type = MimeType\fR
Defines the default MIME type to be used where Yaws cannot determine it by its
MIME types mappings. Default is \fItext/plain\fR.
.TP
\fBdefault_charset = Charset\fR
Defines the default charset to be added when a response content-type is
\fItext/*\fR. By default, no charset is added.
.TP
\fBmime_types_file = File\fR
Overrides the default \fImime.types\fR file included with Yaws. This file must
use the following format:
.nf
# Lines beginning with a '#' or a whitespace are ignored
# blank lines are also ignored
<MIME type> <space separated file extensions>
.fi
The default file is located at \fI${PREFIX}/lib/yaws/priv/mime.types\fR. You
should not edit this file because it may be replaced when you upgrade your
server.
.TP
\fBadd_types = ListOfTypes\fR
Specifies one or more mappings between MIME types and file extensions. More than
one extension can be assigned to a MIME type. \fIListOfTypes\fR is defined as
follows:
.nf
add_types = <MimeType1, Ext> <MimeType2, Ext1 Ext2 ...> ...
.fi
The mappings defined using this directive will overload all other
definitions. If a file extension is defined several times, only the last one is
kept. Multiple \fBadd_types\fR directives may be used.
.TP
\fBadd_charsets = ListOfCharsets\fR
Specifies one or more mappings between charsets and file extensions. More than
one extension can be assigned to a charset. \fIListOfCharsets\fR is defined as
follows:
.nf
add_charsets = <Charset1, Ext> <Charset2, Ext1 Ext2 ...> ...
.fi
The mappings defined using this directive will overload all other
definitions. If a file extension is defined several times, only the last one is
kept. Multiple \fBadd_charsets\fR directives may be used.
.TP
\fBsni = disable | enable | strict\fR
Enables or disables the TLS SNI (Server Name Indication) support.
When disabled (or not supported), all virtual servers in the same group (same
IP/Port) must share the same SSL configuration, especially the same SSL
certificate. Only the HTTP Host header will be considered to find the right
virtual server.
When enabled, SSL configuration can be different from a virtual server to
another, each one can have its own SSL certificate. In this case, if a client
provides a SNI hostname, it will be used to find the right virtual server. To
accept the SNI information from the client, The first virtual server (the
default one, see \fBpick_first_virthost_on_nomatch\fR) \fBmust\fR include TLS as
a permitted protocol.
If \fBsni\fR directive is set to \fIenable\fR, non SNI clients are allowed. For
such clients, virtual servers are selected as if Yaws did not have SNI
support. If it is set to \fIstrict\fR, SNI hostname is mandatary to access a SSL
virtual server. But, in all cases, when SNI support is enabled, if a client
provides a SNI hostname, it \fBmust\fR match the HTTP Host header (which is
mandatory too). Note that the first virtual server (the default one) will be
used for any request where the provided SNI hostname doesn't match any of
virtual server names. So, it is important that the first virtual server have the
most restrictive access control, otherwise clients can access restricted
resources by sending a request for any unknown hostname. (This isn't actually
any different from using virtual servers without SNI support.)
The \fBsni\fR directive is a global one, so if you set it to \fIstrict\fR, non
SNI clients will be refused for \fBall\fR SSL groups. See \fBrequire_sni\fR
directive from the server part to mitigate this requirement.
Default is \fIdisable\fR.
\fBWARNING: The SNI support was introduced in the SSL application in Erlang/OTP
18.0, so Yaws ignores it for previous releases.\fR
.SH SERVER PART
Yaws can virthost several web servers on the same IP address as well as several
web servers on different IP addresses. This includes SSL servers.
.PP
Each virtual host is defined within a matching pair of \fB<server ServerName>\fR
and \fB</server>\fR. The ServerName will be the name of the webserver.
.PP
The following directives are allowed inside a server definition.
.TP
\fBport = Port\fR
This makes the server listen on Port. Default is \fI8000\fR.
.TP
\fBlisten = IpAddress\fR
This makes the server listen on IpAddress. When virthosting several servers on
the same ip/port address, if the browser doesn't send a Host: field, Yaws will
pick the \fIfirst\fR server specified in the config file. If the specified IP
address is 0.0.0.0 Yaws will listen on all local IP addresses on the specified
port. Default is \fI127.0.0.1\fR. Multiple \fBlisten\fR directives may be used to
specify several addresses to listen on.
.TP
\fBlisten_backlog = Integer\fR
This sets the TCP listen backlog for the server to define the maximum length the
queue of pending connections may grow to. The default is 1024.
.TP
\fB<listen_opts> ... </listen_opts>\fR
Defines extra options to be set on the listen socket and, by inheritance, on
accepted sockets. See \fIinet:setopts/2\fR for details. Supported options are:
\fBbuffer = Integer\fR (default: same as \fIinet:setopts/2\fR)
\fBdelay_send = true | false \fR (default: same as \fIinet:setopts/2\fR)
\fBlinger = Integer | false \fR (default: same as \fIinet:setopts/2\fR)
\fBnodelay = true | false \fR (default: same as \fIinet:setopts/2\fR)
\fBpriority = Integer\fR (default: same as \fIinet:setopts/2\fR)
\fBsndbuf = Integer\fR (default: same as \fIinet:setopts/2\fR)
\fBrecbuf = Integer\fR (default: same as \fIinet:setopts/2\fR)
\fBsend_timeout = Integer | infinity\fR (default: same as \fIinet:setopts/2\fR)
\fBsend_timeout_close = true | false \fR (default: same as \fIinet:setopts/2\fR)
.RE
.TP
\fBserver_signature = String\fR
This directive sets the "Server: " output header to the custom value and
overloads the global one for this virtual server.
.TP
\fBsubconfig = File\fR
Same as \fBsubconfig\fR directive of the global part, but here files should only
contain directives allowed in the server part.
.TP
\fBsubconfigdir = Directory\fR
Same as \fBsubconfigdir\fR directive of the global part, but here files should only
contain directives allowed in server part.
.TP
\fBrhost = Host[:Port]\fR
This forces all local redirects issued by the server to go to Host. This is
useful when Yaws listens to a port which is different from the port that the
user connects to. For example, running Yaws as a non-privileged user makes it
impossible to listen to port 80, since that port can only be opened by a
privileged user. Instead Yaws listens to a high port number port, 8000, and
iptables are used to redirect traffic to port 80 to port 8000 (most NAT:ing
firewalls will also do this for you).
.TP
\fBrmethod = http | https\fR
This forces all local redirects issued by the server to use this method. This is
useful when an SSL off-loader, or stunnel, is used in front of Yaws.
.TP
\fBauth_log = true | false\fR
Enable or disable the auth log for this virtual server. Default is \fItrue\fR.
.TP
\fBaccess_log = true | false\fR
Setting this directive to false turns off traffic logging for this virtual
server. The default value is \fItrue\fR.
.TP
\fBlogger_mod = Module\fR
It is possible to set a special module that handles access and auth logging. The
default is to log all web server traffic to <Host>.access and <Host>.auth files
in the configured or default logdir.
.br
This module must implement the behaviour \fIyaws_logger\fR. Default value is
\fIyaws_log\fR.
The following functions should be exported:
\fBModule:open_log(ServerName, Type, LogDir)\fR
.RS 12
When Yaws is started, this function is called for this virtual server. If the
initialization is successful, the function must return \fI{true,State}\fR and if
an error occurred, it must return \fIfalse\fR.
.RE
.IP
\fBModule:close_log(ServerName, Type, State)\fR
.RS 12
This function is called for this virtual server when Yaws is stopped.
.RE
.IP
\fBModule:wrap_log(ServerName, Type, State, LogWrapSize)\fR
.RS 12
This function is used to rotate log files. It is regularly called by Yaws and
must return the possibly updated internal NewState.
.RE
.IP
\fBModule:write_log(ServerName, Type, State, Infos)\fR
.RS 12
When it needs to log a message, Yaws will call this function. The parameter
Infos is \fI{Ip,Req,InHdrs,OutHdrs,Time}\fR for an access log and
\fI{Ip,Path,Item}\fR for an auth log, where:
\fBIp\fR - IP address of the accessing client (as a tuple).
\fBReq\fR - the HTTP method, URI path, and HTTP version of the request (as a
#http_request{} record).
\fBInHdrs\fR - the HTTP headers which were received from the WWW client (as a
#headers{} record).
\fBOutHdrs\fR - the HTTP headers sent to the WWW client (as a #outh{} record)
\fBPath\fR - the URI path of the request (as a string).
\fBItem\fR - the result of an authentication request. May be \fI{ok,User}\fR,
\fI403\fR or \fI{401,Realm}\fR.
\fBTime\fR - The time taken to serve the request, in microseconds.
.RE
.IP
For all of these callbacks, \fBServerName\fR is the virtual server's name,
\fIType\fR is the atom access or auth and \fIState\fR is the internal state of
the logger.
.TP
\fBshaper = Module\fR
Defines a module to control access to this virtual server. Access can be
controlled based on the IP address of the client. It is also possible to
throttle HTTP requests based on the client's download rate. This module must
implement the behaviour \fIyaws_shaper\fR.
There is no such module configured by default.
.TP
\fBdir_listings = true | true_nozip | false\fR
Setting this directive to false disallows the automatic dir listing feature of
Yaws. A status code 403 Forbidden will be sent. Set to true_nozip to avoid the
auto-generated all.zip entries. Default is \fIfalse\fR.
.TP
\fBextra_cgi_vars = .....\fR
Add additional CGI or FastCGI variables. For example:
.nf
<extra_cgi_vars dir='/path/to/some/scripts'>
var = val
\&...
</extra_cgi_vars>
.fi
.TP
\fBstatistics = true | false\fR
Turns on/off statistics gathering for a virtual server. Default is \fIfalse\fR.
.TP
\fBfcgi_app_server = Host:Port\fR
The hostname and TCP port number of a FastCGI application server.
To specify an IPv6 address, put it inside square brackets (ex:
"[::1]:9000"). The TCP port number is not optional. There is no default
value.
.TP
\fBfcgi_trace_protocol = true | false\fR
Enable or disable tracing of FastCGI protocol messages as info log
messages. Disabled by default.
.TP
\fBfcgi_log_app_error = true | false\fR
Enable or disable logging of application error messages (output to stderr and
non-zero exit value). Disabled by default.
.TP
\fBdeflate = true | false\fR
Turns on or off deflate compression for a server. Default is \fIfalse\fR.
.TP
\fB<deflate> ... </deflate>\fR
This begins and ends the deflate compression configuration for this server. The
following items are allowed within a matching pair of <deflate> and </deflate>
delimiters.
\fBmin_compress_size = nolimit | Integer\fR
.RS 12
Defines the smallest response size that will be compressed. If nolimit is not
used, the specified value must be strictly positive. The default value is
\fInolimit\fR.
.RE
.IP
\fBcompression_level = none | default | best_compression | best_speed | 0..9\fR
.RS 12
Defines the compression level to be used. 0 (\fInone\fR), gives no
compression at all, 1 (\fIbest_speed\fR) gives best speed and 9
(\fIbest_compression\fR) gives best compression. The default value is
\fIdefault\fR.
.RE
.IP
\fBwindow_size = 9..15\fR
.RS 12
Specifies the zlib compression window size. It should be in the range 9 through
15. Larger values of this parameter result in better compression at the expense
of memory usage. The default value is \fI15\fR.
.RE
.IP
\fBmem_level = 1..9\fR
.RS 12
Specifies how much memory should be allocated for the internal compression
state. \fImem_level=1\fR uses minimum memory but is slow and reduces compression
ratio; \fImem_level=9\fR uses maximum memory for optimal speed. The default
value is \fI8\fR.
.RE
.IP
\fBstrategy = default | filtered | huffman_only\fR
.RS 12
This parameter is used to tune the compression algorithm. See \fBzlib(3erl)\fR
for more details on the \fIstrategy\fR parameter. The default value is
\fIdefault\fR.
.RE
.IP
\fBuse_gzip_static = true | false\fR
.RS 12
If true, Yaws will try to serve precompressed versions of static files. It will
look for precompressed files in the same location as original files that end in
".gz". Only files that do not fit in the cache are concerned. The default value
is \fIfalse\fR.
.RE
.IP
\fBmime_types = ListOfTypes | defaults | all\fR
.RS 12
Restricts the deflate compression to particular MIME types. The special value
\fIall\fR enable it for all types (It is a synonym of `*/*'). MIME types into
\fIListOfTypes\fR must have the form `type/subtype' or `type/*' (indicating all
subtypes of that type). Here is an example:
.nf
mime_types = default image/*
mime_types = application/xml application/xhtml+xml application/rss+xml
.fi
By default, the following MIME types are compressed (if
\fBdeflate\fR is set to true): \fItext/*, application/rtf, application/msword,
application/pdf, application/x-dvi, application/javascript,
application/x-javascript\fR. Multiple \fBmime_types\fR directive can be used.
.RE
.TP
\fBdocroot = Directory ...\fR
This makes the server serve all its content from Directory.
.br
It is possible to pass a space-separated list of directories as docroot. If this
is the case, the various directories will be searched in order for the requested
file. This also works with the ssi and yssi constructs where the full list of
directories will be searched for files to ssi/yssi include. Multiple docroot
directives can be used. You need at least one valid docroot, invalid docroots
are skipped with their associated auth structures.
.TP
\fBauth_skip_docroot = true | false\fR
If true, the docroot will not be searched for \fI.yaws_auth\fR files. This is
useful when the docroot is quite large and the time to search it is prohibitive
when Yaws starts up. Defaults to \fIfalse\fR.
.TP
\fBpartial_post_size = Integer | nolimit\fR
When a Yaws file receives large POSTs, the amount of data received in each chunk
is determined by this parameter. The default value is \fI10240\fR. Setting
it to nolimit is potentially dangerous.
.TP
\fBdav = true | false\fR
Turns on the DAV protocol for this server. The dav support in Yaws is highly
limited. If dav is turned on, .yaws processing of .yaws pages is turned
off. Default is \fIfalse\fR. The socket read timeout is supplied by the
keepalive_timeout setting. If the read is not done within the timeout, the POST
will fail.
.TP
\fBtilde_expand = true|false\fR
If this value is set to false Yaws will never do tilde expansion. The default is
\fIfalse\fR. tilde_expansion is the mechanism whereby a URL on the form
http://www.foo.com/~username is changed into a request where the docroot for
that particular request is set to the directory ~username/public_html/.
.TP
\fBallowed_scripts = ListOfSuffixes\fR
The allowed script types for this server. Recognized are `yaws', `cgi', `fcgi',
`php'. Default is \fIallowed_scripts = yaws php cgi fcgi\fR.
Note: for fcgi scripts, the FastCGI application server is only called if a local
file with the .fcgi extension exists. However, the contents of the local .fcgi
file are ignored.
.TP
\fBtilde_allowed_scripts = ListOfSuffixes\fR
The allowed script types for this server when executing files in a users
public_html folder Recognized are `yaws', `cgi', `fcgi', `php'. Default is
\fItilde_allowed_scripts =\fR i.e. empty
.TP
\fBindex_files = ListOfResources\fR
This directive sets the list of resources to look for, when a directory is
requested by the client. If the last entry begins with a `/', and none of the
earlier resources are found, Yaws will perform a redirect to this uri.
Default is \fIindex_files = index.yaws index.html index.php\fR.
.TP
\fBappmods = ListOfModuleNames\fR
If any of the names in ListOfModuleNames appear as components in the path for a
request, the path request parsing will terminate and that module will be
called. There is also an alternate syntax for specifying the appmods if we don't
want our internal erlang module names to be exposed in the URL paths. We can
specify
.nf
appmods = <Path1, Module1> <Path2, Modules2> ...
.fi
Assume for example that we have the URL
http://www.hyber.org/myapp/foo/bar/baz?user=joe while we have the module foo
defined as an appmod, the function foo:out(Arg) will be invoked instead of
searching the filesystems below the point foo.
.br
The Arg argument will have the missing path part supplied in its appmoddata
field.
It is also possible to exclude certain directories from appmod processing. This
is particulaly interesting for '/' appmods. Here is an example:
.nf
appmods = </, myapp exclude_paths icons js top/static>
.fi
The above configuration will invoke the 'myapp' erlang module on everything
except any file found in directories 'icons', 'js' and 'top/static' relative to
the docroot.
.TP
\fBdispatchmod = DispatchModule\fR
Set \fIDispatchModule\fR as a server-specific request dispatching
module. Yaws expects \fIDispatchModule\fR to export a \fIdispatch/1\fR
function. When it receives a request, Yaws passes an \fI#arg{}\fR record to
the dispatch module's \fIdispatch/1\fR function, which returns one of the
following atom results:
.RS 12
\fBdone\fR - this indicates the dispatch module handled the request itself
and already sent the response, and Yaws should resume watching for new
requests on the connection
\fBclosed\fR - same as \fIdone\fR but the \fIDispatchModule\fR also closed
the connection
\fBcontinue\fR - the dispatch module has decided not to handle the request,
and instead wants Yaws to perform its regular request dispatching
.RE
.IP
Note that when \fIDispatchModule\fR handles a request itself, Yaws does not
support tracing, increment statistics counters or allow traffic shaping for
that request. It does however still keep track of maximum keepalive uses on
the connection.
.TP
\fBerrormod_404 = Module\fR
It is possible to set a special module that handles 404 Not Found messages. The
function \fIModule:out404(Arg, GC, SC)\fR will be invoked. The arguments are
.RS 12
\fBArg\fR - a #arg{} record
\fBGC\fR - a #gconf{} record (defined in yaws.hrl)
\fBSC\fR - a #sconf{} record (defined in yaws.hrl)
.RE
.IP
The function can and must do the same things that a normal \fIout/1\fR does.
.TP
\fBerrormod_401 = Module\fR
It is possible to set a special module that handles 401 Unauthorized
messages. This can for example be used to display a login page instead. The
function \fIModule:out401(Arg, Auth, Realm)\fR will be invoked. The arguments
are
.RS 12
\fBArg\fR - a #arg{} record
\fBAuth\fR - a #auth{} record
\fBRealm\fR - a string
.RE
.IP
The function can and must do the same things that a normal \fIout/1\fR does.
.TP
\fBerrormod_crash = Module\fR
It is possible to set a special module that handles the HTML generation of
server crash messages. The default is to display the entire formatted crash
message in the browser. This is good for debugging but not in production.
.br
The function \fIModule:crashmsg(Arg, SC, Str)\fR will be called. The \fIStr\fR
is the real crash message formatted as a string.
.br
The function must return, \fI{content,MimeType,Cont}\fR or \fI{html, Str}\fR or
\fI{ehtml, Term}\fR. That data will be shipped to the client.
.TP
\fBexpires = ListOfExpires\fR
Controls the setting of the \fIExpires\fR HTTP header and the \fImax-age\fR
directive of the \fICache-Control\fR HTTP header in server responses for
specific MIME types. The expiration date can be set as relative to either the
time the source file was last modified; as the time of the client access; or as
always in order to empty the cache altogether. ListOfExpires is defined as
follows:
.nf
expires = <MimeType1, access+Seconds> <MimeType2, modify+Seconds> <MimeType3, always> ...
.fi
A MimeType can also have a wildcard as subtype or both as subtype and type,
like type/* or */*.
These HTTP headers are an instruction to the client about the document's
validity and persistence. If cached, the document may be fetched from the cache
rather than from the source until this time has passed. After that, the cache
copy is considered "expired" and invalid, and a new copy must be obtained from
the source. Here is an example:
.nf
expires = <image/gif, access+2592000> <image/png, access+2592000>
expires = <image/jpeg, access+2592000> <text/css, access+2592000>
expires = <text/*, always>
.fi
and here is another:
.nf
expires = <*/*, always>
.fi
.TP
\fBarg_rewrite_mod = Module\fR
It is possible to install a module that rewrites all the Arg #arg{} records
at an early stage in the Yaws server. This can be used to do various
things such as checking a cookie, rewriting paths etc. An arg_rewrite_mod
must export an \fIarg_rewrite/1\fR function taking and returning an #arg{}
record. If the function wants to return a response, it must set the
#arg.state field of its return value to an instance of the
#rewrite_response{} record.
The module \fIyaws_vdir\fR can be used in case you want to serve static content
that is not located in your docroot. See the example at the bottom of this man
page for how to use the \fIopaque\fR + \fIvdir\fR elements to instruct the
\fIyaws_vdir\fR module what paths to rewrite.
.TP
\fBstart_mod = Module\fR
Defines a user provided callback module. At startup of the server,
Module:start/1 will be called. The #sconf{} record (defined in yaws.hrl) will
be used as the input argument. This makes it possible for a user application to
synchronize the startup with the Yaws server as well as getting hold of user
specific configuration data, see the explanation for the <opaque> context.
.TP
\fBrevproxy = Prefix Url [intercept_mod Module]\fR
Make Yaws a reverse proxy. \fIPrefix\fR is a path inside our own docroot
and \fIUrl\fB argument is a URL pointing to a website we want to "mount"
under the \fIPrefix\fR path. This example:
.nf
revproxy = /tmp/foo http://yaws.hyber.org
.fi
makes the hyber website appear under \fI/tmp/foo\fR.
It is possible to have multiple reverse proxies inside the same server.
You can optionally configure an interception module for each reverse proxy,
allowing your application to examine and modify requests and HTTP headers
as they pass through the proxy from client to backend server and also
examine and modify responses and HTTP headers as they return from the
backend server through the proxy to the client.
You specify an interception module by including the optional
\fIintercept_mod\fR keyword followed by \fIModule\fR, which should be the
name of your interception module.
An interception module is expected to export two functions:
\fIrewrite_request/2\fR and \fIrewrite_response/2\fR. The two arguments
passed to \fIrewrite_request/2\fR function are a \fI#http_request{}\fR record
and a \fI#headers{}\fR record, whereas \fIrewrite_response/2\fR function
takes a \fI#http_response{}\fR record and also a \fI#headers{}\fR record. You
can find definitions for these record types in the \fIyaws_api.hrl\fR
header file. Each function can examine each record instance and can either
return each original instance or can return a modified copy of each
instance in its response. The \fIrewrite_request/2\fR function should
return a tuple of the following form:
.nf
\fI{ok, #http_request{}, #headers{}}\fR
.fi
and the \fIrewrite_response/2\fR function should similarly return a tuple
of the following form:
.nf
\fI{ok, #http_response{}, #headers{}}\fR
.fi
A \fI#headers{}\fR record can easily be manipulated in an interceptor using
the functions listed below:
.nf
\fIyaws_api:set_header/2\fR, \fIyaws_api:set_header/3\fR
\fIyaws_api:get_header/2\fR, \fIyaws_api:get_header/3\fR
\fIyaws_api:delete_header/2\fR
.fi
Any failures in your interception module's functions will result in HTTP
status code 500, indicating an internal server error.
.TP
\fBfwdproxy = true|false\fR
Make Yaws a forward proxy. By enabling this option you can use Yaws as a proxy
for outgoing web traffic, typically by configuring the proxy settings in a
web-browser to explicitly target Yaws as its proxy server.
.TP
\fBservername = Name\fR
If we're virthosting several servers and want to force a server to match
specific Host: headers we can do this with the "servername" directive. This name
doesn't necessarily have to be the same as the the name inside <server Name> in
certain NAT scenarios. Rarely used feature.
.TP
\fBserveralias = ListOfNames\fR
This directive sets the alternate names for a virtual host. A server alias may
contain wildcards:
.RS 12
'*' matches any sequence of zero or more characters
'?' matches one character unless that character is a period ('.')
.RE
.IP
Multiple \fBserveralias\fR directives may be used. Here is an example:
.nf
<server server.domain.com>
serveralias = server server2.domain.com server2
serveralias = *.server.domain.com *.server?.domain.com
...
</server>
.fi
.TP
\fBphp_handler = <Type, Spec>\fR
Set handler to interpret .php files. It can be one of the following definitions:
\fBphp_handler = <cgi, Filename>\fR - The name of (and possibly path to) the php
executable used to interpret php scripts (if allowed).
\fBphp_handler = <fcgi, Host:Port>\fR - Use the specified fastcgi server to
interpret .php files (if allowed).
.RS 12
Yaws does not start the PHP interpreter in fastcgi mode for you. To run PHP in
fastcgi mode, call it with the -b option. For example:
.nf
php5-cgi -b '127.0.0.1:54321'
.fi
This starts a php5 in fastcgi mode listening on the local network interface. To
make use of this PHP server from Yaws, specify:
.nf
php_handler = <fcgi, 127.0.0.1:54321>
.fi
If you need to specify an IPv6 address, use square brackets:
.nf
php_handler = <fcgi, [::1]:54321>
.fi
The PHP interpreter needs read access to the files it is to serve. Thus, if you
run it in a different security context than Yaws itself, make sure it has access
to the .php files.
.br
Please note that anyone who is able to connect to the php fastcgi server
directly can use it to read any file to which it has read access. You should
consider this when setting up a system with several mutually untrusted instances
of php.
.RE
.IP
\fBphp_handler = <extern, Module:Function | Node:Module:Function>\fR - Use an
external handler, possibly on another node, to interpret .php files (if
allowed).
.RS 12
To interpret a .php file, the function \fIModule:Function(Arg)\fR will be
invoked (Evaluated inside a rpc call if a \fINode\fR is specified), where Arg is
an #arg{} record.
.br
The function must do the same things that a normal out/1 does.
.RE
.IP
Default value is \fI<cgi, "/usr/bin/php-cgi">\fR.
.TP
\fBphpfcgi = Host:Port\fR
\fBthis target is deprecated. use 'php_handler' target in server part
instead.\fR
.br
Using this directive is the same as: php_handler = <fcgi, Host:Port>.
.TP
\fBdefault_type = MimeType\fR
Overloads the global \fBdefault_type\fR value for this virtual server.
.TP
\fBdefault_charset = Charset\fR
Overloads the global \fBdefault_charset\fR value for this virtual server.
.TP
\fBmime_types_file = File\fR
Overloads the global \fBmime_type_file\fR value for this virtual
server. Mappings defined in \fIFile\fR will not overload those defined by
\fBadd_types\fR directives in the global part.
.TP
\fBadd_types = ListOfTypes\fR
Overloads the global \fBadd_types\fR values for this virtual server. If a
mapping is defined in the global part and redefined in a server part using this
directive, then it is replaced. Else it is kept.
.TP
\fBadd_charsets = ListOfCharsets\fR
Overloads the global \fBadd_charsets\fR values for this virtual server. If a
mapping is defined in the global part and redefined in a server part using this
directive, then it is replaced. Else it is kept.
.TP
\fBnslookup_pref = [inet | inet6]\fR
For fcgi servers and revproxy URLs, define the name resolution
preference. For example, to perform only IPv4 name resolution, use
[inet]. To do both IPv4 and IPv6 but try IPv6 first, use [inet6, inet].
Default value is [inet].
.TP
\fB<ssl> ... </ssl>\fR
This begins and ends an SSL configuration for this server. It's possible to
virthost several SSL servers on the same IP/Port. If SNI support is disabled or
not supported, they must share the same certificate configuration. In this
situation, it is complicated to virthost several SSL servers on the same IP/Port
since the certificate is typically bound to a domainname in the common name part
of the certificate. One solution to this problem is to have a certificate with
multiple subjectAltNames. If SNI support is enabled, SSL servers on the same
IP/Port can have their own SSL configuration with a different SSL certificate
for each one. See the global \fBsni\fR directive.
The SNI support was introduced in the SSL application in Erlang/OTP 18.0. It is
an extension to the TLS protocol (RFC 4366), which allows the client to include
the requested hostname in the first message of its SSL handshake.
See also http://wiki.cacert.org/VhostTaskForce#Interoperability_Test for browser
compatibility.
\fBkeyfile = File\fR
.RS 12
Specifies which file contains the private key for the certificate. If not
specified then the certificate file will be used.
.RE
.IP
\fBcertfile = File\fR
.RS 12
Specifies which file contains the certificate for the server.
.RE
.IP
\fBcacertfile = File\fR
.RS 12
A file containing trusted certificates to use during client authentication and
to use when attempting to build the server certificate chain. The list is also
used in the list of acceptable client CAs passed to the client when a
certificate is requested.
.RE
.IP
\fBdhfile = File\fR
.RS 12
A file containing PEM-encoded Diffie-Hellman parameters to be used by
the server if a cipher suite using Diffie-Hellman key exchange is
negotiated. If not specified, default parameters are used.
.RE
.IP
\fBverify = verify_none | verify_peer\fR
.RS 12
Specifies the level of verification the server does on client certs. Setting
\fIverify_none\fR means that the x509 validation will be skipped (no certificate
request is sent to the client), \fIverify_peer\fR means that a certificate
request is sent to the client (x509 validation is performed.
You might want to use \fBfail_if_no_peer_cert\fR in combination with
\fIverify_peer\fB.
.RE
.IP
\fBfail_if_no_peer_cert = true | false\fR
.RS 12
If \fBverify\fR is set to \fIverify_peer\fR and set to \fItrue\fR the connection
will fail if the client does not send a certificate (i.e. an empty
certificate). If set to \fIfalse\fR the server will fail only if an invalid
certificate is supplied (an empty certificate is considered valid).
.RE
.IP
\fBdepth = Int\fR
.RS 12
Specifies the depth of certificate chains the server is prepared to follow when
verifying client certs. For the OTP new SSL implementation it is also used to
specify how far the server, i.e. we, shall follow the SSL certificates we
present to the clients. Hence, using self-signed certs, we typically need to set
this to 0.
.RE
.IP
\fBpassword = String\fR
.RS 12
If the private key is encrypted on disc, this password is the
3DES key to decrypt it.
.RE
.IP
\fBciphers = String\fR
.RS 12
This string specifies the SSL cipher string. The syntax of the SSL cipher string
is an erlang term compliant with the output of ssl:cipher_suites().
.nf
ciphers = "[{dhe_rsa,aes_256_cbc,sha}, \\
{dhe_dss,aes_256_cbc,sha}]"
.fi
.RE
.IP
\fBsecure_renegotiate = true | false\fR
.RS 12
Specifies whether to reject renegotiation attempt that does not live up to
RFC 5746. By default \fBsecure_renegotiate\fR is set to false i.e. secure
renegotiation will be used if possible but it will fallback to unsecure
renegotiation if the peer does not support RFC 5746.
.RE
.IP
\fBclient_renegotiation = true | false\fR
.RS 12
Enables or disables the Erlang/OTP SSL application client renegotiation
option. Defaults to true. See the \fIssl\fR manual page at
http://www.erlang.org/doc/man/ssl.html for more details.
\fBWARNING: This option was introduced in the SSL application in Erlang/OTP
18.0, so Yaws ignores it for previous releases.\fR
.RE
.IP
\fBhonor_cipher_order = true | false\fR
.RS 12
If true (the default), use the server's preference for cipher selection. If
false, use the client's preference.
\fBWARNING: This option was introduced in the SSL application in Erlang/OTP
17.0, so Yaws ignores it for previous releases.\fR
.RE
.IP
\fBprotocol_version = ProtocolList\fR
.RS 12
Specifies the list of SSL protocols that will be supported. If not set,
defaults to all protocols supported by the erlang \fBssl\fR
application. For example, to support only TLS versions 1.2, 1.1, and 1:
.nf
protocol_version = tlsv1.2, tlsv1.1, tlsv1
.fi
.RE
.IP
\fBrequire_sni = true | false\fR
.RS 12
If \fItrue\fR,the server will reject non SNI clients and clients providing an
unknown SNI hostname (this last remark is only relevant for the first virtual
server of a SSL group). This directive is ignored if SNI support is disabled (or
not supported).
Default is \fIfalse\fR.
.RE
.TP
\fB<redirect> ... </redirect>\fR
Defines a redirect mapping. The following items are allowed within a matching
pair of <redirect> and </redirect> delimiters.
We can have a series of redirect rules in one of the formats below:
.nf
Path = URL
Path = code
Path = code URL
.fi
\fBPath\fR must be an url-decoded path beginning with a slash. \fBURL\fR may be
either a relative URL (a path beginning with a slash), or an absolute URL. In
the first case, the \fIscheme:hostname:port\fR of the current server will be
added. All accesses to \fBPath\fR will be redirected to \fBURL/Path\fR (or
\fBscheme:hostname:port/URL/Path\fR if \fBURL\fR is relative). \fBURL\fR must be
url-encoded. Note that the original path is appended to the redirected URL.
For example, assume we have the following redirect configuration:
.nf
<redirect>
/foo = http://www.mysite.org/zapp
/bar = /tomato.html
</redirect>
.fi
Assuming this config resides on a site called http://abc.com, we have the
following redirects:
.nf
http://abc.com/foo -> http://www.mysite.org/zapp/foo
http://abc.com/foo/test -> http://www.mysite.org/zapp/foo/test
http://abc.com/bar -> http://abc.com/tomato.html/bar
http://abc.com/bar/x/y/z -> http://abc.com/tomato.html/bar/x/y/z
.fi
By default, Yaws will perform a 302 redirect. The HTTP status code can be
changed using the \fBcode\fR parameter. Note that the status code must be known
by Yaws.
.RS
.IP \[bu] 3
For 3xx status codes, the \fBURL\fR parameter must be present and will be used
to build the new location.
.IP \[bu]
For other status codes (1xx, 2xx, 4xx and 5xx), it can be omitted. In the
absence of \fBURL\fR, Yaws will return a generic response with the specified
status code.
.IP \[bu]
Otherwise, the \fBURL\fR parameter must be a relative URL and will be
used to customize the response.
.RE
.RS 7
Sometimes we do not want to have the original path appended to the redirected
path. To get that behaviour we specify the config with '==' instead of '='.
.nf
<redirect>
/foo == http://www.mysite.org/zapp
/bar = /tomato.html
</redirect>
.fi
Now a request for http://abc.com/foo/x/y/z simply gets redirected to
http://www.mysite.org/zapp. This is typically used when we simply want a static
redirect at some place in the docroot.
When we specify a relative URL as the target for the redirect, the redirect
will be to the current http(s) server.
.RE
.TP
\fB<auth> ... </auth>\fR
Defines an auth structure. The following items are allowed within a matching
pair of <auth> and </auth> delimiters.
\fBdocroot = Docroot \fR
.RS 12
If a docroot is defined, this auth structure will be tested only for requests in
the specified docroot. No docroot configured means all docroots. If two auth
structures are defined, one with a docroot and one with no docroot, the first of
both overrides the second one for requests in the configured docroot.
.RE
.IP
\fBdir = Dir\fR
.RS 12
Makes Dir to be controlled by WWW-authenticate headers. In order for a user to
have access to WWW-Authenticate controlled directory, the user must supply a
password. The Dir must be specified relative to the docroot. Multiple dir can
be used. If no dir is set, the default value, \fI"/"\fR, will be used.
.RE
.IP
\fBrealm = Realm\fR
.RS 12
In the directory defined here, the WWW-Authenticate Realm is set to this value.
.RE
.IP
\fBauthmod = AuthMod\fR
.RS 12
If an auth module is defined then AuthMod:auth(Arg, Auth) will be called for all
access to the directory. The auth/2 function should return one of: true, false,
{false, Realm}, {appmod, Mod}. If {appmod, Mod} is returned then a call to
Mod:out401(Arg, Auth, Realm) will be used to deliver the content. If
errormod_401 is defined, the call to Mod will be ignored. (Mod:out(Arg) is
deprecated).
This can, for example, be used to implement cookie authentication. The auth()
callback would check if a valid cookie header is present, if not it would return
{appmod, ?MODULE} and the out401/1 function in the same module would return
{redirect_local, "/login.html"}.
.RE
.IP
\fBuser = User:Password | "User:{Algo}Hash" | "User:{Algo}$Salt$Hash"\fR
.RS 12
Inside this directory, the user \fIUser\fR has access if the user supplies the
password \fIPassword\fR in the popup dialogue presented by the browser. It is
also possible to provide a hashed password, encoded in base64. In that case, the
algorithm used to hash the password must be set. \fIAlgo\fR must be a one of the
following algorithms:
.nf
md5 | ripemd160 | sha | sha224 | sha256 | sha384 | sha512
.fi
It is possible to use salted hashes. If so, the \fISalt\fR must be provided,
encoded in base64. We can obviously have several of these value inside a single
<auth> </auth> pair.
.RE
.IP
\fBpam service = \fIpam-service\fR\fR
.RS 12
If the item \fBpam\fR is part of the auth structure, Yaws will also try to
authenticate the user using "pam" using the pam \fIservice\fR indicated. Usual
services are typically found under /etc/pam.d. Usual values are "system-auth"
etc.
pam authentication is performed by an Erlang port program which is typically
installed as suid root by the Yaws install script.
.RE
.IP
\fBallow = all | ListOfHost\fR
.RS 12
The \fIallow\fR directive affects which hosts can access an area of the
server. Access can be controlled by IP address or IP address range. If all is
specified, then all hosts are allowed access, subject to the configuration of
the \fIdeny\fR and \fIorder\fR directives. To allow only particular hosts or
groups of hosts to access the server, the host can be specified in any of the
following formats:
\fBA full IP address\fR
.nf
allow = 10.1.2.3
allow = 192.168.1.104, 192.168.1.205
.fi
\fBA network/netmask pair\fR
.nf
allow = 10.1.0.0/255.255.0.0
.fi
\fBA network/nnn CIDR specification\fR
.nf
allow = 10.1.0.0/16
.fi
.RE
.IP
\fBdeny = all | ListOfHost\fR
.RS 12
This directive allows access to the server to be restricted based on IP
address. The arguments for the \fIdeny\fR directive are identical to the
arguments for the \fIallow\fR directive.
.RE
.IP
\fBorder = Ordering\fR
.RS 12
The \fIorder\fR directive, along with \fIallow\fR and \fIdeny\fR directives,
controls a three-pass access control system. The first pass processes either all
\fIallow\fR or all \fIdeny\fR directives, as specified by the \fIorder\fR
directive. The second pass parses the rest of the directives (\fIdeny\fR or
\fIallow\fR). The third pass applies to all requests which do not match either
of the first two.
Ordering is one of (Default value is \fIdeny,allow\fR):
.TP
\fBallow,deny\fR
First, all \fIallow\fR directives are evaluated; at least one must match, or the
request is rejected. Next, \fIdeny\fR directives are evaluated. If any matches,
the request is rejected. Last, any requests which do not match an \fIallow\fR or
a \fIdeny\fR directive are denied by default.
.TP
\fBdeny,allow\fR
First, all \fIdeny\fR directives are evaluated; if any matched, the request is
denied unless it also matches an \fIallow\fR directive. Any requests which do
not match any \fIallow\fR or \fIdeny\fR directives are permitted.
.RE
.TP
\fB<opaque> ... </opaque>\fR
This begins and ends an opaque configuration context for this server, where 'Key
= Value' directives can be specified. These directives are ignored by Yaws
(hence the name opaque), but can be accessed as a list of tuples
\fI{Key,Value}\fR stored in the #sconf.opaque record entry. See also the
description of the \fIstart_mod\fR directive.
This mechanism can be used to pass data from a surrounding application into the
individual .yaws pages.
.SH EXAMPLES
The following example defines a single server on port 80.
.nf
logdir = /var/log/yaws
<server www.mydomain.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www
</server>
.fi
.PP
And this example shows a similar setup but two web servers on the same IP
address.
.nf
logdir = /var/log/yaws
<server www.mydomain.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www
</server>
<server www.funky.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www_funky_org
</server>
.fi
.PP
An example with www-authenticate and no access logging at all.
.nf
logdir = /var/log/yaws
<server www.mydomain.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www
access_log = false
<auth>
dir = secret/dir1
realm = foobar
user = jonny:verysecretpwd
user = benny:thequestion
user = ronny:havinganamethatendswithy
</auth>
</server>
.fi
.PP
An example specifying a user defined module to be called at startup, as well as
some user specific configuration.
.nf
<server www.funky.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www_funky_org
start_mod = btt
<opaque>
mydbdir = /tmp
mylogdir = /tmp/log
</opaque>
</server>
.fi
.PP
An example specifying the GSSAPI/SPNEGO module (authmod_gssapi) to be used for
authentication. This module requires egssapi version 0.1~pre2 or later available
at http://www.hem.za.org/egssapi/.
The Kerberos5 keytab is specified as 'keytab = File' directive in opaque. This
keytab should contain the keys of the HTTP service
principal, 'HTTP/www.funky.org' in this example.
.nf
<server www.funky.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www_funky_org
start_mod = authmod_gssapi
<auth>
authmod = authmod_gssapi
dir = secret/dir1
</auth>
<opaque>
keytab = /etc/yaws/http.keytab
</opaque>
</server>
.fi
.PP
And finally a slightly more complex example with two servers on the same IP, and
one SSL server on a different IP.
When there are more than one server on the same IP, and they have different
names the server must be able to choose one of them if the client doesn't send a
Host: header. Yaws will choose the first one defined in the conf file.
.nf
logdir = /var/log/yaws
max_num_cached_files = 8000
max_num_cached_bytes = 6000000
<server www.mydomain.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www
</server>
<server www.funky.org>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www_funky_org
</server>
<server www.funky.org>
port = 443
listen = 192.168.128.32
docroot = /var/yaws/www_funky_org
<ssl>
keyfile = /etc/funky.key
certfile = /etc/funky.cert
password = gazonk
</ssl>
</server>
.fi
.PP
Finally an example with virtual directories, vdirs.
.nf
<server server.domain>
port = 80
listen = 192.168.128.31
docroot = /var/yaws/www
arg_rewrite_mod = yaws_vdir
<opaque>
vdir = "/virtual1/ /usr/local/somewhere/notrelated/to/main/docroot"
vdir = "/myapp/ /some/other/path can include/spaces"
vdir = "/icons/ /usr/local/www/yaws/icons"
</opaque>
</server>
.fi
.PP
The first defined vdir can then be accessed at or under
http://server.domain/virtual1/ or http://server.domain/virtual1
.SH AUTHOR
Written by Claes Wikstrom
.SH "SEE ALSO"
.BR yaws (1)
.BR erl (1)