6 htparser - Root HTTP server for use with ashd(7)
10 *htparser* [*-hSf*] [*-u* 'USER'] [*-r* 'ROOT'] [*-p* 'PIDFILE'] 'PORTSPEC'... `--` 'ROOT' ['ARGS'...]
15 The *htparser* program is the root HTTP server of *ashd*(7). It
16 listens to specified TCP ports, speaks HTTP with connecting clients,
17 and passes requests on to the root handler program.
19 When *htparser* starts, it will first begin listening to all ports
20 specified by 'PORTSPEC'. Once all ports have been bound successfully,
21 it will fork off and start the root handler specified by 'ROOT',
22 searching the *PATH* environment variable if necessary, and passing it
23 all the 'ARGS' as command-line arguments. Only after that will
24 *htparser* do any daemonizing or chrooting as specified by options.
26 The root handler must be a persistent program as specified in
27 *ashd*(7). If the handler program exits, *htparser* will exit too,
28 following the procedure described below under SIGNALS.
33 'PORTSPEC' is given in the form
34 'HANDLER'[*:*'PAR'[*=*'VAL'][(*,*'PAR'[*=*'VAL'])...]]. The
35 'PAR'='VAL' pairs are used for specifying key-value arguments to the
36 'HANDLER'. An example of a valid 'PORTSPEC' is `plain:port=8080`.
38 Currently, the available 'HANDLERs' are *plain* and *ssl*, for
39 handling plain TCP connections and SSL/TLS-protected connections,
40 respectively. For details regarding the arguments that each handler
41 accepts, simply run *htparser* with 'HANDLER'*:help*. For example, the
42 command "`htparser ssl:help`" will display help for the *ssl* handler
43 to standard output and then exit.
45 The port specifications must be followed by the `--` argument to
46 distinguish them from the root handler specification.
53 Print a brief usage message on standard output and exit.
57 Log messages to *syslog*(3) instead of standard error. Also
58 sets the ASHD_USESYSLOG environment variable in the root
59 handler process, which indicates to the standard ashd programs
64 Daemonize after all specified ports have been successfully
65 bound and the root handler has been started.
69 Change UID to 'USER' once all specified ports have been
70 successfully bound and the root handler has been
71 started. 'USER' must be specified symbolically (i.e. not as a
76 Change root directory to 'ROOT' once all specified ports have
77 been successfully bound and the root handler has been started.
81 After having daemonized, write the PID of the new process to
89 Upon first reception, `htparser` closes all listening ports
90 and the socket to the root handler, but continues to serve all
91 currently ongoing requests until none remain, not keeping the
92 connections open for keep-alive. Upon second reception,
93 `htparser` shuts down completely.
98 `htparser plain -- dirplex /srv/www`::
100 This simple invocation will listen for HTTP requests on port
101 80 and use *dirplex*(1) to serve files from the /srv/www
104 `htparser plain:port=8080 -- dirplex /srv/www`::
106 The same as the previous example, but uses port 8080 instead,
107 so that it can be started without root privileges.
109 `htparser plain ssl:cert=/etc/ssl/private/web.pem -- dirplex /srv/www`::
111 The same as above, but will listen on port 443 for SSL
112 connections as well. The file `/etc/ssl/private/web.pem` needs
113 to contain both the server certificate and its private key.
115 `htparser plain -- sudo -u www-user dirplex /srv/www`::
117 The same as above, but uses *sudo*(8) to ensure that *dirplex*
118 runs as a non-privileged user.
120 `htparser -f -u nobody -r /var/empty plain -- patplex /etc/ashd/rootpat`::
122 Will listen to port 80 for plain HTTP requests and use the
123 *patplex*(1) program to serve requests based on patterns
124 specified in the `/etc/ashd/rootpat` file. *htparser* will
125 daemonize, change user-ID to `nobody` and change its root
126 directory to `/var/empty` once *patplex* has been
127 started. Note that *patplex* still runs as root in the normal
128 file system, so that it can start other handler programs as
131 `htparser -f plain -- errlogger -n ashd dirplex /srv/www`::
133 The same as the first example, but will daemonize and use the
134 *errlogger*(1) program to ensure that any errors or other
135 messages written by any handler program to its stderr are
136 recorded in the *syslog*(3).
141 *htparser* strips away all headers from incoming requests that begin
142 with the `X-Ash-` prefix, and adds the following headers to requests:
146 The IP address that the client connected from. May be an IPv6
151 The client-side port number of the TCP connection.
153 *X-Ash-Server-Address*::
155 The IP address of the server where the connection was
156 accepted. May be an IPv6 address.
158 *X-Ash-Server-Port*::
160 The server-side port number of the TCP connection.
164 Either *http* or *https*, depending on whether the request was
165 received by the *plain* or the *ssl* handler.
169 Fredrik Tolf <fredrik@dolda2000.com>