PUBLIC-INBOX-DAEMON(8)     public-inbox user manual     PUBLIC-INBOX-DAEMON(8)

NAME
       public-inbox-daemon - common usage for public-inbox network daemons

SYNOPSIS
               public-inbox-httpd
               public-inbox-imapd
               public-inbox-nntpd

DESCRIPTION
       This manual describes common options and behavior for public-inbox
       network daemons.  Network daemons for public-inbox provide read-only
       NNTP, IMAP and HTTP access to public-inboxes.  Write access to a
       public-inbox will never be required to run these.

       These daemons are implemented with a common core using non-blocking
       sockets and optimized for fairness; even with thousands of connected
       clients over slow links.

       They also provide graceful shutdown/upgrade support to avoid breaking
       existing connections during software upgrades.

       These daemons may also utilize multiple pre-forked worker processes to
       take advantage of multiple CPUs.

OPTIONS
       -l ADDRESS
       --listen ADDRESS
           This takes an absolute path to a Unix socket or HOST:PORT to listen
           on.  For example, to listen to TCP connections on port 119, use:
           "-l 0.0.0.0:119".  This may also point to a Unix socket ("-l
           /path/to/http.sock") for a reverse proxy like nginx(8) to use.

           May be specified multiple times to allow listening on multiple
           sockets.

           This does not need to be specified at all if relying on
           systemd.socket(5) or similar

           Default: server-dependent unless socket activation is used with
           systemd(1) or similar (see systemd.socket(5)).

       -1
       --stdout PATH
           Specify an appendable path to redirect stdout descriptor (1) to.
           Using this is preferable to setting up the redirect externally
           (e.g. >>/path/to/log in shell) since it allows SIGUSR1 to be
           handled (see "SIGNALS" in SIGNALS below).

           Default: /dev/null

       -2 PATH
       --stderr PATH
           Like "--stdout", but for the stderr descriptor (2).

       -W
       --worker-processes
           Set the number of worker processes.

           Normally, this should match the number of CPUs on the system to
           take full advantage of the hardware.  However, users of memory-
           constrained systems may want to lower this.

           Setting this to zero ("-W0") disables the master/worker split;
           saving some memory but removing the ability to use SIGTTIN to
           increase worker processes or have the worker restarted by the
           master on crashes.

           Default: 1

SIGNALS
       Most of our signal handling behavior is copied from nginx(8) and/or
       starman(1); so it is possible to reuse common scripts for managing
       them.

       SIGUSR1 Reopens log files pointed to by --stdout and --stderr options.

       SIGUSR2 Spawn a new process with the intention to replace the running
               one.  See "UPGRADING" below.

       SIGHUP  Reload config files associated with the process.  (Note: broken
               for public-inbox-httpd(1) only in <= 1.6)

       SIGTTIN Increase the number of running workers processes by one.

       SIGTTOU Decrease the number of running worker processes by one.

       SIGWINCH
               Stop all running worker processes.   SIGHUP or SIGTTIN may be
               used to restart workers.

       SIGQUIT Gracefully terminate the running process.

       SIGTTOU, SIGTTIN, SIGWINCH all have no effect when worker processes are
       disabled with "-W0" on the command-line.

ENVIRONMENT
       PI_CONFIG
               The default config file, normally "~/.public-inbox/config".
               See public-inbox-config(5)

       LISTEN_FDS, LISTEN_PID
               Used by systemd (and compatible) installations for socket
               activation.  See systemd.socket(5) and sd_listen_fds(3).

       PERL_INLINE_DIRECTORY
               Pointing this to point to a writable directory enables the use
               of Inline and Inline::C extensions which may provide platform-
               specific performance improvements.  Currently, this enables the
               use of vfork(2) which speeds up subprocess spawning with the
               Linux kernel.

               public-inbox will never enable Inline::C automatically without
               this environment variable set or
               "~/.cache/public-inbox/inline-c" created by a user. See Inline
               and Inline::C for more details.

UPGRADING
       There are two ways to upgrade a running process.

       Users of process management systems with socket activation (systemd(1)
       or similar) may rely on multiple instances For systemd, this means
       using two (or more) '@' instances for each service (e.g.
       "SERVICENAME@INSTANCE") as documented in systemd.unit(5).

       Users of traditional SysV init may use SIGUSR2 to spawn a replacement
       process and gracefully terminate the old process using SIGQUIT.

       In either case, the old process will not truncate running responses; so
       responses to expensive requests do not get interrupted and lost.

CONTACT
       Feedback welcome via plain-text mail to <mailto:meta@public-inbox.org>

       The mail archives are hosted at <https://public-inbox.org/meta/> and
       <http://4uok3hntl7oi7b4uf4rtfwefqeexfzil2w6kgk2jn5z2f764irre7byd.onion/meta/>

COPYRIGHT
       Copyright 2013-2021 all contributors <mailto:meta@public-inbox.org>

       License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>

SEE ALSO
       public-inbox-httpd(1), public-inbox-imapd(1), public-inbox-nntpd(1)

public-inbox.git                  1993-10-02            PUBLIC-INBOX-DAEMON(8)