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)