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diff --git a/doc/s6-rc-init.html b/doc/s6-rc-init.html index 143a0f4..f2bd8e1 100644 --- a/doc/s6-rc-init.html +++ b/doc/s6-rc-init.html @@ -20,149 +20,75 @@ <p> s6-rc-init is an initialization tool for the s6-rc -system. It must be run at boot time, prior to any +system. It must be run as root, at boot time, prior to any invocation of the <a href="s6-rc.html">s6-rc</a> binary. </p> -<h2> Requirements </h2> - - <h2> Interface </h2> <pre> - s6-rc-init [ -v <em>verbosity</em> ] [ <em>servicenames...</em> ] + s6-rc-init [ -c <em>compiled</em> ] [ -l <em>live</em> ] [ -t <em>timeout</em> ] <em>scandir</em> </pre> <ul> - <li> s6-rc expects to find a <em>compiled service database</em> -in <tt>/etc/s6-rc/compiled</tt> and a <em>live state</em> in -<tt>/s6/s6-rc</tt>. If it cannot find that data, it complains and -exits. - <ul> - <li> The <em>compiled service database</em> is built offline -via the <a href="s6-rc-compile.html">s6-rc-compile</a> tool. </li> - <li> The <em>live state</em> should be initialized at boot time -via the <a href="s6-rc-init.html">s6-rc-init</a> tool. It is then -maintained by s6-rc itself. </li> - </ul> </li> - <li> The command line arguments <em>servicenames...</em> define a set -of selected services the user wants to act on. </li> - <li> s6-rc computes the necessary transitions to bring the machine -to the desired state - by default a state where all the -services listed on the command line are up. If asked to, it performs -those transitions. </li> - <li> s6-rc processes services as soon as they can be processed. It -will wait until a service is up to start a dependent service, but it -will start two independent services in parallel. </li> - <li> If every state transition completes successfully, s6-rc exits 0. </li> - <li> If a state transition fails, s6-rc will not perform the transitions -that depend on it. It will wait until all the other independent transitions -are done, then exit 1. </li> -</ul> + <li> <em>compiled</em>, <em>live</em> and <em>scandir</em> must be +absolute paths. </li> + <li> s6-rc-init expects to find a <em>compiled service database</em> +in <em>compiled</tt>. It expects to be able to create a directory +at <em>live</em>. It also expects that an instance of +<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> +is running on <em>scandir</em>. </li> + <li> s6-rc-init initializes the live state in <em>live</em>. It +declares <em>compiled</em> as the current service database and +sets the state as "all services down". </li> + <li> It then copies verbatim all +the service directories declared by <em>compiled</em> into a +subdirectory of <em>live</em>, adds down files to the live copies +and links them into <em>scandir</em>. It then triggers +<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a>, +which will pick up the new service directories and start +http://skarnet.org/software/s6/s6-supervise.html">s6-supervise</a> +processes on them - but the service themselves will not be started +right away, because of the down files. </li> + <li> s6-rc-init waits for all s6-supervise processes to be +operational, then exits 0. </li> <h2> Options </h2> -<h3> s6-rc control </h3> - -<ul> - <li> <tt>-v <em>verbosity</em></tt> : be more or less -verbose. Default is 1: warning and error messages will be printed to -stderr. 0 silences warnings. 2 writes information messages whenever -s6-rc performs a transition. 3 or more is debug info. </li> - <li> <tt>-n <em>dryruntimeout</em></tt> : dry run. -s6-rc will pretend to perform transitions, but will replace all its -program invocations by a call to -<a href="s6-rc-dryrun">s6-rc-dryrun</a>, which will do nothing but -print the command line s6-rc would have executed, then sleep for -<em>dryruntimeout</em> milliseconds before reporting success. </li> - <li> <tt>-t <em>timeout</em></tt> : timeout. If s6-rc -isn't done after <em>timeout</em> milliseconds, it will exit, leaving -the live state as it is at exit time. It does not kill its children, so -a child may successfully complete afterwards and the live state will -not be updated; in that case, subsequent s6-rc invocations will notice -and correctly update it. </li> - <li> <tt>-c <em>compiled</em></tt> : look for the -compiled service database in <em>compiled</em>. Default is -<tt>/etc/s6-rc/compiled</tt> </li> - <li> <tt>-l <em>live</em></tt> : look for the -live state in <em>live</em>. Default is -<tt>/s6/s6-rc</tt> </li> -</ul> - -<h3> Up or down </h3> - <ul> - <li> <tt>-u</tt> : selected services are interpreted -as to be brought <em>up</em>. This is the default. </li> - <li> <tt>-d</tt> : selected services are interpreted -as to be brought <em>down</em>. </li> + <li> <tt>-t <em>timeout</em></tt> : if all +s6-supervise processes are not up and running after <em>timeout</em> +milliseconds, s6-rc-init will complain and exit 111. This is a +safety feature so s6-rc-init doesn't hang indefinitely on a +nonworking installation; normally this initialization should not take +more than a few milliseconds. </li> + <li> <tt>-c <em>compiled</em></tt> : declare <em>compiled</em> +as the current compiled service database for the upcoming live state. +Default is <tt>/etc/s6-rc/compiled</tt>. </li> + <li> <tt>-l <em>live</em></tt> : Store the live state into +the <em>live</em> directory, which should not exist prior to running +s6-rc-init, but should be under a writable filesystem - likely a RAM +filesystem. Default is +<tt>/run/s6-rc</tt>. </li> </ul> -<h3> Service selection </h3> - -<ul> - <li> <tt>-p</tt> : prune. The state will be brought to -<em>exactly</em> <em>servicenames...</em>, plus their dependencies, and -the other services will be brought down. With the <tt>-d</tt> option, -the meaning is reversed: the state will be brought to the maximum -possible set that does not include <em>servicenames...</em>. </li> - <li> <tt>-a</tt> : all. Add the current set of active services to -the selected set. This is useful to ensure consistency of the machine -state, for instance, and also at shutdown time: <tt>s6-rc -da</tt> -will stop all the currently active services. </li> -</ul> +<h2> Typical usage </h2> -<h3> Actions </h3> - -<ul> - <li> <tt>-C</tt> : check. s6-rc will check the consistency of the -database, and exit with an error message if it finds errors. </li> - <li> <tt>-L</tt> : list. s6-rc will resolve the given names, then -print the list of corresponding atomic services to stdout, without taking their -dependencies into account. It will print an empty line afterwards. </li> - <li> <tt>-A</tt> : list all. s6-rc will print the list of selected -atomic services to stdout, after computing dependencies. Note that with -the <tt>-d</tt> option, it computes reverse dependencies instead. </li> - <li> <tt>-S</tt> : state change. A state change will be performed -for the selected services. -This is the default if no other action option has been given. </li> -</ul> - -<h2> Usage examples </h2> - -<pre> s6-rc <em>myservicebundle</em> </pre> <p> - Brings up all the services represented by <em>myservicebundle</em>, -dependencies first. + Administrators should invoke <tt>s6-rc-init</tt> once, in their +early boot scripts, after s6-svscan is functional but before any +other initialization. (The rest of the initialization can be +written as a set of s6-rc services, and performed by just one +invocation of the <a href="s6-rc.html">s6-rc change</a> command.) </p> -<pre> s6-rc -Sad </pre> <p> - Brings down all the services in an orderly manner. This is typically -run at shutdown time. + For instance, when using an init created by +<a href="http://skarnet.org/software/s6-linux-init/">s6-linux-init</a>, +<tt>s6-rc-init</tt> should be the first command in the +<em>stage2</em> (by default <tt>/etc/rc.init</tt>) script. </p> -<pre> s6-rc -Au <em>myservicebundle</em> </pre> -<p> - Prints the names of all atomic services represented by -<em>myservicebundle</em>, as well as everything they depend on. -</p> - -<pre> s6-rc -Ad <em>myservicebundle</em> </pre> -<p> - Prints the names of all atomic services represented by -<em>myservicebundle</em>, as well as everything that depends on them. -</p> - -<pre> s6-rc -pun0 <em>myservicebundle</em> </pre> -<p> - Prints what s6-rc would do to bring the state to just -<em>myservicebundle</em> and its dependencies. -</p> - - -<h2> Internals </h2> - </body> </html> |