diff options
Diffstat (limited to 'doc/s6-linux-init-maker.html')
| -rw-r--r-- | doc/s6-linux-init-maker.html | 60 |
1 files changed, 30 insertions, 30 deletions
diff --git a/doc/s6-linux-init-maker.html b/doc/s6-linux-init-maker.html index 1960563..b7648ed 100644 --- a/doc/s6-linux-init-maker.html +++ b/doc/s6-linux-init-maker.html @@ -6,14 +6,14 @@ <title>s6-linux-init: the s6-linux-init-maker program</title> <meta name="Description" content="s6-linux-init: the s6-linux-init-maker program" /> <meta name="Keywords" content="s6 linux administration root init maker" /> - <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> --> </head> <body> <p> <a href="index.html">s6-linux-init</a><br /> -<a href="http://skarnet.org/software/">Software</a><br /> -<a href="http://skarnet.org/">skarnet.org</a> +<a href="//skarnet.org/software/">Software</a><br /> +<a href="//skarnet.org/">skarnet.org</a> </p> <h1> The <tt>s6-linux-init-maker</tt> program </h1> @@ -24,7 +24,7 @@ the command line, and outputs a directory to place in the root filesystem. That directory contains a script suitable as an init program, as well as support file hierarchies to get a complete -<a href="http://skarnet.org/software/s6/">s6</a> +<a href="//skarnet.org/software/s6/">s6</a> infrastructure running when the system is booted on that script. </p> @@ -33,8 +33,8 @@ script. s6-linux-init-maker only writes scripts. At boot time, these scripts will call commands provided by other skarnet.org packages such as -<a href="http://skarnet.org/software/execline/">execline</a> or -<a href="http://skarnet.org/software/s6/">s6</a>. It is the +<a href="//skarnet.org/software/execline/">execline</a> or +<a href="//skarnet.org/software/s6/">s6</a>. It is the responsibility of the administrator to make sure that all the dependencies are properly installed at boot time, and that the correct options have been given to s6-linux-init-maker so that @@ -81,7 +81,7 @@ or its contents. </li> declared as <em>basedir</em>. Be careful: it contains fifos, files with precise uid/gid permissions, and files with non-standard access rights, so be sure to copy it verbatim. The -<a href="http://skarnet.org/software/s6-portable-utils/s6-hiercopy.html">s6-hiercopy</a> +<a href="//skarnet.org/software/s6-portable-utils/s6-hiercopy.html">s6-hiercopy</a> tool can do it, as well as the GNU or busybox <tt>cp -a</tt> or <tt>mv</tt> commands. </p> @@ -102,9 +102,9 @@ also known as <em>stage 1</em>. and this is what happens: <ul> <li> <em>stage 1</em> is an -<a href="http://skarnet.org/software/execline/">execline</a> script, so +<a href="//skarnet.org/software/execline/">execline</a> script, so the first process run by the kernel is the -<a href="http://skarnet.org/software/execline/execlineb.html">execlineb</a> +<a href="//skarnet.org/software/execline/execlineb.html">execlineb</a> program launcher. </li> <li> <em>stage 1</em> mounts a <a href="https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt">tmpfs</a> @@ -113,17 +113,17 @@ filesystem on <em>tmpfsdir</em>. </li> <em>tmpfsdir</em>. </li> <li> <em>stage 1</em> empties its environment, then reads a global set of environment variables from the <tt><em>basedir</em>/env</tt> -<a href="http://skarnet.org/software/s6/s6-envdir.html">environment directory</a>. </li> +<a href="//skarnet.org/software/s6/s6-envdir.html">environment directory</a>. </li> <li> <em>stage 1</em> forks a child that will block until -<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> is running. </li> +<a href="//skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> is running. </li> <li> <em>stage 1</em> executes, as process 1, into -<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a>, +<a href="//skarnet.org/software/s6/s6-svscan.html">s6-svscan</a>, with <tt><em>tmpfsdir</em>/service</tt> as a -<a href="http://skarnet.org/software/s6/scandir.html">scan directory</a>. </li> +<a href="//skarnet.org/software/s6/scandir.html">scan directory</a>. </li> <li> This scan directory already contains at least one service, which is the <em>catch-all logger</em>: error messages from the supervision tree, and from services that do not have a dedicated logger, are handled by a -special <a href="http://skarnet.org/software/s6/s6-log.html">s6-log</a> +special <a href="//skarnet.org/software/s6/s6-log.html">s6-log</a> instance and made available in <tt><em>tmpfsdir</em>/uncaught-logs</tt> instead of clogging the system console. </li> <li> If the <tt>-G</tt> option has been given to s6-linux-init-maker, the @@ -150,10 +150,10 @@ to the catch-all logger, depending on the <tt>-r</tt> option. </li> <li> Depending on the kernel boot command line, the root filesystem may be in read-only mode. </li> <li> There is a tmpfs available for root only in <em>tmpfsdir</em>. </li> - <li> <a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> + <li> <a href="//skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> is running as process 1. At any time, it is possible to make it supervise a long-lived process by linking the appropriate -<a href="http://skarnet.org/software/s6/servicedir.html">service directory</a> +<a href="//skarnet.org/software/s6/servicedir.html">service directory</a> into <tt><em>tmpfsdir</em>/service</tt>, then running the command <tt>s6-svscanctl -a <em>tmpfsdir</em>/service</tt>. Services without a dedicated logger will send their output to the catch-all logger. </li> @@ -181,7 +181,7 @@ real machine and service initialization should happen in <em>stage2</em>. <a href="s6-reboot.html">s6-reboot</a> commands. </li> <li> Those commands send a signal to the -<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> +<a href="//skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> process running as pid 1; this signal is caught and s6-svscan runs the corresponding "signal handler" script that has been placed by s6-linux-init-maker into the @@ -194,13 +194,13 @@ must have been written by the administrator. The purpose of while the supervision tree is still alive. Typically, when using a service manager, <em>stage2_finish</em> would tell the service manager to bring all services down. When using -<a href="http://skarnet.org/software/s6-rc/">s6-rc</a>, a typical +<a href="//skarnet.org/software/s6-rc/">s6-rc</a>, a typical <em>stage2_finish</em> script just contains <tt>s6-rc -da change</tt>. More generally speaking, <em>stage2_finish</em> should undo what <em>stage2</em> has done at boot time. </li> <li> The "signal handler" script then tells s6-svscan to exit via an -appropriate <a href="http://skarnet.org/software/s6/s6-svscanctl.html">s6-svscanctl</a> +appropriate <a href="//skarnet.org/software/s6/s6-svscanctl.html">s6-svscanctl</a> command: s6-svscan then executes into the <em>stage3</em> script, which, like <em>stage2</em> and <em>stage2_finish</em>, is the responsibility of the administrator. When <em>stage3</em> runs, the machine is in the following @@ -209,11 +209,11 @@ state: <ul> <li> The supervision tree has been torn down: it is not operational anymore. (So, commands such as -<a href="http://skarnet.org/software/s6-rc/s6-rc.html">s6-rc</a>, which +<a href="//skarnet.org/software/s6-rc/s6-rc.html">s6-rc</a>, which require a live supervision tree, will not work.) <li> <em>stage3</em> runs as process 1. Doing so makes it easier to recover after killing all processes by <tt>kill -9 -1</tt> or -<a href="http://skarnet.org/software/s6-portable-utils/s6-nuke.html">s6-nuke</a>. </li> +<a href="//skarnet.org/software/s6-portable-utils/s6-nuke.html">s6-nuke</a>. </li> <li> Its working directory is <tt>/</tt> and its stdin is <tt>/dev/null</tt> </li> <li> Its stdout and stderr are both <tt>/dev/console</tt> </li> <li> Depending on the exact configuration and what the administrator has @@ -237,7 +237,7 @@ contains an example of <tt>/etc/rc.init</tt>, <tt>/etc/rc.tini</tt> and <tt>/etc/rc.shutdown</tt> scripts, suitable for <em>stage2</em>, <em>stage2_finish</em> and <em>stage3</em> respectively. Those scripts can practically be used as is if the machine -is managed by the <a href="http://skarnet.org/software/s6-rc/">s6-rc</a> +is managed by the <a href="//skarnet.org/software/s6-rc/">s6-rc</a> service manager. </p> @@ -260,7 +260,7 @@ the root filesystem, and be empty. <em>tmpfsdir</em> must be absolute. Default i <li> <tt>-b</tt> <em>execline_bindir</em> : init is run by the kernel without a PATH, and since it is a script, it is necessary to tell it where to find the -<a href="http://skarnet.org/software/execline/execlineb.html">execlineb</a> +<a href="//skarnet.org/software/execline/execlineb.html">execlineb</a> launcher and the first few early commands before PATH can be set. <em>execline_bindir</em> is the location where the execline binaries can be found. It must be absolute. Default is @@ -323,10 +323,10 @@ It must be absolute. Default is set the PATH environment variable to, for all the starting processes. This will be done as early as possible in <em>stage 1</em>. It is absolutely necessary for -<a href="http://skarnet.org/software/execline/">execline</a>, -<a href="http://skarnet.org/software/s6/">s6</a>, -<a href="http://skarnet.org/software/s6-portable-utils/">s6-portable-utils</a> and -<a href="http://skarnet.org/software/s6-linux-utils/">s6-linux-utils</a> +<a href="//skarnet.org/software/execline/">execline</a>, +<a href="//skarnet.org/software/s6/">s6</a>, +<a href="//skarnet.org/software/s6-portable-utils/">s6-portable-utils</a> and +<a href="//skarnet.org/software/s6-linux-utils/">s6-linux-utils</a> binaries to be accessible via <em>initial_path</em>, else the machine will not boot. Default is <strong><tt>/usr/bin:/bin</tt></strong>. </li> <p /> @@ -359,7 +359,7 @@ into the whole process tree. However, sometimes those variables are needed at a later time; in that case, giving the <tt>-s</tt> option to s6-linux-init-maker makes stage 1 init dump the "kernel" environment variables into the <em>env_store</em> directory, via the -<a href="http://skarnet.org/software/s6-portable-utils/s6-dumpenv.html">s6-dumpenv</a> +<a href="//skarnet.org/software/s6-portable-utils/s6-dumpenv.html">s6-dumpenv</a> program, before erasing them. <em>env_store</em> should obviously be a writable directory, so it should be located under <em>tmpfsdir</em>! If this option is not given (which is the default), the environment @@ -380,7 +380,7 @@ the global environment. </li> <p /> <p> The difficult parts of -<a href="http://skarnet.org/software/s6/s6-svscan-1.html">running +<a href="//skarnet.org/software/s6/s6-svscan-1.html">running s6-svscan as process 1</a> are: </p> @@ -404,7 +404,7 @@ virtual machine, a container, or anything similar that does not have the <tt>/dev/console</tt> issue or the read-only rootfs issue, you will probably not reap much benefit from using s6-linux-init-maker: you could probably invoke -<a href="http://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> +<a href="//skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> directly as your process 1, or build a script by hand, which would result in a simpler init with less dependencies. </p> |