socket-proxyd: rename from saproxy

The thing is a daemon, hence needs a "d" prefix. Also, we tend to not
abbreviate names of background components unnecessarily, since they are
not primary commands people type. Then, the fact that this thing does
socket actviation is mostly in implementationd detail for the proxy.

Also, do some minor indenting clean-ups and other code updates.

1 files changed, 254 insertions, 0 deletions

diff --git a/man/systemd-socket-proxyd.xml b/man/systemd-socket-proxyd.xml
new file mode 100644
index 0000000000..90b3b1c3a4
--- /dev/null
+++ b/man/systemd-socket-proxyd.xml
@@ -0,0 +1,254 @@
+<?xml version="1.0"?>
+<!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+     "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+  This file is part of systemd.
+
+  Copyright 2013 David Strauss
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+<refentry id="systemd-socket-proxyd">
+        <refentryinfo>
+                <title>systemd-socket-proxyd</title>
+                <productname>systemd</productname>
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>David</firstname>
+                                <surname>Strauss</surname>
+                                <email>david@davidstrauss.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+        <refmeta>
+                <refentrytitle>systemd-socket-proxyd</refentrytitle>
+                <manvolnum>1</manvolnum>
+        </refmeta>
+        <refnamediv>
+                <refname>systemd-socket-proxyd</refname>
+                <refpurpose>Inherit a socket. Bidirectionally
+                proxy.</refpurpose>
+        </refnamediv>
+        <refsynopsisdiv>
+                <cmdsynopsis>
+                        <command>systemd-socket-proxyd</command>
+                        <arg choice="opt" rep="repeat">OPTIONS</arg>
+                        <arg choice="plain"><replaceable>HOSTNAME-OR-IP</replaceable></arg>
+                        <arg choice="plain"><replaceable>PORT-OR-SERVICE</replaceable></arg>
+                </cmdsynopsis>
+                <cmdsynopsis>
+                        <command>systemd-socket-proxyd</command>
+                        <arg choice="opt" rep="repeat">OPTIONS</arg>
+                        <arg choice="plain"><replaceable>UNIX-DOMAIN-SOCKET-PATH</replaceable>
+                        </arg>
+                </cmdsynopsis>
+        </refsynopsisdiv>
+        <refsect1>
+                <title>Description</title>
+                <para>
+                <command>systemd-socket-proxyd</command> provides a proxy
+                to socket-activate services that do not yet support
+                native socket activation. On behalf of the daemon,
+                the proxy inherits the socket from systemd, accepts
+                each client connection, opens a connection to the server
+                for each client, and then bidirectionally forwards
+                data between the two.</para>
+                <para>This utility's behavior is similar to
+                <citerefentry><refentrytitle>socat</refentrytitle><manvolnum>1</manvolnum> </citerefentry>.
+                The main differences for <command>systemd-socket-proxyd</command>
+                are support for socket activation with
+                <literal>Accept=false</literal> and an event-driven
+                design that scales better with the number of
+                connections.</para>
+        </refsect1>
+        <refsect1>
+                <title>Options</title>
+                <para>The following options are understood:</para>
+                <variablelist>
+                        <varlistentry>
+                                <term><option>-h</option></term>
+                                <term><option>--help</option></term>
+                                <listitem>
+                                        <para>Prints a short help
+                                        text and exits.</para>
+                                </listitem>
+                        </varlistentry>
+                        <varlistentry>
+                                <term><option>--version</option></term>
+                                <listitem>
+                                        <para>Prints a version
+                                        string and exits.</para>
+                                </listitem>
+                        </varlistentry>
+                        <varlistentry>
+                                <term><option>--ignore-env</option></term>
+                                <listitem>
+                                        <para>Skips verification of
+                                        the expected PID and file
+                                        descriptor numbers. Use if
+                                        invoked indirectly, for
+                                        example with a shell script
+                                        rather than with
+                                        <option>ExecStart=/usr/bin/systemd-socket-proxyd</option>
+                                        </para>
+                                </listitem>
+                        </varlistentry>
+                </variablelist>
+        </refsect1>
+        <refsect1>
+                <title>Exit status</title>
+                <para>On success 0 is returned, a non-zero failure
+                code otherwise.</para>
+        </refsect1>
+        <refsect1>
+                <title>Examples</title>
+                <refsect2>
+                        <title>Direct-Use Example</title>
+                        <para>Use two services with a dependency
+                        and no namespace isolation.</para>
+                        <example label="proxy socket unit">
+                                <title>/etc/systemd/system/proxy-to-nginx.socket</title>
+                                <programlisting>
+<![CDATA[[Socket]
+ListenStream=80
+
+[Install]
+WantedBy=socket.target]]>
+</programlisting>
+                        </example>
+                        <example label="proxy service unit">
+                                <title>/etc/systemd/system/proxy-to-nginx.service</title>
+                                <programlisting>
+<![CDATA[[Unit]
+After=nginx.service
+Requires=nginx.service
+
+[Service]
+ExecStart=/usr/bin/systemd-socket-proxyd /tmp/nginx.sock
+PrivateTmp=true
+PrivateNetwork=true]]>
+</programlisting>
+                        </example>
+                        <example label="nginx configuration">
+                                <title>/etc/nginx/nginx.conf</title>
+                                <programlisting>
+<![CDATA[[...]
+server {
+    listen       unix:/tmp/nginx.sock;
+    [...]]]>
+</programlisting>
+                        </example>
+                        <example label="commands">
+                                <programlisting>
+<![CDATA[$ sudo systemctl --system daemon-reload
+$ sudo systemctl start proxy-to-nginx.socket
+$ sudo systemctl enable proxy-to-nginx.socket
+$ curl http://localhost:80/]]>
+</programlisting>
+                        </example>
+                </refsect2>
+                <refsect2>
+                        <title>Indirect-Use Example</title>
+                        <para>Use a shell script to isolate the
+                        service and proxy into the same namespace.
+                        This is particularly useful for running
+                        TCP-only daemons without the daemon
+                        affecting ports on regular
+                        interfaces.</para>
+                        <example label="combined proxy and nginx socket unit">
+
+                                <title>
+                                /etc/systemd/system/proxy-with-nginx.socket</title>
+                                <programlisting>
+<![CDATA[[Socket]
+ListenStream=80
+
+[Install]
+WantedBy=socket.target]]>
+</programlisting>
+                        </example>
+                        <example label="combined proxy and nginx service unit">
+
+                                <title>
+                                /etc/systemd/system/proxy-with-nginx.service</title>
+                                <programlisting>
+<![CDATA[[Unit]
+After=syslog.target remote-fs.target nss-lookup.target
+
+[Service]
+ExecStartPre=/usr/sbin/nginx -t
+ExecStart=/usr/bin/socket-proxyd-nginx.sh
+PrivateTmp=true
+PrivateNetwork=true]]>
+</programlisting>
+                        </example>
+                        <example label="shell script">
+                                <title>
+                                /usr/bin/socket-proxyd-nginx.sh</title>
+                                <programlisting>
+<![CDATA[#!/bin/sh
+/usr/sbin/nginx
+while [ ! -f /tmp/nginx.pid ]
+  do
+     /usr/bin/inotifywait /tmp/nginx.pid
+  done
+/usr/bin/systemd-socket-proxyd --ignore-env localhost 8080]]>
+</programlisting>
+                        </example>
+                        <example label="nginx configuration">
+                                <title>
+                                /etc/nginx/nginx.conf</title>
+                                <programlisting>
+<![CDATA[[...]
+server {
+    listen       8080;
+    listen       unix:/tmp/nginx.sock;
+    [...]]]>
+</programlisting>
+                        </example>
+                        <example label="commands">
+                                <programlisting>
+<![CDATA[$ sudo systemctl --system daemon-reload
+$ sudo systemctl start proxy-with-nginx.socket
+$ sudo systemctl enable proxy-with-nginx.socket
+$ curl http://localhost:80/]]>
+</programlisting>
+                        </example>
+                </refsect2>
+        </refsect1>
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                <citerefentry>
+                        <refentrytitle>
+                        systemd.service</refentrytitle>
+                        <manvolnum>5</manvolnum>
+                </citerefentry>,
+                <citerefentry>
+                        <refentrytitle>
+                        systemd.socket</refentrytitle>
+                        <manvolnum>5</manvolnum>
+                </citerefentry>,
+                <citerefentry>
+                        <refentrytitle>systemctl</refentrytitle>
+                        <manvolnum>1</manvolnum>
+                </citerefentry>,
+                <citerefentry>
+                        <refentrytitle>socat</refentrytitle>
+                        <manvolnum>1</manvolnum>
+                </citerefentry></para>
+        </refsect1>
+</refentry>