Date: Tue, 20 May 2008 21:21:29 GMT From: Remko Lodder <remko@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 141932 for review Message-ID: <200805202121.m4KLLTXa081420@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=141932 Change 141932 by remko@remko_guardian on 2008/05/20 21:21:19 Placeholder the jails chapter. Facilitated by: Snow B.V. Affected files ... .. //depot/projects/docproj_nl/nl_NL.ISO8859-1/books/handbook/jails/chapter.sgml#2 edit Differences ... ==== //depot/projects/docproj_nl/nl_NL.ISO8859-1/books/handbook/jails/chapter.sgml#2 (text+ko) ==== @@ -9,7 +9,7 @@ <author> <firstname>Matteo</firstname> <surname>Riondato</surname> - <contrib>Contributed by </contrib> + <contrib>Bijgedragen door </contrib> </author> </authorgroup> </chapterinfo> @@ -19,474 +19,57 @@ <indexterm><primary>jails</primary></indexterm> <sect1 id="jails-synopsis"> - <title>Synopsis</title> + <title>* Overzicht</title> - <para>This chapter will provide an explanation of what &os; jails - are and how to use them. Jails, sometimes referred to as an - enhanced replacement of <emphasis>chroot environments</emphasis>, - are a very powerful tool for system administrators, but their basic - usage can also be useful for advanced users.</para> - - <para>After reading this chapter, you will know:</para> - - <itemizedlist> - <listitem> - <para>What a jail is, and what purpose it may serve in &os; - installations.</para> - </listitem> - - <listitem> - <para>How to build, start, and stop a jail.</para> - </listitem> - - <listitem> - <para>The basics of jail administration, both from inside - and outside the jail.</para> - </listitem> - </itemizedlist> - - <para>Other sources of useful information about jails are:</para> - - <itemizedlist> - <listitem> - <para>The &man.jail.8; manual page. This is the full reference - of the <command>jail</command> utility — the - administrative tool which can be used in &os; to start, stop, - and control &os; jails.</para> - </listitem> - - <listitem> - <para>The mailing lists and their archives. The archives of the - &a.questions; and other mailing lists hosted by the - &a.mailman.lists; already contain a wealth of material for - jails. It should always be engaging to search the archives, - or post a new question to the &a.questions.name; mailing - list.</para> - </listitem> - </itemizedlist> - + <para>Wordt nog vertaald.</para> </sect1> <sect1 id="jails-terms"> - <title>Terms Related to Jails</title> + <title>* Termen gerelateerd aan jails</title> - <para>To facilitate better understanding of parts of the &os; system - related to jails, their internals and the way they interact with - the rest of &os;, the following terms are used further in this - chapter:</para> - - <variablelist> - <varlistentry> - <term>&man.chroot.2; (command)</term> - <listitem> - <para>A system call of &os;, which changes the root directory of a - process and all its descendants.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>&man.chroot.2; (environment)</term> - <listitem> - <para>The environment of processes running in - a <quote>chroot</quote>. This includes resources such as the part - of the file system which is visible, user and group IDs which are - available, network interfaces and other IPC mechanisms, - etc.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>&man.jail.8; (command)</term> - <listitem> - <para>The system administration utility which allows launching of - processes within a jail environment.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>host (system, process, user, etc.)</term> - <listitem> - <para>The controlling system of a jail environment. The host system - has access to all the hardware resources available, and can - control processes both outside of and inside a jail environment. - One of the important differences of the host system from a jail is - that the limitations which apply to superuser processes inside a - jail are not enforced for processes of the host system.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>hosted (system, process, user, etc.)</term> - <listitem> - <para>A process, user or other entity, whose access to resources is - restricted by an &os; jail.</para> - </listitem> - </varlistentry> - </variablelist> + <para>Wordt nog vertaald.</para> </sect1> <sect1 id="jails-intro"> - <title>Introduction</title> + <title>* Introductie</title> - <para>Since system administration is a difficult and perplexing - task, many powerful tools were developed to make life easier for - the administrator. These tools mostly provide enhancements of some sort - to the way systems are installed, configured and maintained. - Part of the tasks which an administrator is - expected to do is to properly configure the security of a system, - so that it can continue serving its real purpose, without allowing - security violations.</para> + <para>Wordt nog vertaald.</para> - <para>One of the tools which can be used to enhance the security of - a &os; system are <emphasis>jails</emphasis>. Jails were - introduced in &os; 4.X by &a.phk;, but were greatly improved in - &os; 5.X to make them a powerful and flexible subsystem. Their - development still goes on, enhancing their usefulness, performance, reliability, - and security.</para> - <sect2 id="jails-what"> - <title>What is a Jail</title> + <title>* Wat is een jail</title> - <para>BSD-like operating systems have had &man.chroot.2; since the - time of 4.2BSD. The &man.chroot.8; utility can be used to - change the root directory - of a set of processes, creating a safe environment, separate - from the rest of the system. Processes created in the chrooted - environment can not access files or resources outside of it. - For that reason, compromising a service running in a chrooted - environment should not allow the attacker to compromise the - entire system. The &man.chroot.8; utility is good for easy - tasks, which do not require a lot of flexibility or complex and - advanced features. Since the inception of the - chroot concept, however, many ways have been found to escape from a - chrooted environment and, although they have been fixed in - modern versions of the &os; kernel, it was clear that - &man.chroot.2; was not the ideal solution for securing services. - A new subsystem had to be implemented.</para> - - <para>This is one of the main reasons why - <emphasis>jails</emphasis> were developed.</para> - - <para>Jails improve on the concept of the traditional - &man.chroot.2; environment, in several ways. In a traditional - &man.chroot.2; environment, processes are only limited in the - part of the file system they can access. The rest of the system - resources (like the set of system users, the running processes, - or the networking subsystem) are shared by the chrooted - processes and the processes of the host system. Jails expand - this model by virtualizing not only access to the file system, - but also the set of users, the networking subsystem of the &os; - kernel and a few other things. A more complete set of - fine-grained controls available for tuning the access of a - jailed environment is described in <xref - linkend="jails-tuning">.</para> - - <para>A jail is characterized by four elements:</para> - - <itemizedlist> - <listitem> - <para>A directory subtree — the starting point from - which a jail is entered. Once inside the jail, a process - is not permitted to escape outside of this subtree. - Traditional security issues which plagued the original - &man.chroot.2; design will not affect &os; jails.</para> - </listitem> - - <listitem> - <para>A hostname — the hostname which will be used - within the jail. Jails are mainly used for hosting network - services, therefore having a descriptive hostname for each - jail can really help the system administrator.</para> - </listitem> - - <listitem> - <para>An <acronym>IP</acronym> address — this will be - assigned to the jail and cannot be changed in any way during - the jail's life span. The IP address of a jail is usually an alias address - for an existing network interface, but this is not strictly necessary.</para> - </listitem> - - <listitem> - <para>A command — the path name of an executable to run - inside the jail. This is relative to the root directory of - the jail environment, and may vary a lot, depending on the - type of the specific jail environment.</para> - </listitem> - </itemizedlist> - - <para>Apart from these, jails can have their own set of users and - their own <username>root</username> user. Naturally, the powers - of the <username>root</username> user are limited within the - jail environment and, from the point of view of the host system, - the jail <username>root</username> user is not an omnipotent user. - In addition, the <username>root</username> user of a jail is not - allowed to perform critical operations to the system outside of - the associated &man.jail.8; environment. More information - about capabilities and restrictions of the - <username>root</username> user will be discussed in <xref - linkend="jails-tuning"> below.</para> + <para>Wordt nog vertaald.</para> </sect2> </sect1> <sect1 id="jails-build"> - <title>Creating and Controlling Jails</title> + <title>* Creeëren en controleren van jails</title> - <para>Some administrators divide jails into the following two types: - <quote>complete</quote> jails, which resemble a real &os; system, - and <quote>service</quote> jails, dedicated to one application or - service, possibly running with privileges. This is only a - conceptual division and the process of building a jail is not - affected by it. The &man.jail.8; manual page is quite clear about - the procedure for building a jail:</para> - - <screen>&prompt.root; <userinput>setenv D <replaceable>/here/is/the/jail</replaceable></userinput> -&prompt.root; <userinput>mkdir -p $D</userinput> <co id="jailpath"> -&prompt.root; <userinput>cd /usr/src</userinput> -&prompt.root; <userinput>make world DESTDIR=$D</userinput> <co id="jailworld"> -&prompt.root; <userinput>cd etc/</userinput> <footnote><para>This step -is not required on &os; 6.0 and later.</para></footnote> -&prompt.root; <userinput>make distribution DESTDIR=$D</userinput> <co id="jaildistrib"> -&prompt.root; <userinput>mount -t devfs devfs $D/dev</userinput> <co id="jaildevfs"></screen> - - <calloutlist> - <callout arearefs="jailpath"> - <para>Selecting a location for a jail is the best starting point. - This is where the jail will physically reside within the file system of the jail's host. - A good choice can be <filename - role="directory">/usr/jail/<replaceable>jailname</replaceable></filename>, - where <replaceable>jailname</replaceable> is the hostname - identifying the jail. The <filename - role="directory">/usr/</filename> file system usually has - enough space for the jail file system, which for <quote>complete</quote> jails is, essentially, - a replication of every file present in a default installation - of the &os; base system.</para> - </callout> - - <callout arearefs="jailworld"> - <para>This command will populate the directory subtree chosen - as jail's physical location on the file system with the - necessary binaries, libraries, manual pages and so on. - Everything is done in the typical &os; style — first - everything is built/compiled, then installed to the - destination path.</para> - </callout> - - <callout arearefs="jaildistrib"> - <para>The <maketarget>distribution</maketarget> target for - <application>make</application> installs every needed - configuration file. In simple words, it installs every installable file of - <filename role="directory">/usr/src/etc/</filename> to the - <filename role="directory">/etc</filename> directory of the jail - environment: - <filename role="directory">$D/etc/</filename>.</para> - </callout> - - <callout arearefs="jaildevfs"> - <para>Mounting the &man.devfs.8; file system inside a jail is - not required. On the other hand, any, or almost any - application requires access to at least one device, depending - on the purpose of the given application. It is very important - to control access to devices from inside a jail, as improper - settings could permit an attacker to do nasty things in the - jail. Control over &man.devfs.8; is managed through rulesets - which are described in the &man.devfs.8; and - &man.devfs.conf.5; manual pages.</para> - </callout> - </calloutlist> - - <para>Once a jail is installed, it can be started by using the - &man.jail.8; utility. The &man.jail.8; utility takes four - mandatory arguments which are described in the <xref - linkend="jails-what">. Other arguments may be - specified too, e.g., to run the jailed process with the credentials of a specific - user. The <option><replaceable>command</replaceable></option> argument depends on - the type of the jail; for a <emphasis>virtual system</emphasis>, - <filename>/etc/rc</filename> is a good choice, since it will - replicate the startup sequence of a real &os; system. For a - <emphasis>service</emphasis> jail, it depends on the service or - application that will run within the jail.</para> - - <para>Jails are often started at boot time and the &os; - <filename>rc</filename> mechanism provides an easy way to do - this.</para> - - <procedure> - <step> - <para>A list of the jails which are enabled to start at boot - time should be added to the &man.rc.conf.5; file:</para> - - <programlisting>jail_enable="YES" # Set to NO to disable starting of any jails -jail_list="<replaceable>www</replaceable>" # Space separated list of names of jails</programlisting> - </step> - - <step> - <para>For each jail listed in <varname>jail_list</varname>, a - group of &man.rc.conf.5; settings, which describe the - particular jail, should be added:</para> - - <programlisting>jail_<replaceable>www</replaceable>_rootdir="/usr/jail/www" # jail's root directory -jail_<replaceable>www</replaceable>_hostname="<replaceable>www</replaceable>.example.org" # jail's hostname -jail_<replaceable>www</replaceable>_ip="192.168.0.10" # jail's IP address -jail_<replaceable>www</replaceable>_devfs_enable="YES" # mount devfs in the jail -jail_<replaceable>www</replaceable>_devfs_ruleset="<replaceable>www_ruleset</replaceable>" # devfs ruleset to apply to jail</programlisting> - - <para>The default startup of jails configured in - &man.rc.conf.5;, will run the <filename>/etc/rc</filename> - script of the jail, which assumes the jail is a complete - virtual system. For service jails, the default startup - command of the jail should be changed, by setting the - <varname>jail_<replaceable>jailname</replaceable>_exec_start</varname> - option appropriately.</para> - - <note> - <para>For a full list of available options, please see the - &man.rc.conf.5; manual page.</para> - </note> - </procedure> - - <para>The <filename>/etc/rc.d/jail</filename> script can be used to - start or stop a jail by hand, if an entry for it exists in - <filename>rc.conf</filename>:</para> - - <screen>&prompt.root; <userinput>/etc/rc.d/jail start <replaceable>www</replaceable></userinput> -&prompt.root; <userinput>/etc/rc.d/jail stop <replaceable>www</replaceable></userinput></screen> - - <para>A clean way to shut down a &man.jail.8; is not available at - the moment. This is because commands normally used to accomplish - a clean system shutdown cannot be used inside a jail. The best - way to shut down a jail is to run the following command from - within the jail itself or using the &man.jexec.8; utility from - outside the jail:</para> - - <screen>&prompt.root; <userinput>sh /etc/rc.shutdown</userinput></screen> - - <para>More information about this can be found in the &man.jail.8; - manual page.</para> + <para>Wordt nog vertaald.</para> </sect1> <sect1 id="jails-tuning"> - <title>Fine Tuning and Administration</title> + <title>* Optimaliseren en administratie</title> - <para>There are several options which can be set for any jail, and - various ways of combining a host &os; system with jails, to produce - higher level applications. This section presents:</para> + <para>Wordt nog vertaald.</para> - <itemizedlist> - <listitem> - <para>Some of the options available for tuning the behavior and - security restrictions implemented by a jail - installation.</para> - </listitem> - - <listitem> - <para>Some of the high-level applications for jail management, - which are available through the &os; Ports Collection, and can - be used to implement overall jail-based solutions.</para> - </itemizedlist> - <sect2 id="jails-tuning-utilities"> - <title>System tools for jail tuning in &os;</title> + <title>* Systeem applicaties voor het optimaliser van jails onder + &os;</title> - <para>Fine tuning of a jail's configuration is mostly done by - setting &man.sysctl.8; variables. A special subtree of sysctl - exists as a basis for organizing all the relevant options: the - <varname>security.jail.*</varname> hierarchy of &os; kernel - options. Here is a list of the main jail-related sysctls, - complete with their default value. Names should be - self-explanatory, but for more information about them, please - refer to the &man.jail.8; and &man.sysctl.8; manual - pages.</para> - - <itemizedlist> - <listitem> - <para><varname>security.jail.set_hostname_allowed: - 1</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.socket_unixiproute_only: - 1</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.sysvipc_allowed: - 0</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.enforce_statfs: - 2</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.allow_raw_sockets: - 0</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.chflags_allowed: - 0</varname></para> - </listitem> - - <listitem> - <para><varname>security.jail.jailed: 0</varname></para> - </listitem> - </itemizedlist> - - <para>These variables can be used by the system administrator of - the <emphasis>host system</emphasis> to add or remove some of - the limitations imposed by default on the - <username>root</username> user. Note that there are some - limitations which cannot be removed. The - <username>root</username> user is not allowed to mount or - unmount file systems from within a &man.jail.8;. The - <username>root</username> inside a jail may not load or unload - &man.devfs.8; rulesets, set firewall rules, or do many other - administrative tasks which require modifications of in-kernel - data, such as setting the <varname>securelevel</varname> of the - kernel.</para> - - <para>The base system of &os; contains a basic set of tools for - viewing information about the active jails, and attaching to a - jail to run administrative commands. The &man.jls.8; and - &man.jexec.8; commands are part of the base &os; system, and can be used - to perform the following simple tasks:</para> - - <itemizedlist> - <listitem> - <para>Print a list of active jails and their corresponding - jail identifier (<acronym>JID</acronym>), - <acronym>IP</acronym> address, hostname and path.</para> - </listitem> - - <listitem> - <para>Attach to a running jail, from its host system, and run - a command inside the jail or perform administrative tasks inside the - jail itself. This is especially useful when the - <username>root</username> user wants to cleanly shut down a - jail. The &man.jexec.8; utility can also be used to start a - shell in a jail to do administration in it; for - example:</para> - - <screen>&prompt.root; <userinput>jexec <replaceable>1</replaceable> tcsh</userinput></screen> - </listitem> - </itemizedlist> + <para>Wordt nog vertaald.</para> </sect2> <sect2 id="jails-tuning-admintools"> - <title>High-level administrative tools in &os; Ports - Collection</title> + <title>* High-Level administratieve applicaties in de &os; + Ports Collection.</title> - <para>Among the many third-party utilities for jail administration, - one of the most complete and useful is <filename - role="package">sysutils/jailutils</filename>. It is a set of - small applications that contribute to &man.jail.8; management. - Please refer to its web page for more information.</para> + <para>Wordt nog vertaald.</para> </sect2> </sect1> <sect1 id="jails-application"> - <title>Application of Jails</title> + <title>* Toepassing van jails</title> <sect2 id="jails-service-jails"> <sect2info> @@ -494,467 +77,38 @@ <author> <firstname>Daniel</firstname> <surname>Gerzo</surname> - <contrib>Contributed by </contrib> + <contrib>Bijgedragen door </contrib> <!-- 15. May 2007 --> </author> </authorgroup> </sect2info> - <title>Service Jails</title> + <title>* Dienst jails</title> - <para>This section is based upon an idea originally presented by - &a.simon; at <ulink - url="http://simon.nitro.dk/service-jails.html"></ulink>, and an - updated article written by Ken Tom - <email>locals@gmail.com</email>. This section illustrates how - to set up a &os; system that adds an additional layer of - security, using the &man.jail.8; feature. It is also assumed - that the given system is at least running RELENG_6_0 and the - information provided earlier in this chapter has been well - understood.</para> + <para>Wordt nog vertaald.</para> <sect3 id="jails-service-jails-design"> - <title>Design</title> + <title>* Ontwerp</title> - <para>One of the major problems with jails is the management of - their upgrade process. This tends to be a problem because - every jail has to be rebuilt from scratch whenever it is - updated. This is usually not a problem for a single jail, - since the update process is fairly simple, but can be quite - time consuming and tedious if a lot of jails are - created.</para> - - <warning> - <para>This setup requires advanced experience with &os; and - usage of its features. If the presented steps below look - too complicated, it is advised to take a look at a simpler - system such as <filename - role="package">sysutils/ezjail</filename>, which provides - an easier method of administering &os; jails and is not as - sophisticated as this setup.</para> - </warning> - - <para>This idea has been presented to resolve such issues by - sharing as much as is possible between jails, in a safe way - — using read-only &man.mount.nullfs.8; mounts, so that - updating will be be simpler, and putting single services into - individual jails will become more attractive. Additionally, - it provides a simple way to add or remove jails as well as a - way to upgrade them.</para> - - <note> - <para>Examples of services in this context are: an - <acronym>HTTP</acronym> server, a <acronym>DNS</acronym> - server, a <acronym>SMTP</acronym> server, and so forth.</para> - </note> - - <para>The goals of the setup described in this section - are:</para> - - <itemizedlist> - <listitem> - <para>Create a simple and easy to understand jail structure. - This implies <emphasis>not</emphasis> having to run a full - installworld on each and every jail.</para> - </listitem> - <listitem> - <para>Make it easy to add new jails or remove existing - ones.</para> - </listitem> - <listitem> - <para>Make it easy to update or upgrade existing - jails.</para> - </listitem> - <listitem> - <para>Make it possible to run a customized &os; - branch.</para> - </listitem> - <listitem> - <para>Be paranoid about security, reducing as much as - possible the possibility of compromise.</para> - </listitem> - <listitem> - <para>Save space and inodes, as much as possible.</para> - </listitem> - </itemizedlist> - - <para>As it has been already mentioned, this design relies - heavily on having a single master template which is read-only - (known as <application>nullfs</application>) mounted into each - jail and one read-write device per jail. A device can be a - separate physical disc, a partition, or a vnode backed - &man.md.4; device. In this example, we will use read-write - <application>nullfs</application> mounts.</para> - - <para>The file system layout is described in the following - list:</para> - - <itemizedlist> - <listitem> - <para>Each jail will be mounted under the <filename - role="directory">/home/j</filename> directory.</para> - </listitem> - <listitem> - <para><filename role="directory">/home/j/mroot</filename> is - the template for each jail and the read-only partition for - all of the jails.</para> - </listitem> - <listitem> - <para>A blank directory will be created for each jail under - the <filename role="directory">/home/j</filename> - directory.</para> - </listitem> - <listitem> - <para>Each jail will have a <filename - role="directory">/s</filename> directory, that will be - linked to the read-write portion of the system.</para> - </listitem> - <listitem> - <para>Each jail shall have its own read-write system that is - based upon <filename - role="directory">/home/j/skel</filename>.</para> - </listitem> - <listitem> - <para>Each jailspace (read-write portion of each jail) shall - be created in <filename - role="directory">/home/js</filename>.<para> - </listitem> - </itemizedlist> - - <note> - <para>This assumes that the jails are based under the - <filename role="directory">/home</filename> partition. This - can, of course, be changed to anything else, but this change - will have to be reflected in each of the examples - below.</para> - </note> - <!-- Insert an image or drawing here to illustrate the example. --> + <para>Wordt nog vertaald.</para> </sect3> <sect3 id="jails-service-jails-template"> - <title>Creating the Template</title> + <title>* De template creeëren</title> - <para>This section will describe the steps needed to create the - master template that will be the read-only portion for the - jails to use.<para> - - <para>It is always a good idea to update the &os; system to the - latest -RELEASE branch. Check the corresponding Handbook - <ulink url="&url.books.handbook;/makeworld.html">Chapter</ulink> - to accomplish this task. In the case the update is not - feasible, the buildworld will be required in order to be able - to proceed. Additionally, the <filename - role="package">sysutils/cpdup</filename> package will be - required. We will use the &man.portsnap.8; utility to - download the &os; Ports Collection. The Handbook <ulink - url="&url.books.handbook;/portsnap.html">Portsnap Chapter</ulink> - is always good reading for newcomers.</para> - - <procedure> - <step> - <para>First, create a directory structure for the read-only - file system which will contain the &os; binaries for our - jails, then change directory to the &os; source tree and - install the read-only file system to the jail - template:</para> - - <screen>&prompt.root; <userinput>mkdir /home/j /home/j/mroot</userinput> -&prompt.root; <userinput>cd /usr/src</userinput> -&prompt.root; <userinput>make installworld DESTDIR=/home/j/mroot</userinput></screen> - </step> - <step> - <para>Next, prepare a &os; Ports Collection for the jails as - well as a &os; source tree, which is required for - <application>mergemaster</application>:</para> - - <screen>&prompt.root; <userinput>cd /home/j/mroot</userinput> -&prompt.root; <userinput>mkdir usr/ports</userinput> -&prompt.root; <userinput>portsnap -p /home/j/mroot/usr/ports fetch extract</userinput> -&prompt.root; <userinput>cpdup /usr/src /home/j/mroot/usr/src</userinput></screen> - </step> - <step> - <para>Create a skeleton for the read-write portion of the - system:</para> - - <screen>&prompt.root; <userinput>mkdir /home/j/skel /home/j/skel/home /home/j/skel/usr-X11R6 /home/j/skel/distfiles</userinput> -&prompt.root; <userinput>mv etc /home/j/skel</userinput> -&prompt.root; <userinput>mv usr/local /home/j/skel/usr-local</userinput> -&prompt.root; <userinput>mv tmp /home/j/skel</userinput> -&prompt.root; <userinput>mv var /home/j/skel</userinput> -&prompt.root; <userinput>mv root /home/j/skel</userinput></screen> - </step> - <step> - <para>Use <application>mergemaster</application> to install - missing configuration files. Then get rid of the extra - directories that <application>mergemaster</application> - creates:</para> - - <screen>&prompt.root; <userinput>mergemaster -t /home/j/skel/var/tmp/temproot -D /home/j/skel -i</userinput> -&prompt.root; <userinput>cd /home/j/skel</userinput> -&prompt.root; <userinput>rm -R bin boot lib libexec mnt proc rescue sbin sys usr dev</userinput></screen> - </step> - <step> - <para>Now, symlink the read-write file system to the - read-only file system. Please make sure that the symlinks - are created in the correct <filename - role="directory">s/</filename> locations. Real - directories or the creation of directories in the wrong - locations will cause the installation to fail.</para> - - <screen>&prompt.root; <userinput>cd /home/j/mroot</userinput> -&prompt.root; <userinput>mkdir s</userinput> -&prompt.root; <userinput>ln -s s/etc etc</userinput> -&prompt.root; <userinput>ln -s s/home home</userinput> -&prompt.root; <userinput>ln -s s/root root</userinput> -&prompt.root; <userinput>ln -s ../s/usr-local usr/local</userinput> -&prompt.root; <userinput>ln -s ../s/usr-X11R6 usr/X11R6</userinput> -&prompt.root; <userinput>ln -s ../../s/distfiles usr/ports/distfiles</userinput> -&prompt.root; <userinput>ln -s s/tmp tmp</userinput> -&prompt.root; <userinput>ln -s s/var var</userinput></screen> - </step> - <step> - <para>As a last step, create a generic - <filename>/home/j/skel/etc/make.conf</filename> with its - contents as shown below:</para> - - <programlisting>WRKDIRPREFIX?= /s/portbuild</programlisting> - - - <para>Having <literal>WRKDIRPREFIX</literal> set up this - way will make it possible to compile &os; ports inside - each jail. Remember that the ports directory is part of - the read-only system. The custom path for - <literal>WRKDIRPREFIX</literal> allows builds to be done - in the read-write portion of every jail.</para> - </step> - </procedure> + <para>Wordt nog vertaald.</para> </sect3> <sect3 id="jails-service-jails-creating"> - <title>Creating Jails</title> + <title>* Jails creeëren</title> - <para>Now that we have a complete &os; jail template, we can - setup and configure the jails in - <filename>/etc/rc.conf</filename>. This example demonstrates - the creation of 3 jails: <quote>NS</quote>, - <quote>MAIL</quote> and <quote>WWW</quote>.<para> - - <procedure> - <step> - <para>Put the following lines into the - <filename>/etc/fstab</filename> file, so that the - read-only template for the jails and the read-write space - will be available in the respective jails:</para> - - <programlisting>/home/j/mroot /home/j/ns nullfs ro 0 0 -/home/j/mroot /home/j/mail nullfs ro 0 0 -/home/j/mroot /home/j/www nullfs ro 0 0 -/home/js/ns /home/j/ns/s nullfs rw 0 0 -/home/js/mail /home/j/mail/s nullfs rw 0 0 -/home/js/www /home/j/www/s nullfs rw 0 0</programlisting> - - <note> - <para>Partitions marked with a 0 pass number are not - checked by &man.fsck.8; during boot, and partitions - marked with a 0 dump number are not backed up by - &man.dump.8;. We do not want - <application>fsck</application> to check - <application>nullfs</application> mounts or - <application>dump</application> to back up the read-only - nullfs mounts of the jails. This is why they are marked - with <quote>0 0</quote> in the last two columns of - each <filename>fstab</filename> entry above.</para> - </note> - </step> - <step> - <para>Configure the jails in - <filename>/etc/rc.conf</filename>:</para> - - <programlisting>jail_enable="YES" -jail_set_hostname_allow="NO" -jail_list="ns mail www" -jail_ns_hostname="ns.example.org" -jail_ns_ip="192.168.3.17" -jail_ns_rootdir="/usr/home/j/ns" -jail_ns_devfs_enable="YES" -jail_mail_hostname="mail.example.org" -jail_mail_ip="192.168.3.18" -jail_mail_rootdir="/usr/home/j/mail" -jail_mail_devfs_enable="YES" -jail_www_hostname="www.example.org" -jail_www_ip="62.123.43.14" -jail_www_rootdir="/usr/home/j/www" -jail_www_devfs_enable="YES"</programlisting> - - <warning> - <para>The reason why the - <varname>jail_<replaceable>name</replaceable>_rootdir</varname> - variable is set to <filename - role="directory">/usr/home</filename> instead of - <filename role="directory">/home</filename> is that the - physical path of the <filename - role="directory">/home</filename> directory on a - default &os; installation is <filename - role="directory">/usr/home</filename>. The - <varname>jail_<replaceable>name</replaceable>_rootdir</varname> - variable must <emphasis>not</emphasis> be set to a path - which includes a symbolic link, otherwise the jails will - refuse to start. Use the &man.realpath.1; utility to - determine a value which should be set to this variable. - Please see the &os;-SA-07:01.jail Security Advisory for - more information.</para> - </warning> - </step> - <step> - <para>Create the required mount points for the read-only - file system of each jail:</para> - - <screen>&prompt.root; <userinput>mkdir /home/j/ns /home/j/mail /home/j/www</userinput></screen> - </step> - <step> - <para>Install the read-write template into each jail. Note - the use of <filename - role="package">sysutils/cpdup</filename>, which helps to - ensure that a correct copy is done of each - directory:</para> - <!-- keramida: Why is cpdup required here? Doesn't cpio(1) - already include adequate functionality for performing this - job *and* have the advantage of being part of the base - system of FreeBSD? --> - - <screen>&prompt.root; <userinput>mkdir /home/js</userinput> -&prompt.root; <userinput>cpdup /home/j/skel /home/js/ns</userinput> -&prompt.root; <userinput>cpdup /home/j/skel /home/js/mail</userinput> -&prompt.root; <userinput>cpdup /home/j/skel /home/js/www</userinput></screen> - </step> - <step> - <para>In this phase, the jails are built and prepared to - run. First, mount the required file systems for each - jail, and then start them using the - <filename>/etc/rc.d/jail</filename> script:</para> - - <screen>&prompt.root; <userinput>mount -a</userinput> -&prompt.root; <userinput>/etc/rc.d/jail start</userinput></screen> - </step> - </procedure> - - <para>The jails should be running now. To check if they have - started correctly, use the &man.jls.8; command. Its output - should be similar to the following:</para> - - <screen>&prompt.root; <userinput>jls</userinput> - JID IP Address Hostname Path - 3 192.168.3.17 ns.example.org /home/j/ns - 2 192.168.3.18 mail.example.org /home/j/mail - 1 62.123.43.14 www.example.org /home/j/www</screen> - - <para>At this point, it should be possible to log onto each - jail, add new users or configure daemons. The - <literal>JID</literal> column indicates the jail - identification number of each running jail. Use the - following command in order to perform administrative tasks in - the jail whose <literal>JID</literal> is 3:</para> - - <screen>&prompt.root; <userinput>jexec 3 tcsh</userinput></screen> + <para>Wordt nog vertaald.</para> </sect3> <sect3 id="jails-service-jails-upgrading"> - <title>Upgrading</title> + <title>* Upgraden</title> - <para>In time, there will be a need to upgrade the system to a - newer version of &os;, either because of a security issue, or - because new features have been implemented which are useful - for the existing jails. The design of this setup provides an - easy way to upgrade existing jails. Additionally, it - minimizes their downtime, as the jails will be brought down - only in the very last minute. Also, it provides a way to roll - back to the older versions should any problems occur.</para> - - <procedure> - <step> - <para>The first step is to upgrade the host system in the - usual manner. Then create a new temporary read-only - template in <filename - role="directory">/home/j/mroot2</filename>.</para> - - <screen>&prompt.root; <userinput>mkdir /home/j/mroot2</userinput> -&prompt.root; <userinput>cd /usr/src</userinput> -&prompt.root; <userinput>make installworld DESTDIR=/home/j/mroot2</userinput> -&prompt.root; <userinput>cd /home/j/mroot2</userinput> -&prompt.root; <userinput>cpdup /usr/src usr/src</userinput> -&prompt.root; <userinput>mkdir s</userinput></screen> - - <para>The <maketarget>installworld</maketarget> run creates - a few unnecessary directories, which should be - removed:</para> - - <screen>&prompt.root; <userinput>chflags -R 0 var</userinput> -&prompt.root; <userinput>rm -R etc var root usr/local tmp</userinput></screen> - </step> - <step> - <para>Recreate the read-write symlinks for the master file - system:</para> - - <screen>&prompt.root; <userinput>ln -s s/etc etc</userinput> -&prompt.root; <userinput>ln -s s/root root</userinput> -&prompt.root; <userinput>ln -s s/home home</userinput> -&prompt.root; <userinput>ln -s ../s/usr-local usr/local</userinput> -&prompt.root; <userinput>ln -s ../s/usr-X11R6 usr/X11R6</userinput> -&prompt.root; <userinput>ln -s s/tmp tmp</userinput> -&prompt.root; <userinput>ln -s s/var var</userinput></screen> - </step> - <step> - <para>The right time to stop the jails is now:</para> - - <screen>&prompt.root; <userinput>/etc/rc.d/jail stop</userinput></screen> - </step> - <step> - <para>Unmount the original file systems:</para> - <!-- keramida: Shouldn't we suggest a short script-based - loop here, instead of tediously copying the same commands - multiple times? --> - - <screen>&prompt.root; <userinput>umount /home/j/ns/s</userinput> -&prompt.root; <userinput>umount /home/j/ns</userinput> -&prompt.root; <userinput>umount /home/j/mail/s</userinput> -&prompt.root; <userinput>umount /home/j/mail</userinput> -&prompt.root; <userinput>umount /home/j/www/s</userinput> -&prompt.root; <userinput>umount /home/j/www</userinput></screen> - - <note> - <para>The read-write systems are attached to the read-only - system (<filename role="directory">/s</filename>) and - must be unmounted first.</para> - </note> - </step> - <step> - <para>Move the old read-only file system and replace it with - the new one. This will serve as a backup and archive of the - old read-only file system should something go wrong. The - naming convention used here corresponds to when a new - read-only file system has been created. Move the original - &os; Ports Collection over to the new file system to save - some space and inodes:</para> - - <screen>&prompt.root; <userinput>cd /home/j</userinput> -&prompt.root; <userinput>mv mroot mroot.20060601</userinput> -&prompt.root; <userinput>mv mroot2 mroot</userinput> -&prompt.root; <userinput>mv mroot.20060601/usr/ports mroot/usr</userinput></screen> - </step> - <step> - <para>At this point the new read-only template is ready, so - the only remaining task is to remount the file systems and - start the jails:</para> - - <screen>&prompt.root; <userinput>mount -a</userinput> -&prompt.root; <userinput>/etc/rc.d/jail start</userinput></screen> - </step> - </procedure> - - <para>Use &man.jls.8; to check if the jails started correctly. - Do not forget to run mergemaster in each jail. The - configuration files will need to be updated as well as the - rc.d scripts.</para> + <para>Wordt nog vertaald.</para> </sect3> </sect2> </sect1>
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