Date: Tue, 25 Jun 2013 14:37:57 +0000 (UTC) From: Warren Block <wblock@FreeBSD.org> To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r42036 - head/en_US.ISO8859-1/books/handbook/jails Message-ID: <201306251437.r5PEbv73034886@svn.freebsd.org>
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Author: wblock Date: Tue Jun 25 14:37:56 2013 New Revision: 42036 URL: http://svnweb.freebsd.org/changeset/doc/42036 Log: Whitespace-only fixes. Translators, please ignore. Modified: head/en_US.ISO8859-1/books/handbook/jails/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/jails/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/jails/chapter.xml Tue Jun 25 02:50:16 2013 (r42035) +++ head/en_US.ISO8859-1/books/handbook/jails/chapter.xml Tue Jun 25 14:37:56 2013 (r42036) @@ -24,9 +24,10 @@ <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> + 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> <important> <para>Jails are a powerful tool, but they are not a security @@ -66,77 +67,79 @@ <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> + <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 + <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> - </sect1> <sect1 id="jails-terms"> <title>Terms Related to 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> + <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.8; (command)</term> - <listitem> - <para>Utility, which uses &man.chroot.2; &os; system call to change - the root directory of a process and all its descendants.</para> + <term>&man.chroot.8; (command)</term> + <listitem> + <para>Utility, which uses &man.chroot.2; &os; system call to + change 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> + <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> + <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> + <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 a &os; jail.</para> + <term>hosted (system, process, user, etc.)</term> + <listitem> + <para>A process, user or other entity, whose access to + resources is restricted by a &os; jail.</para> </listitem> </varlistentry> </variablelist> @@ -147,39 +150,39 @@ <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>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> + 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>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> - <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 much flexibility or complex, - 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>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 much flexibility or complex, 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> @@ -187,16 +190,16 @@ <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> + 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> @@ -211,51 +214,54 @@ <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> + 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> + 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. The path name is relative to the root directory of - the jail environment.</para> + <para>A command — the path name of an executable to + run inside the jail. The path name is relative to the + root directory of the 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>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> </sect2> </sect1> <sect1 id="jails-build"> <title>Creating and Controlling 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> + <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> + <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 buildworld</userinput> <co id="jailbuildworld"/> @@ -265,61 +271,67 @@ <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 + <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 class="directory">/usr/jail/<replaceable>jailname</replaceable></filename>, where <replaceable>jailname</replaceable> is the hostname - identifying the jail. The <filename - class="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> + identifying the jail. The + <filename class="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="jailbuildworld"> <para>If you have already rebuilt your userland using - <command>make world</command> or <command>make buildworld</command>, - you can skip this step and install your existing userland into the - new jail.</para> + <command>make world</command> or + <command>make buildworld</command>, you can skip this step + and install your existing userland into the new jail.</para> </callout> <callout arearefs="jailinstallworld"> <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.</para> + necessary binaries, libraries, manual pages and so + on.</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 + configuration file. In simple words, it installs every + installable file of <filename class="directory">/usr/src/etc/</filename> to the - <filename class="directory">/etc</filename> directory of the jail - environment: + <filename class="directory">/etc</filename> directory of the + jail environment: <filename class="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> + 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>, + &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 @@ -377,11 +389,11 @@ jail_<replaceable>www</replaceable>_devf &prompt.root; <userinput>service 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> + 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> @@ -393,20 +405,22 @@ jail_<replaceable>www</replaceable>_devf <title>Fine Tuning and Administration</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> + various ways of combining a host &os; system with jails, to + produce higher level applications. This section + presents:</para> <itemizedlist> <listitem> - <para>Some of the options available for tuning the behavior and - security restrictions implemented by a jail + <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> + which are available through the &os; Ports Collection, and + can be used to implement overall jail-based + solutions.</para> </listitem> </itemizedlist> @@ -426,32 +440,32 @@ jail_<replaceable>www</replaceable>_devf <itemizedlist> <listitem> <para><varname>security.jail.set_hostname_allowed: - 1</varname></para> + 1</varname></para> </listitem> <listitem> <para><varname>security.jail.socket_unixiproute_only: - 1</varname></para> + 1</varname></para> </listitem> <listitem> <para><varname>security.jail.sysvipc_allowed: - 0</varname></para> + 0</varname></para> </listitem> <listitem> <para><varname>security.jail.enforce_statfs: - 2</varname></para> + 2</varname></para> </listitem> <listitem> <para><varname>security.jail.allow_raw_sockets: - 0</varname></para> + 0</varname></para> </listitem> <listitem> <para><varname>security.jail.chflags_allowed: - 0</varname></para> + 0</varname></para> </listitem> <listitem> @@ -469,14 +483,14 @@ jail_<replaceable>www</replaceable>_devf <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> + 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> + &man.jexec.8; commands are part of the base &os; system, and + can be used to perform the following simple tasks:</para> <itemizedlist> <listitem> @@ -486,13 +500,13 @@ jail_<replaceable>www</replaceable>_devf </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> + <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> @@ -503,11 +517,12 @@ jail_<replaceable>www</replaceable>_devf <title>High-Level Administrative Tools in the &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>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> </sect2> </sect1> @@ -530,8 +545,8 @@ jail_<replaceable>www</replaceable>_devf <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 + 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 @@ -540,24 +555,24 @@ jail_<replaceable>www</replaceable>_devf understood.</para> <sect3 id="jails-service-jails-design"> - <title>Design</title> + <title>Design</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 + <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> + 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 @@ -570,8 +585,9 @@ jail_<replaceable>www</replaceable>_devf <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> + <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 @@ -579,79 +595,93 @@ jail_<replaceable>www</replaceable>_devf <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> + <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> + 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 - class="directory">/home/j</filename> directory.</para> + <para>Each jail will be mounted under the + <filename class="directory">/home/j</filename> + directory.</para> </listitem> + <listitem> - <para><filename class="directory">/home/j/mroot</filename> is - the template for each jail and the read-only partition for - all of the jails.</para> + <para><filename class="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 class="directory">/home/j</filename> + <para>A blank directory will be created for each jail + under the <filename class="directory">/home/j</filename> directory.</para> </listitem> + <listitem> - <para>Each jail will have a <filename - class="directory">/s</filename> directory, that will be - linked to the read-write portion of the system.</para> + <para>Each jail will have a + <filename class="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 + <para>Each jail shall have its own read-write system that + is based upon <filename class="directory">/home/j/skel</filename>.</para> </listitem> + <listitem> - <para>Each jailspace (read-write portion of each jail) shall - be created in <filename + <para>Each jailspace (read-write portion of each jail) + shall be created in <filename class="directory">/home/js</filename>.</para> </listitem> </itemizedlist> <note> <para>This assumes that the jails are based under the - <filename class="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 + <filename class="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. --> @@ -660,37 +690,40 @@ jail_<replaceable>www</replaceable>_devf <sect3 id="jails-service-jails-template"> <title>Creating the Template</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> + <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> + 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> + <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 + <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> @@ -698,6 +731,7 @@ jail_<replaceable>www</replaceable>_devf &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> @@ -709,23 +743,26 @@ jail_<replaceable>www</replaceable>_devf &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> + <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 - class="directory">s/</filename> locations. Real - directories or the creation of directories in the wrong - locations will cause the installation to fail.</para> + read-only file system. Please make sure that the + symlinks are created in the correct + <filename class="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> @@ -738,15 +775,15 @@ jail_<replaceable>www</replaceable>_devf &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> + <programlisting>WRKDIRPREFIX?= /s/portbuild</programlisting> - - <para>Having <literal>WRKDIRPREFIX</literal> set up this + <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 @@ -761,16 +798,16 @@ jail_<replaceable>www</replaceable>_devf <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>, + <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> + 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 @@ -786,12 +823,14 @@ jail_<replaceable>www</replaceable>_devf &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> + <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> @@ -815,34 +854,37 @@ jail_www_devfs_enable="YES"</programlist <warning> <para>The reason why the <varname>jail_<replaceable>name</replaceable>_rootdir</varname> - variable is set to <filename - class="directory">/usr/home</filename> instead of - <filename class="directory">/home</filename> is that the - physical path of the <filename - class="directory">/home</filename> directory on a - default &os; installation is <filename - class="directory">/usr/home</filename>. The + variable is set to + <filename class="directory">/usr/home</filename> + instead of + <filename class="directory">/home</filename> is that + the physical path of the + <filename class="directory">/home</filename> directory + on a default &os; installation is + <filename class="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> + 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> + <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 @@ -853,6 +895,7 @@ jail_www_devfs_enable="YES"</programlist &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 @@ -878,8 +921,8 @@ jail_www_devfs_enable="YES"</programlist 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> + 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> </sect3> @@ -888,13 +931,14 @@ jail_www_devfs_enable="YES"</programlist <title>Upgrading</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> + 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> @@ -910,13 +954,14 @@ jail_www_devfs_enable="YES"</programlist &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 + <para>The <maketarget>installworld</maketarget> run *** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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