[system-administrators-guide] Updates to suit F21
stephenw
stephenw at fedoraproject.org
Wed Jan 28 08:05:02 UTC 2015
commit 59f032c39a6c50583c359b8dfe3012e63b645011
Author: Stephen Wadeley <swadeley at redhat.com>
Date: Wed Jan 28 09:03:46 2015 +0100
Updates to suit F21
en-US/Managing_Users_and_Groups.xml | 148 ++++++++++++++++++++---------------
en-US/images/managing_users.png | Bin 0 -> 34627 bytes
2 files changed, 85 insertions(+), 63 deletions(-)
---
diff --git a/en-US/Managing_Users_and_Groups.xml b/en-US/Managing_Users_and_Groups.xml
index d4ad691..b065879 100644
--- a/en-US/Managing_Users_and_Groups.xml
+++ b/en-US/Managing_Users_and_Groups.xml
@@ -20,18 +20,18 @@
<secondary>GID</secondary>
</indexterm>
<para>
- The control of users and groups is a core element of &MAJOROS; system administration. This chapter explains how to add, manage, and delete users and groups in the graphical user interface and on the command line, and covers advanced topics, such as enabling password aging or creating group directories.
+ The control of users and groups is a core element of &MAJOROS; system administration. This chapter explains how to add, manage, and delete users and groups in the graphical user interface and on the command line, and covers advanced topics, such as creating group directories.
</para>
<section id="s1-users-groups-introduction">
<title>Introduction to Users and Groups</title>
<para>
- While users can be either people (meaning accounts tied to physical users) or accounts which exist for specific applications to use, groups are logical expressions of organization, tying users together for a common purpose. Users within a group can read, write, or execute files owned by that group.
+ While users can be either people (meaning accounts tied to physical users) or accounts which exist for specific applications to use, groups are logical expressions of organization, tying users together for a common purpose. Users within a group share the same permissions to read, write, or execute files owned by that group.
</para>
<para>
Each user is associated with a unique numerical identification number called a <firstterm>user ID</firstterm> (<acronym>UID</acronym>). Likewise, each group is associated with a <firstterm>group ID</firstterm> (<acronym>GID</acronym>). A user who creates a file is also the owner and group owner of that file. The file is assigned separate read, write, and execute permissions for the owner, the group, and everyone else. The file owner can be changed only by <systemitem class="username">root</systemitem>, and access permissions can be changed by both the <systemitem class="username">root</systemitem> user and file owner.
</para>
<para>
- Additionally, &MAJOROS; supports <firstterm>access control lists</firstterm> (<acronym>ACLs</acronym>) for files and directories which allow permissions for specific users outside of the owner to be set. For more information about this feature, see the <ulink url="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/ch-acls.html"><citetitle pubwork="chapter">Access Control Lists</citetitle></ulink> chapter of the <ulink url="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/index.html"><citetitle pubwork="book">Storage Administration Guide</citetitle></ulink>.
+ Additionally, &MAJOROS; supports <firstterm>access control lists</firstterm> (<acronym>ACLs</acronym>) for files and directories which allow permissions for specific users outside of the owner to be set. For more information about this feature, see the <ulink url="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Storage_Administration_Guide/ch-acls.html"><citetitle pubwork="chapter">Access Control Lists</citetitle></ulink> chapter of the <ulink url="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Storage_Administration_Guide/index.html"><citetitle pubwork="book">Storage Administration Guide</citetitle></ulink>.
</para>
<section id="s2-users-groups-private-groups">
<title>User Private Groups</title>
@@ -48,11 +48,6 @@
<secondary>tools for management of</secondary>
<tertiary><command>groupadd</command></tertiary>
</indexterm>
- <indexterm>
- <primary>groups</primary>
- <secondary>tools for management of</secondary>
- <tertiary><application>system-config-users</application></tertiary>
- </indexterm>
<para>
&MAJOROS; uses a <firstterm>user private group</firstterm> (<firstterm>UPG</firstterm>) scheme, which makes UNIX groups easier to manage. A user private group is created whenever a new user is added to the system. It has the same name as the user for which it was created and that user is the only member of the user private group.
</para>
@@ -60,7 +55,10 @@
User private groups make it safe to set default permissions for a newly created file or directory, allowing both the user and <emphasis>the group of that user</emphasis> to make modifications to the file or directory.
</para>
<para>
- The setting which determines what permissions are applied to a newly created file or directory is called a <firstterm>umask</firstterm> and is configured in the <filename>/etc/bashrc</filename> file. Traditionally on UNIX systems, the <command>umask</command> is set to <command>022</command>, which allows only the user who created the file or directory to make modifications. Under this scheme, all other users, <emphasis>including members of the creator's group</emphasis>, are not allowed to make any modifications. However, under the UPG scheme, this <quote>group protection</quote> is not necessary since every user has their own private group.
+ The setting which determines what permissions are applied to a newly created file or directory is called a <firstterm>umask</firstterm> and is configured in the <filename>/etc/bashrc</filename> file. Traditionally on UNIX-based systems, the <command>umask</command> is set to <command>022</command>, which allows only the user who created the file or directory to make modifications. Under this scheme, all other users, <emphasis>including members of the creator's group</emphasis>, are not allowed to make any modifications. However, under the UPG scheme, this <quote>group protection</quote> is not necessary since every user has their own private group.
+ </para>
+ <para>
+ A list of all groups is stored in the <filename>/etc/group</filename> configuration file.
</para>
</section>
<section id="s2-users-groups-shadow-utilities">
@@ -97,34 +95,34 @@
</listitem>
</itemizedlist>
<para>
- Most utilities provided by the <package>shadow-utils</package> package work properly whether or not shadow passwords are enabled. However, since password aging information is stored exclusively in the <filename>/etc/shadow</filename> file, any commands which create or modify password aging information do not work. The following is a list of utilities and commands that do not work without first enabling shadow passwords:
+ Most utilities provided by the <package>shadow-utils</package> package work properly whether or not shadow passwords are enabled. However, since password aging information is stored exclusively in the <filename>/etc/shadow</filename> file, some utilities and commands do not work without first enabling shadow passwords:
</para>
<itemizedlist>
<listitem>
<para>
- The <command>chage</command> utility.
+ The <command>chage</command> utility for setting password-aging parameters. For details, see the <ulink url="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Security_Guide/chap-Hardening_Your_System_with_Tools_and_Services.html#sec-Password_Security">Password Security</ulink> section in the <citetitle pubwork="book">&MAJOROSVER; Security Guide</citetitle>.
</para>
</listitem>
<listitem>
<para>
- The <command>gpasswd</command> utility.
+ The <command>gpasswd</command> utility for administrating the <filename>/etc/group</filename> file.
</para>
</listitem>
<listitem>
<para>
- The <command>usermod</command> command with the <option>-e</option> or <option>-f</option> option.
+ The <command>usermod</command> command with the <option>-e, --expiredate</option> or <option>-f, --inactive</option> option.
</para>
</listitem>
<listitem>
<para>
- The <command>useradd</command> command with the <option>-e</option> or <option>-f</option> option.
+ The <command>useradd</command> command with the <option>-e, --expiredate</option> or <option>-f, --inactive</option> option.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section id="s1-users-configui">
- <title>Using the User Manager Tool</title>
+ <title>Managing Users in a Graphical Environment</title>
<indexterm>
<primary>users</primary>
<see>user configuration</see>
@@ -134,10 +132,6 @@
<see>group configuration</see>
</indexterm>
<indexterm>
- <primary><command>system-config-users</command></primary>
- <see>user configuration and group configuration</see>
- </indexterm>
- <indexterm>
<primary>user configuration</primary>
<secondary>viewing list of users</secondary>
</indexterm>
@@ -146,22 +140,32 @@
<secondary>viewing list of groups</secondary>
</indexterm>
<indexterm>
- <primary><application>User Manager</application></primary>
+ <primary><application>the Users settings tool</application></primary>
<see>user configuration</see>
</indexterm>
<para>
- The <application>User</application> utility allows you to view, modify, add, and delete local users in the graphical user interface.</para>
+ The <application>Users</application> utility allows you to view, modify, add, and delete local users in the graphical user interface.</para>
<section id="s2-redhat-config-users-list">
- <title>Viewing Users and Groups</title>
+ <title>Using the Users Settings Tool</title>
-<!-- changes to remove outdated GUI description and screenshots -->
-<para>Press the <keycap>Super</keycap> key to enter the Activities Overview, type <command>Users</command> and then press <keycap>Enter</keycap>. The <application>Users</application> utility appears. The <keycap>Super</keycap> key appears in a variety of guises, depending on the keyboard and other hardware, but often as either the Windows or Command key, and typically to the left of the Spacebar.</para>
+<para>Press the <keycap>Super</keycap> key to enter the Activities Overview, type <command>Users</command> and then press <keycap>Enter</keycap>. The <application>Users</application> settings tool appears. The <keycap>Super</keycap> key appears in a variety of guises, depending on the keyboard and other hardware, but often as either the Windows or Command key, and typically to the left of the Spacebar.</para>
<para>
- To make changes to the user accounts first select the <guibutton>Unlock</guibutton> button and authenticate yourself as indicated by the dialog box that appears. Note that unless you have superuser privileges, the application will prompt you to authenticate as <systemitem class="username">root</systemitem>. To add and remove users select the <guibutton>+</guibutton> and <guibutton>-</guibutton> button respectively. To edit a users language setting, select the language and a drop-down menu appears.
-</para>
-
-
+ To make changes to the user accounts, first select the <guibutton>Unlock</guibutton> button and authenticate yourself as indicated by the dialog box that appears. Note that unless you have superuser privileges, the application will prompt you to authenticate as <systemitem class="username">root</systemitem>. To add and remove users, select the <guibutton>+</guibutton> and <guibutton>-</guibutton> button respectively. To add a user to the administrative group <systemitem class="groupname">wheel</systemitem>, change the <guimenu>Account Type</guimenu> from <literal>Standard</literal> to <literal>Administrator</literal>. To edit a user's language setting, select the language and a drop-down menu appears. </para>
+<figure id="fig-managing-users">
+ <title>The Users Settings Tool</title>
+ <mediaobject id="mediaobj-managing-users">
+ <imageobject>
+ <imagedata
+ scalefit="0"
+ fileref="images/managing_users.png"
+ format="PNG" />
+ </imageobject>
+ <textobject><para>The <application>Users</application> settings tool</para></textobject>
+ </mediaobject>
+ </figure>
+<para>
+ When a new user is created, the account is disabled until a password is set. The <guimenu>Add User</guimenu> menu contains the options to set a password by the administrator immediately, or to allow the user to choose a password at the first login. </para>
</section>
</section>
@@ -175,12 +179,7 @@
<indexterm>
<primary>users</primary>
<secondary>tools for management of</secondary>
- <tertiary><application>User Manager</application></tertiary>
- </indexterm>
- <indexterm>
- <primary>groups</primary>
- <secondary>tools for management of</secondary>
- <tertiary><application>User Manager</application></tertiary>
+ <tertiary><application>the Users setting tool</application></tertiary>
</indexterm>
<indexterm>
<primary>groups</primary>
@@ -188,7 +187,7 @@
<tertiary><command>groupadd</command></tertiary>
</indexterm>
<para>
- The easiest way to manage users and groups on &MAJOROS; is to use the <application>User Manager</application> application as described in <xref linkend="s1-users-configui" />. However, if you prefer command line tools or do not have the X Window System installed, you can use command line utilities that are listed in <xref linkend="table-users-tools" />.
+ Apart from the <application>Users</application> settings tool described in <xref linkend="s1-users-configui" />, which is designed for basic managing of users, you can use command line tools for managing users and groups that are listed in <xref linkend="table-users-tools" />.
</para>
<table id="table-users-tools">
<title>Command line utilities for managing users and groups</title>
@@ -208,6 +207,14 @@
<tbody>
<row>
<entry>
+ <command>id</command>
+ </entry>
+ <entry>
+ Displays user and group IDs.
+ </entry>
+ </row>
+ <row>
+ <entry>
<command>useradd</command>, <command>usermod</command>, <command>userdel</command>
</entry>
<entry>
@@ -246,6 +253,14 @@
Utilities that can be used for the conversion of passwords to shadow passwords, or back from shadow passwords to standard passwords.
</entry>
</row>
+ <row>
+ <entry>
+ <command>grpconv</command>, <command>grpunconv</command>
+ </entry>
+ <entry>
+ Similar to the previous, these utilities can be used for conversion of shadowed information for group accounts.
+ </entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -265,11 +280,11 @@
<tertiary><command>useradd</command></tertiary>
</indexterm>
<para>
- To add a new user to the system, typing the following at a shell prompt as <systemitem class="username">root</systemitem>:
+ To add a new user to the system, type the following at a shell prompt as <systemitem class="username">root</systemitem>:
</para>
<synopsis><command>useradd</command> <optional><replaceable>options</replaceable></optional> <replaceable>username</replaceable></synopsis>
<para>
- …where <replaceable>options</replaceable> are command line options as described in <xref linkend="table-useradd-options" />.
+ …where <replaceable>options</replaceable> are command-line options as described in <xref linkend="table-useradd-options" />.
</para>
<indexterm>
<primary>user configuration</primary>
@@ -281,10 +296,10 @@
</para>
<synopsis><command>passwd</command> <replaceable>username</replaceable></synopsis>
<para>
- Optionally, you can set password aging policy. See <xref linkend="s2-users-tools-password-aging" /> for information on how to enable password aging.
+ Optionally, you can set a password aging policy. See <xref linkend="s2-users-tools-password-aging" /> for information on how to enable password aging.
</para>
<table id="table-useradd-options">
- <title>useradd command line options</title>
+ <title>Common useradd command-line options</title>
<tgroup cols="2">
<colspec colname="option" colnum="1" colwidth="30*" />
<colspec colname="description" colnum="2" colwidth="70*" />
@@ -328,7 +343,7 @@
<option>-f</option> <replaceable>days</replaceable>
</entry>
<entry>
- Number of days after the password expires until the account is disabled. If <literal>0</literal> is specified, the account is disabled immediately after the password expires. If <literal>-1</literal> is specified, the account is not be disabled after the password expires.
+ Number of days after the password expires until the account is disabled. If <literal>0</literal> is specified, the account is disabled immediately after the password expires. If <literal>-1</literal> is specified, the account is not disabled after the password expires.
</entry>
</row>
<row>
@@ -336,7 +351,7 @@
<option>-g</option> <replaceable>group_name</replaceable>
</entry>
<entry>
- Group name or group number for the user's default group. The group must exist prior to being specified here.
+ Group name or group number for the user's default (primary) group. The group must exist prior to being specified here.
</entry>
</row>
<row>
@@ -344,7 +359,7 @@
<option>-G</option> <replaceable>group_list</replaceable>
</entry>
<entry>
- List of additional (other than default) group names or group numbers, separated by commas, of which the user is a member. The groups must exist prior to being specified here.
+ List of additional (supplementary, other than default) group names or group numbers, separated by commas, of which the user is a member. The groups must exist prior to being specified here.
</entry>
</row>
<row>
@@ -406,6 +421,9 @@
</tbody>
</tgroup>
</table>
+ <para>
+ The command-line options associated with the <command>usermod</command> command are essentially the same. Note that if you want to add a user to another supplementary group, you need to use the <option>-a, --append</option> option with the <option>-G</option> option. Otherwise the list of supplementary groups for the user will be overwritten by those specified with the <command>usermod -G</command> command.
+ </para>
<bridgehead id="bh-users-tools-users-add-explanation">
Explaining the Process
</bridgehead>
@@ -515,7 +533,7 @@
</listitem>
<listitem>
<para>
- The GID matches the one listed for user <systemitem class="username">juan</systemitem> in <filename>/etc/passwd</filename>.
+ The GID matches the one listed for <systemitem class="username">juan</systemitem>'s primary group in <filename>/etc/passwd</filename>.
</para>
</listitem>
</itemizedlist>
@@ -550,26 +568,24 @@
<para>
A directory for user <systemitem class="username">juan</systemitem> is created in the <filename class="directory">/home/</filename> directory:
</para>
- <screen>~]# <command>ls -l /home</command>
-total 4
-drwx------. 4 juan juan 4096 Mar 3 18:23 juan</screen>
+ <screen>~]# <command>ls -ld /home/juan</command>
+drwx------. 4 juan juan 4096 Mar 3 18:23 /home/juan</screen>
<para>
This directory is owned by user <systemitem class="username">juan</systemitem> and group <systemitem class="groupname">juan</systemitem>. It has <firstterm>read</firstterm>, <firstterm>write</firstterm>, and <firstterm>execute</firstterm> privileges <emphasis>only</emphasis> for the user <systemitem class="username">juan</systemitem>. All other permissions are denied.
</para>
</step>
<step>
<para>
- The files within the <filename class="directory">/etc/skel/</filename> directory (which contain default user settings) are copied into the new <filename class="directory">/home/juan/</filename> directory. The contents of <filename class="directory">/etc/skel/</filename> may vary depending on installed applications.
+ The files within the <filename class="directory">/etc/skel/</filename> directory (which contain default user settings) are copied into the new <filename class="directory">/home/juan/</filename> directory. The contents of <filename class="directory">/etc/skel/</filename> may vary depending on installed applications:
</para>
<screen>~]# <command>ls -la /home/juan</command>
-total 28
+total 24
drwx------. 4 juan juan 4096 Mar 3 18:23 .
drwxr-xr-x. 5 root root 4096 Mar 3 18:23 ..
-rw-r--r--. 1 juan juan 18 Jul 09 08:43 .bash_logout
-rw-r--r--. 1 juan juan 176 Jul 09 08:43 .bash_profile
-rw-r--r--. 1 juan juan 124 Jul 09 08:43 .bashrc
-drwxr-xr-x. 4 juan juan 4096 Jul 09 08:43 .mozilla
--rw-r--r--. 1 juan juan 658 Jul 09 08:43 .zshrc</screen>
+drwxr-xr-x. 4 juan juan 4096 Jul 09 08:43 .mozilla</screen>
</step>
</procedure>
<para>
@@ -591,10 +607,10 @@ drwxr-xr-x. 4 juan juan 4096 Jul 09 08:43 .mozilla
</para>
<synopsis><command>groupadd</command> <optional><replaceable>options</replaceable></optional> <replaceable>group_name</replaceable></synopsis>
<para>
- …where <replaceable>options</replaceable> are command line options as described in <xref linkend="table-groupadd-options" />.
+ …where <replaceable>options</replaceable> are command-line options as described in <xref linkend="table-groupadd-options" />.
</para>
<table id="table-groupadd-options">
- <title>groupadd command line options</title>
+ <title>Common groupadd command-line options</title>
<tgroup cols="2">
<colspec colnum="1" colname="option" colwidth="30*" />
<colspec colnum="2" colname="description" colwidth="70*" />
@@ -684,7 +700,7 @@ drwxr-xr-x. 4 juan juan 4096 Jul 09 08:43 .mozilla
<tertiary>forcing expiration of</tertiary>
</indexterm>
<para>
- For security reasons, it is advisable to require users to change their passwords periodically. This can either be done when adding or editing a user on the <guilabel>Password Info</guilabel> tab of the <application>User Manager</application> application, or by using the <command>chage</command> command.
+ For security reasons, it is advisable to require users to change their passwords periodically. This can be done by using the <command>chage</command> command.
</para>
<important>
<title>Shadow passwords must be enabled to use chage</title>
@@ -886,7 +902,7 @@ autodetach off</programlisting>
<secondary>and shared directories</secondary>
</indexterm>
<para>
- System administrators usually like to create a group for each major project and assign people to the group when they need to access that project's files. With this traditional scheme, file managing is difficult; when someone creates a file, it is associated with the primary group to which they belong. When a single person works on multiple projects, it becomes difficult to associate the right files with the right group. However, with the UPG scheme, groups are automatically assigned to files created within a directory with the <firstterm>setgid</firstterm> bit set. The setgid bit makes managing group projects that share a common directory very simple because any files a user creates within the directory are owned by the group which owns the directory.
+ System administrators usually like to create a group for each major project and assign people to the group when they need to access that project's files. With this traditional scheme, file management is difficult; when someone creates a file, it is associated with the primary group to which they belong. When a single person works on multiple projects, it becomes difficult to associate the right files with the right group. However, with the UPG scheme, groups are automatically assigned to files created within a directory with the <firstterm>setgid</firstterm> bit set. The setgid bit makes managing group projects that share a common directory very simple because any files a user creates within the directory are owned by the group that owns the directory.
</para>
<para>
For example, a group of people need to work on files in the <filename class="directory">/opt/myproject/</filename> directory. Some people are trusted to modify the contents of this directory, but not everyone.
@@ -912,20 +928,26 @@ autodetach off</programlisting>
</step>
<step>
<para>
- Allow users to create files within the directory, and set the setgid bit:
+ Allow users in the group to create files within the directory and set the setgid bit:
</para>
<screen><command>chmod 2775 /opt/myproject</command></screen>
- </step>
- </procedure>
<para>
At this point, all members of the <systemitem class="groupname">myproject</systemitem> group can create and edit files in the <filename class="directory">/opt/myproject/</filename> directory without the administrator having to change file permissions every time users write new files. To verify that the permissions have been set correctly, run the following command:
</para>
- <screen>~]# <command>ls -l /opt</command>
-total 4
-drwxrwsr-x. 3 root myproject 4096 Mar 3 18:31 myproject</screen>
+ <screen>~]# <command>ls -ld /opt/myproject</command>
+drwxrwsr-x. 3 root myproject 4096 Mar 3 18:31 /opt/myproject
+</screen>
+ </step>
+ <step>
+ <para>
+ Add users to the <systemitem class="groupname">myproject</systemitem> group:
+ </para>
+ <screen><command>usermod -aG myproject <replaceable>username</replaceable></command></screen>
+ </step>
+ </procedure>
</section>
</section>
- <section id="s1-users-groups-additional-resources">
+ <section id="sect-Users_and_Groups-Resources">
<title>Additional Resources</title>
<indexterm>
<primary>groups</primary>
@@ -1000,12 +1022,12 @@ drwxrwsr-x. 3 root myproject 4096 Mar 3 18:31 myproject</screen>
</listitem>
<listitem>
<para>
- <systemitem>pwconv</systemitem>(8) — The manual page for the <command>pwconv</command> command documents how to use it to convert standard passwords to shadow passwords.
+ <systemitem>pwconv</systemitem>(8) — The manual page for the <command>pwconv</command>, <command>pwunconv</command>, <command>grpconv</command>, and <command>grpunconv</command> commands documents how to convert shadowed information for passwords and groups.
</para>
</listitem>
<listitem>
<para>
- <systemitem>pwunconv</systemitem>(8) — The manual page for the <command>pwunconv</command> command documents how to use it to convert shadow passwords to standard passwords.
+ <systemitem>id</systemitem>(1) — The manual page for the <command>id</command> command documents how to display user and group IDs.
</para>
</listitem>
</itemizedlist>
diff --git a/en-US/images/managing_users.png b/en-US/images/managing_users.png
new file mode 100644
index 0000000..0e020b3
Binary files /dev/null and b/en-US/images/managing_users.png differ
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