Foundations of CentOS Linux: Enterprise Linux On the Cheap

Prelim
Contents at a Glance
Contents
About the Authors
About the Technical Reviewer
Acknowledgments
Introduction
	The Book
Installation
	Preinstallation Steps
	Installation
	Troubleshooting
	Summary
Bash
	Working with the Command-Line Interface
		Identifying the Working User
		The Linux Filesystem
		Directory Management
		Listing the Contents of a Directory
		Traversing Directories
		Absolute and Relative Paths
		Creating Directories
		Renaming and Moving Files
		Deleting Directories and Files
		Creating and Viewing Text Files
		Viewing the Contents of a File
	Text Processing
		Standard I/O Devices
		Redirection
		Piping
	Getting Help
	Environment Variables
	Creating and Running Your Own Script
	Summary
Client/Host Configuration
	The Boot Process
		The Boot Loader
		Kernel, Init, and Runlevels
		Services
	Keyboard Settings
	Language Settings
	Date and Time Settings
	Network Settings
	Graphics Settings
	Printer Settings
	Summary
Data Storage Management
	Provisioning a New Hard Drive
	Partitioning a Disk Using RAID
		Understanding RAID Types and Levels
		RAID 0
		RAID 1
		RAID 5
		Checking on RAID
	Partitioning with LVM
		Understanding How LVM Works
		Volume Groups
		Physical Volumes
		Logical Volumes
		Making Sure Your Volumes Work
		Finding More Information on LVM
	Summary
User Management
	Managing Users and Groups with the Graphical Interface
		Adding a User
		Changing User Properties
		Deleting a User
		Adding a Group
		Changing Group Properties
		Deleting a Group
	User Management on the Command Line
		Adding a User
		Changing User Properties
		Deleting a User
		Adding a Group
		Changing Group Properties
		Deleting a Group
	Implementing Disk Quotas
		Enabling User and Group Quotas on a Filesystem
		Setting Up the Quota Files
		Setting Up Quotas
		Setting Grace Periods
		Managing Quotas for Groups
		Enabling Quotas
		Reporting on Quotas
	Setting Resource Limits
	Summary
X Window System
	X.Org
		xorg.conf
		The Keyboard Section
		The Device Section
		The Screen Section
		The ServerLayout Section
		Making a New xorg.conf File
	The GNOME Desktop
		Top Panel
		Applications
		Places
		System
		Customizing Menus
		Launchers
		Separator, Update, Clock, and Sound Applet
		Bottom Panel
	XDMCP Remote Connections
		GDM Configuration
		Reloading Options with gdmflexiserver
	Using XDMCP with GDM
		Requesting an X Session with XDMCP
		XDMCP with X Query
		XDMCP with Xnest
	X with SSH
	Summary
Package Management
	RPM
	The RPM Filename Convention
	The rpm Command
		Installing a Package
		Signed Packages
		Importing Keys
		Verifying Packages
		Adding More Output
		Package Dependencies
		Upgrading a Package
		Removing a Package
		Querying a Package
		Information and File Contents of a Package
		Source RPMs
		The Spec File
		The rpmbuild Command
		Building a Binary Package from a Source Package
	YUM
		Installing Packages with YUM
		Removing Packages with YUM
		Updating Packages with YUM
		Searching Packages with YUM
		Adding Sources for YUM
		Creating Repositories for YUM
	Summary
Basic Linux Security
	System Logger
		Using syslog.conf
		Selectors
		Actions
		Detecting Intruders with the System Logger
	Automating Tasks with cron
		Using crontab
		Using cron.allow and cron.deny
		Working with the crontab File
		The crontab Task
		Browsing Available Tasks
		Removing Tasks
	Pluggable Authentication Modules
		Understanding PAM Rules and Configuration Files
		servicename
		Management Groups
		Control
		modulepath
		Testing PAM
		Testing pam_time.so with crond
		Finding Other PAM Modules
	Summary
Advanced Security
	Using Digital Certificates
	Creating Certificates
	Deploying Certificates
		Configuration Files
		Intermediate Certificates
		Certificate File Formats
		Signing Your Own Certificates
		Go Wild
	Intrusion Detection
		Monitoring the filesystem with RPM
		Monitoring the Filesystem with AIDE
		Monitoring the Network with Netfilter
	Security Enhanced Linux
		Why Use SELinux
		Enabling and Disabling SELinux
		SELinux Policy
		Drilling Down on Context
		Booleans
		Access Vectors
		Interactive Users
	Summary
Network Security
	The Firewall
		A Basic Firewall
		An Advanced Firewall
		How netfilter Works
		Viewing the Current Firewall
		Building netfilter Rules
		Using CentOS as a Router
		Using netfilter for IP Masquerading
		Handling Complex Protocols with netfilter
	tcp_wrappers
	Centralized Logging
		Configuring the Server to Receive Logs
		Configuring the Client to Send Logs
	Summary
Network Services
	OpenSSH
	The OpenSSH Configuration File
		Connecting to the OpenSSH Server
		Copying Files Securely with scp
		OpenSSH Keys
		OpenSSH Fingerprints
		Getting the Fingerprint Value
		The known_hosts File
		Making Your Own Keys
	The DHCP Server
		Setting Up the DHCP Server
		The DHCP Configuration File
		Assigning Fixed Addresses
		Organizing with Groups
	The NTP Server
		Client-Server Mode
		Symmetric Active/Passive Mode
		Broadcast Mode
		ntpq
	DNS
		Name Servers and Zones
		Name Resolution
		BIND Utilities
		rndc-confgen
		rndc
		named
		BIND Configuration Files
		The Contents of rndc.conf
		The Contents of named.conf
		Caching DNS
		The hints File
		dig
		nslookup
		Configuring a Caching DNS
		Configuring a Forwarder
		Configuring a Slave DNS
		Configuring a Master DNS
		Reverse Lookup
	The Squid Web Caching Server
		Installing Squid
		The Squid Main Configuration File
		The visible_hostname directive
		The cache_dir directive
		ACLs and ACL-operators
		Adding ACLs and ACL-operators
		How ACL-operators Work
		Talking to Squid Peers
		More Squid
	Summary
Open Source Databases
	ACID
	MySQL
		Setting Up MySQL
		Running the MySQL Server
		MySQL Users
		MySQL Monitor
		Securing the MySQL Root User
		Creating a Database
		Removing a Database
		Adding a User
		Removing a User
		Granting Privileges
		Removing Privileges
		Getting a List of Available Databases
		Creating Database Backups
		Restoring Databases Using Backups
		Restoring the toys Database
		Customizing the MySQL Server Configuration
	PostgreSQL
		Setting up PostgreSQL
		Starting PostgreSQL
		PostgreSQL Interactive Terminal
		Using the Interactive Terminal
		PostgreSQL Roles
		Creating a Role
		Removing a User
		Creating a Database
		Dropping a Database
		PostgreSQL Privileges
		Granting Privileges to Objects
		Revoking Privileges on Objects
		Changing Role Attributes
		Getting the List of Databases
		Creating Database Backups
		Restoring a Database
		Configuring PostgreSQL
		pg_hba.conf
	CRUD and Databases
		Creating
		Verifying the Newly Created Tables
		Viewing the Structures of the Tables
		Adding Entries to the Table
		Reading
		Updating
		Dropping Entries from a Table
	Summary
Linux Web Services
	The Role of a Web Server
	Apache Web Server
	Setting Up Apache
	Testing Apache
	Apache Server Directories
	The Apache Configuration File
		Apache Configuration File Sections
		Commonly Used Directives
		Section 1: Global Environment
		Section 2: Main Server Configuration
	Distributed Configuration Files
		DirectoryIndex
		Alias
		ScriptAlias
		Creating Another Document and cgi-bin Directory
	Virtual Hosts
		IP-Based and Name-Based Virtual Hosting
		The VirtualHost Directive
		Configuring Name-Based Virtual Hosting
	Adding PHP to Apache
	Secure Apache with SSL
		Securing with OpenSSL
		Startup Without a Passphrase
	Summary
File Sharing Services
	Very Secure FTP Daemon
		Configuring vsftpd
		vsftpd.conf
		ftpusers
		user_list
		Testing vsftpd
	NFS
		Configuring NFS
		Sharing a Directory Using NFS
		Sharing Directories Using NFS Daemons
		Mounting a Shared Directory As the Client
		Unmounting a Shared Directory as the Client
		Using exportfs
		Mounting Shared Directories at Boot Time
	Setting Up a Samba Server
		Installing Samba
		Configuring Samba
		lmhosts
		smbusers
		smb.conf
		Configuring Stand-Alone Server Options
		server string
		netbios name
		passdb backend
		Adding a Samba User
		Testing the Samba Stand-Alone Server
		Adding Shares
		Sharing a Printer
		Preparing the Printer to Pass Print Data in Raw Form
		Configuring Samba to Share a Printer
		Installing the Samba Printer to the Windows Client
	Summary
Linux Mail Servers
	Basic Email Concepts
		The Mail User Agent
		Mail Transfer Agent
		Mail Delivery Agent
		POP3 and IMAP
	Sendmail
		Sending Email with Sendmail
		Checking Mail with the mail Command
		sendmail.mc
		sendmail.cf
		The Sendmail Administrative Configuration Files
		local-host-names
		aliases
		access
		The trusted-users File
		The virtusertable File
		mailertable
	Postfix
		Installing Postfix
		Switching MTAs
		Sending Email with Postfix
		The Postfix Main Configuration File
		Postfix Administrative Configuration Files
		access
		aliases
		virtual
		transport
		generic
		canonical
		relocated
	Mail Servers and DNS
	Dovecot
		Installing Dovecot
		The dovecot.conf Configuration File
		Configuration Options
		protocols
		ssl_cert_file
		ssl_key_file
		ssl_key_password
		mail_location
		Configuring Dovecot for Maildir
		Configuring an Email Client to Send and Receive Email Using IMAP
		Checking the IMAP Maildir contents
		Receiving Email with POP3
		Checking the POP3 Maildir contents
		Dovecot and OpenSSL
		Using Evolution with OpenSSL
		Troubleshooting Tactics
	Summary
Directory Services
	The Need for Unified Authentication
	Network Information System
		Setting up NIS
		The NIS Server
		Creating Your First Domain
		ypserv.conf
		The NIS Client
		Binding to an NIS Domain
		yp.conf
		nsswitch.conf
		Testing the Setup
		Maps
		NIS Utilities
		ypwhich
		ypcat
		ypmatch
		yppasswd
		NIS with NFS
		Using NIS with NFS
	OpenLDAP
		Setting up OpenLDAP
		slapd
		ldap.conf
		slapd.conf
		Modules
		Schemas
		Your First Database
		Using the my-domain.com database
		LDIF Format
		Starting OpenLDAP
		Adding Entries with ldapadd
		Searching Entries with ldapsearch
		Changing Entries with ldapmodify
		Removing Entries Using ldapdelete
		Creating a Backup
		OpenLDAP and Samba
		Installing Perl Modules
		nss_ldap
		The nss_ldap Configuration File
		ldap.secret
		nsswitch.conf
		OpenLDAP
		OpenLDAP Client Configuration File
		Samba
		Smbldap-tools
		smbldap.conf
		smbldap_bind.conf
		Installing and Configuring smbldap-tools
		Joining the DCTOYS Domain Controller
		Testing the Samba and OpenLDAP Setup
		Troubleshooting Tactics
		Pitfall #1: Cannot log into the domain controller
		Pitfall #2: Cannot start the Samba server properly because only the nmbd process is running
	Summary
The Linux Kernel
	History of the Linux Kernel
	Types of Linux Kernels
	Kernel Modules
	Loading Kernel Modules
		insmod
		modprobe
		modprobe.conf
	Unloading Kernel Modules
		rmmod
		modprobe
		blacklist
	When to Recompile the Kernel
	Getting a New Linux Kernel
		Preparing to Configure the New Linux Kernel
	Ways to Configure the Kernel Sources
		Configuring the Kernel with the Command Line
		Configuring the Kernel Graphically
		Configuring the Kernel with menuconfig
	Preparing for Kernel Compilation
	Building the Kernel
	Building the Kernel Modules
	Making the Boot Loader Initialized RAM Disk
	Adding the New Kernel into the GRUB Boot Loader
	Your Turn
	Summary
Linux Virtualization
	Understanding Virtualization
		Deciding to Use Virtualization
		Xen
		Exploring Virtualization Technologies
		Full Virtualization
		Hardware-Assisted Virtualization
		Operating System Virtualization
		Paravirtualization
		Hardware Requirements
		Installing Xen
	The xend Daemon
		The xend Configuration Files
		xend-config.sxp
		xend-pci-permissive.sxp and xend-pci-quirks.sxp
		qemu-ifup
	The xend Network Configuration Scripts Directory
	Checking Dom-0
	Making a Guest with virt-install
		Preparing the Installation Media
		Using the virt-install Command
	Understanding the Guest Configuration File
	Xen Guest Example Configuration Files
	Connecting to a Guest
		Using xm
		Using virt-viewer
		Using vncviewer
	Shutting Down a Guest
	Starting a Guest
	Cloning a Guest
	Cleaning Up
	Summary
Linux Troubleshooting
	The CentOS Rescue Environment
	Exploring the Rescue Environment
	Troubleshooting Checklist
		Changed the Root Password
		Bootloader Was Overwritten
		You’re Experimenting with the Files in /etc
		Skipping /mnt/sysimage
		Finding the Affected System’s Root (/) Directory
	Mounting Logical Volumes
		Mounting Logical Volumes
	Single-User Mode
		Booting into Single-User Mode
	My New Kernel Is Stuck!
		Creating the Required Device Files
	Summary
Index
	¦Special Characters and
	Numerics
	¦A
	¦B
	C
	¦
	¦D
	¦E
	¦F
	¦G
	¦ ¦H I
	¦J
	K
	¦
	¦L
	¦M
	¦N
	¦O
	¦P
	¦Q
	¦R
	¦S
	¦T
	¦U
	¦V
	¦W
	¦X
	¦Y
	¦Z