scis.regis.edu ● scis@regis.edu

CS 468: Advanced UNIXClass 2

Dr. Jesús BorregoRegis University

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Topics

•Homework 1 solutions•How to capture output to file•Installation of system•User Administration•How to capture output to file•Homework 2 Assignment•Q&A

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Capturing script interaction

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Adding Users

Tasks:•Assign user name•Add new entry to password file•Add entry to group file•Create home directory for user•Create startup files for user•Notify user

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Password file format

•username:•password:•userID:•groupID:•personal:•home directory:•startup

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username:password:userID:groupID:personal:home directory:startup

Group file

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LDAP

•Lightweight Directory Access Protocol•Smaller version of Directory Services

X.500•Table look up of entries; look up an entry

and it finds attributes•Used to determine access given to a user•Used by most operating systems,

including Unix, Linux, and Windows ▫MS: Active Directory

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Directory Services Overview•Directory Concept

▫Look up resources based on known attributes

•Based on IETF and ISB X.500▫http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1

777.html

•DAP – Directory Access Protocol▫Specified in X.511

•LDAP – Lightweight DAP▫Clients can read and query the directory

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Directory Services•Entities have attributes that can be

used to search▫Files can have access descriptors for

users•Contains a number of records with

(attribute, value) pairs•Collection of directory entries is

called a Directory Information Base (DIB)

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Source: Tanenbaum, A., & Steen, M. V. (2007). Distributed systems: Principles and paradigms (2nd ed.). Upper Saddle River, NJ: Pearson Prentice Hall.

Directory Services Overview•Resources can be:

▫Computers, servers, databases, printers▫People, groups▫Anything on a network

•Dependent on TCP/IP for functionality

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Active Directory Concepts•Namespace – name or group of

names defined according to a naming convention

•Name resolution – the ability to attribute a name to an object on the network▫Distinguished Name (DN) – from the root

Division/Department/Section/Unit/Group

▫Relative Distinguished Name (RDN) – relative to a particular location ./Group

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Microsoft Directory Services•Services defined as:

▫Single point of access to network resources

▫Adaptive and expandable information source

▫Common policy or set of rules▫Methods for querying directory

objects

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

MS Active Directory Framework•Logical Elements

▫Structure▫Relationships

•Physical Components ▫AD Sites▫Domain Controllers

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Logical Elements

•Objects•Schema•Domains•Containers and OUs•Trees and Forests•Sites and Domain Controllers

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Objects•“Any item contained in the directory that has a common set of attributes”

•Examples: users, workstations, printers, databases, files

•Has properties and is defined by class definitions

•Can be a parent or child

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Object Attributes•Property = Attribute•A set of information defining an object•Children inherit attributes of parents•Actual value defines object uniquely

▫A printer can be a parent and has attributes Location, brand, properties

▫An HP OfficeJet J4680 at IP 10.10.10.15 is a specific printer

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Object Classes•Classes grouped by attributes•Sample classes:

▫Users▫Groups▫Computers▫Organizational Units▫Databases▫…

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Structure Components•Containers

▫Store objects in the directory (domains, OUs)

•Domains▫Form security boundaries on a network▫Security settings do not cross over domains

•OUs▫Subdivide directory structure into smaller

units Makes administration easier and more

manageable

04/19/23

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Relational Components •Trees

▫A contiguous namespace▫Domains interconnected via relationships

•Forests▫Collection of trees

•Global Catalog Server▫Central repository of objects

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Trees•Logical hierarchy of domains within the

namespace▫Within the tree, domains are

interconnected in trust relationships•Trust Relationship

▫Formed when two or more domains are joined in the sane namespace and a link is formed

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Forests•When companies merge

▫Individual trees are merged into a forest•Allows established trees to coexist in a

new network•First tree created in the forest becomes

the root (by default)•Trees in forest share common schema,

configuration, and catalog server

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Source: Schwartz, R. (2000). Windows 2000 Active Directory survival guide: Planning and implementation. New York, NY: John Wiley & Sons

Chapter 7: Adding New Users

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User management commands

•To add users: useradd•To delete users: userdel•To modify users: usermod

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Login names rules

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Password encryption

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Encryption

•Crypt – based on DES•MDT•SHA256•Blowfish

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UserID

•Login names are understandable to users•UID is used by the system internally•UIDs must be unique across the

organization•User IDs are managed by LDAP

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Group ID

•Defined in /etc/groups•32-bit number•GID 0 – system•Group ID for a user is stored in the

password file•GECOS – General Comprehensive OS

▫Contains general information about user p.181

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User information

•Home Directory•Login shell (bash default)•Login scripts

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Other startup files

•See .bashrc•See .bash_profile•Review table 7.3, page 1898

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Startupfiles

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Bashprofile

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AddingUsers

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Useraccountoptions

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Chapter 12:

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Installing UNIX

Installation methods:•From media (DVD)•From network installation (DHCP, TFTP) that boots system without media

▫Retrieves files from network (HTTPS, NFS, FTP)

•From network card•Others (system dependent): Kickstart, LILO, AutoYaST

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Installation documentation

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Keywords for JumpStart

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Packages

•Used to distribute software•Can also be used to release other files•Attempt to make installation easier than

using tar.gz archives•Include dependencies to determine what

components are required for a given installation

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Package concepts

•Release – a software baseline•Component – Subset of software within a

release •Architecture – Specific class of hardware•Packages – elements that make up

components and releases

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Binaries and config files

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Software Distribution Commands

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Revision Control

•Need to keep track of versions for a system – Why?

•Can do backups but they become cumbersome

•CVS•SubVersion•Revision•Version•Branches•Trunks

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Branch Management

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Localization and Configuration

•Need to configure all devices and file systems

•Need to maintain inventory of devices•Software released involve maintaining

licenses•Set up a test environment before

releasing changes•If possible, take advantage of

management tools

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Questions?

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