Chapter 1 Designing a Package

Before you build a package, you need to know which files you need to create and the commands you need to execute. You also need to consider your application software's requirements and the needs of your customers. Your customers are the administrators who will be installing your package. This chapter discusses the files, commands, and criteria you should know and consider before building a package.

This is a list of the information in this chapter.

• Where to Find Packaging Tasks

• What Are Packages?

• Package Components

• Considerations Before Building a Package

• Packaging Commands, Files, and Scripts

Where to Find Packaging Tasks

Use these task maps to find step-by-step instructions for building and verifying packages.

• The Process of Building a Package (Task Map)

• Creating Information Files and Installation Scripts (Task Map)

• Verifying and Transferring a Package (Task Map)

What Are Packages?

Application software is delivered in units called packages. A package is a collection of files and directories that are required for a software product. A package is usually designed and built by the application developer after completing the development of the application code. A software product needs to be built into one or more packages so that it can easily be transferred to a distribution medium. Then, the software product can be mass produced and installed by administrators.

A package is a collection of files and directories in a defined format. This format conforms to the application binary interface (ABI), which is a supplement to the System V Interface Definition.

Package Components

The components of a package fall into two categories.

• package objects are the application files to be installed.

• control files control how, where, and if the package is installed.

The control files are also divided into two categories: information files and installation scripts. Some control files are required. Some control files are optional.

To package your applications, you must first create the required components, and any optional components, that make up your package. You can then build the package by using the pkgmk command.

To build a package, you must provide the following:

• Package objects (the application software's files and directories)

• Two required information files (the pkginfo and prototype files)

• Optional information files

• Optional installation scripts

The following figure describes the contents of a package.

Figure 1–1 The Contents of a Package

Required Package Components

You must create the following components before you build your package:

• Package objects

  These components make up the application. They can consist of the following items:

  • Files (executable files or data files)

  • Directories

  • Named pipes

  • Links

  • Devices

• The pkginfo file

  The pkginfo file is a required package information file that defines parameter values. Parameter values include the package abbreviation, the full package name, and the package architecture. For more information, see Creating a pkginfo File and the pkginfo(4) man page.

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  Note –

  There are two pkginfo(1) man pages. The first man page describes a section 1 command that displays information about installed packages. The second man page describes a section 4 file that describes the characteristics of a package. When accessing the man pages, be sure to specify the applicable man page section. For example: man -s 4 pkginfo.

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• The prototype file

  The prototype file is a required package information file that lists the components of the package. One entry exists for each package object, information file, and installation script. An entry consists of several fields of information that describe each component, including its location, attributes, and file type. For more information, see Creating a prototype File and the prototype(4) man page.

Optional Package Components

Package Information Files

You can include four optional package information files in your package:

• The compver file

  Defines previous versions of the package that are compatible with this version of your package.

• The depend file

  Indicates other packages that have a special relationship with your package.

• The space file

  Defines disk space requirements for the target environment, beyond what is required by the objects defined in the prototype file. For example, additional space might be needed for files that are dynamically created at installation time.

• The copyright file

  Defines the text for a copyright message that displays at the time of package installation.

Each package information file should have an entry in the prototype file. See Creating Information Files for more information on creating these files.

Package Installation Scripts

Installation scripts are not required. However, you can provide scripts that perform customized actions during the installation of your package. An installation script has the following characteristics:

• The script is composed of Bourne shell commands.

• The script's file permissions should be set to 0644.

• The script does not need to contain the shell identifier (#! /bin/sh).

The four script types are as follows:

• The request script

  The request script requests input from the administrator who is installing the package.

• The checkinstall script

  The checkinstall script performs special file system verification.

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  Note –

  The checkinstall script is only available with the Solaris^TM 2.5 release and compatible releases.

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• Procedure scripts

  Procedure scripts define actions that occur at particular points during package installation and removal. You can create four procedure scripts with these predefined names: preinstall, postinstall, preremove, and postremove.

• Class action scripts

  Class action scripts define a set of actions to be performed on a group of objects.

See Creating Installation Scripts for a more information on installation scripts.

Considerations Before Building a Package

Before building a package, you need to decide whether your product will consist of one or more packages. Note that many small packages take longer to install than one big package. Although creating a single package is a good idea, doing so is not always possible. If you decide to build more than one package, you need to determine how to segment the application code. This section provides a list of criteria to use when planning to build a package.

Many of the packaging criteria present trade-offs among themselves. Satisfying all requirements equally is often difficult. These criteria are presented in order of importance. However, this sequence is meant to serve as a flexible guide depending on the circumstances. Although each criterion is important, it is up to you to optimize these requirements to produce a good set of packages.

For more design ideas, see Chapter 6, Advanced Techniques for Creating Packages.

Make Packages Remotely Installable

All packages must be remotely installable. Being remotely installable means that the administrator installing your package might be trying to install it on a client system, not necessarily to the root (/) file system where the pkgadd command is being executed.

Optimize for Client-Server Configurations

Consider the various types of system software configurations (for example, standalone system and server) when laying out packages. Good packaging design divides the affected files to optimize installation of each configuration type. For example, the contents of the root (/) and /usr file systems should be segmented so that server configurations can easily be supported.

Package by Functional Boundaries

Packages should be self-contained and distinctly identified with a set of functionality. For example, a package that contains UFS should contain all UFS utilities and be limited to only UFS binaries.

Packages should be organized from a customer's point of view into functional units.

Package Along Royalty Boundaries

Put code that requires royalty payments due to contractual agreements in a dedicated package or group of packages. Do not disperse the code into more packages than necessary.

Package by System Dependencies

Keep system-dependent binaries in dedicated packages. For example, the kernel code should be in a dedicated package, with each implementation architecture consisting of a distinct package instance. This rule also applies to binaries for different architectures. For example, binaries for a SPARC system would be in one package and binaries for an x86 system would be in another package.

Eliminate Overlap in Packages

When constructing packages, eliminate duplicate files whenever possible. Unnecessary duplication of files results in support and version difficulties. If your product has multiple packages, repeatedly compare the contents of these packages for duplicated files.

Package Along Localization Boundaries

Localization-specific items should be in their own package. An ideal packaging model would have a product's localizations delivered as one package per locale. Unfortunately, in some cases organizational boundaries conflict with the functional and product boundaries criteria.

International defaults can also be delivered in a package. This design isolates the files that are necessary for localization changes and standardizes the delivery format of localization packages.

Image Packaging System (IPS) Packages

This document discusses SVR4 packages. For delivery into the OpenSolaris OS, consider using Image Packaging System (IPS) packages. The OpenSolaris OS supports both SVR4 and IPS packages. The IPS software interacts with network repositories and uses the ZFS file system. In the OpenSolaris OS, you can publish existing SVR4 packages to an IPS repository with the pkgsend(1) command.

The following table contains a comparison of commands for the SVR4 packaging system and the IPS packaging system. For detailed information on IPS, see Getting Started With the Image Packaging System.

Table 1–1 Packaging Tasks: IPS and SVR4

Task	IPS command	SVR4 command
Install a new package	pkg install	pkgadd -a
Display information about a package's state	pkg list	pkginfo
Verify correct installation of a package	pkg verify	pkgchk -v
Display information about a package	pkg info	pkginfo -l
Listing the contents of a package	pkg contents	pkgchk -l
Uninstall a package	pkg uninstall	pkgrm

Packaging Commands, Files, and Scripts

This section describes the commands, files, and scripts that you might use when manipulating packages. They are described in man pages and in detail throughout this book, in relation to the specific task they perform.

The following table shows the commands to help you build, verify, install, and obtain information about a package.

Table 1–2 Packaging Commands

Task	Command/ man Page	Description	For More Information
Create packages	pkgproto(1)	Generates a prototype file for input to the pkgmk command	Example—Creating a prototype File With the pkgproto Command
pkgmk(1)	Creates an installable package	Building a Package
Install, remove, and transfer packages	pkgadd(1M)	Installs a software package onto a system	Installing Software Packages
pkgask(1M)	Stores answers to a request script	Design Rules for request Scripts
pkgtrans(1)	Copies packages onto a distribution medium	Transferring a Package to a Distribution Medium
pkgrm(1M)	Removes a package from a system	Removing a Package
Obtain information about packages	pkgchk(1M)	Verifies the integrity of a software package	Verifying the Integrity of a Package
pkginfo(1)	Displays software package information	The pkginfo Command
pkgparam(1)	Displays package parameter values	The pkgparam Command
Modify installed packages	installf(1M)	Incorporates a new package object into an already installed package	Design Rules for Procedure Scripts and Chapter 5, Case Studies of Package Creation
removef(1M)	Removes a package object from an already installed package	Design Rules for Procedure Scripts

The following table shows the information files that help you build a package.

Table 1–3 Package Information Files

File	Description	For More Information
admin(4)	Package installation defaults file	The Administrative Defaults File
compver(4)	Package compatibility file	Defining Package Dependencies
copyright(4)	Package copyright information file	Writing a Copyright Message
depend(4)	Package dependencies file	Defining Package Dependencies
pkginfo(4)	Package characteristics file	Creating a pkginfo File
pkgmap(4)	Package contents description file	The pkgmap File
prototype(4)	Package information file	Creating a prototype File
space(4)	Package disk space requirements file	Reserving Additional Space on a Target System

The following table describes optional installation scripts that you can write that affect if and how a package is installed.

Table 1–4 Package Installation Scripts

Script	Description	For More Information
request	Solicits information from the installer	Writing a request Script
checkinstall	Gathers file system data	Gathering File System Data With the checkinstall Script
preinstall	Performs any custom installation requirements before class installation	Writing Procedure Scripts
postinstall	Performs any custom installation requirements after all volumes are installed	Writing Procedure Scripts
preremove	Performs any custom removal requirements before class removal	Writing Procedure Scripts
postremove	Performs any custom removal requirements after all classes have been removed	Writing Procedure Scripts
Class action	Performs a series of actions on a specific group of objects	Writing Class Action Scripts