ICS 121: Packaging and Deployment

After a software product is fully developed and tested, it must be packaged so that it can be easily deployed and used.
Packaged code is usually in just one or a few files, rather than hundreds of .class or .o files. The package file is called an "archive".
The package itself adds additional information about the product:
- Product name and version
- Package dependencies: other things that must be installed first
- Sometimes a brief description of the product
- Sometimes contact information for the author or vendor
- Cryptographic signature of author or vendor

Deployment is the process of transfering packaged code to a machine where it will run and installing it.
Deployment may be explicit (e.g., I put a disk in the CDROM drive) or implicit (e.g., I run a program and it checks if an updated version is available then offers to download and install the update).
The correct version of the product must be selected for this environment. Usually the latest version should be found and deployed.
An installer program does the work of installing the pacakged code. Must detect any missing dependent packages. There must be ways to upgrade or uninstall the product. A database of currently installed software must be maintained.
Users only want to deploy authentic products, not trojans or viruses. Must check cryptographic signature.
Licensing verification: how do you really know if the user is licensed to run this software? CD key, product activation, license server.

Jar/War/Ear: Java archive formats. These are just .zip files with some extra files of meta-data.
jarsigner: Java tool to cryptographically sign an archive
RPM: The Redhat Package Manager, a linux file format for software packages.

InstallSheild: Popular installer program generator for Windows
InstallAnywhere: Popular installer program generator for Windows
JavaWebStart: Automatically downloads, installs, upgrades, and runs Java applications when the user clicks on a link.