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Starting at the top, we start the build with the usual command. Immediately following the command, RPM indicates that four packages are to be built from this spec file. The %prep, %build, and %install scripts then execute as usual.
Next, RPM executes its special doc internal script, even though we haven't declared any files to be documentation. It's worth noting, however, that the DOCDIR environment variables show that if the spec file had declared some of the files as documentation, RPM would have created the appropriate documentation directories for each of the packages.
At this point, RPM creates the binary packages. As you can see, each package contains the file defined in its %files list.
Finally, the source package file is created. It contains the spec file and the original sources, just like any other source package.
One spec file. One set of sources. One build command. Four packages (five, if you count the source package). All in all, a pretty good deal, isn't it?
Let's take a look at our newly created packages. As with any other package, each subpackage should be tested by being installed on a system that has not had that software installed before. In this section, we'll point out how subpackages differ from their nonsubpackaged counterparts.
First, let's just look at each package's information:
# rpm -qip foo-2.7-1.i386.rpm Name : foo Distribution: (none) Version : 2.7 Vendor: (none) Release : 1 Build Date: Wed Nov 06 13:33:37 1996 Install date: (none) Build Host: foonly.rpm.org Group : bogus/junque Source RPM: foo-2.7-1.src.rpm Size : 35 Summary : The foo app, and the baz library needed to build it Description : This is the long description of the foo app, and the baz library needed to build it... # rpm -qip foo-server-2.7-1.i386.rpm Name : foo-server Distribution: (none) Version : 2.7 Vendor: (none) Release : 1 Build Date: Wed Nov 06 13:33:37 1996 Install date: (none) Build Host: foonly.rpm.org Group : bogus/junque Source RPM: foo-2.7-1.src.rpm Size : 42 Summary : The foo server Description : This is the long description for the foo server...
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# rpm -qip foo-client-2.7-1.i386.rpm Name : foo-client Distribution: (none) Version : 2.7 Vendor: (none) Release : 1 Build Date: Wed Nov 06 13:33:37 1996 Install date: (none) Build Host: foonly.rpm.org Group : bogus/junque Source RPM: foo-2.7-1.src.rpm Size : 42 Summary : The foo client Description : This is the long description for the foo client... # rpm -qip bazlib-5.6-1.i386.rpm Name : bazlib Distribution: (none) Version : 5.6 Vendor: (none) Release : 1 Build Date: Wed Nov 06 13:33:37 1996 Install date: (none) Build Host: foonly.rpm.org Group : bogus/junque Source RPM: foo-2.7-1.src.rpm Size : 38 Summary : The baz library Description : This is the long description for the bazlib... #
Here we've used RPM's query capability to display a list of summary information for each package. A few points are worth noting.
First, each package lists foo-2.7-1.src.rpm as its source package file. This is the only way to tell if two package files were created from the same set of sources. Trying to use a package's name as an indicator is futile, as the bazlib package shows us.
The next thing to notice is that the summaries and descriptions for each package are specific to that package. Since these tags were placed and named according to each package, this should be no surprise.
Finally, we can see that each package's version has been either inherited from the main package's preamble or, as in the case of the bazlib package, the main package's version has been overridden by a version tag added to bazlib's preamble.
If we look at the source package's information, we see that its information has been taken entirely from the main package's set of tags:
# rpm -qip foo-2.7-1.src.rpm Name : foo Distribution: (none) Version : 2.7 Vendor: (none) Release : 1 Build Date: Wed Nov 06 13:33:37 1996 Install date: (none) Build Host: foonly.rpm.org Group : bogus/junque Source RPM: (none) Size : 1415 Summary : The foo app, and the baz library needed to build it Description : This is the long description of the foo app, and the baz library needed to build it... #
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It's easy to see that if there were no %files list for the main package, and therefore, no main package, the tags in the main preamble would still be used in the source package. This is why RPM enforces the requirement that the main preamble contain copyright, %description, and group tags. So, here's a word to the wise: Don't put something stupid in the main preamble's %description just to satisfy RPM. Your witty saying will be immortalized for all time in every source package you distribute. (Yes, the author found out about this the hard way!)
The easiest way to verify that the %pre scripts we defined for each package were actually used is to simply install each package:
# rpm -Uvh foo-2.7-1.i386.rpm foo This is the foo package preinstall script ################################################## # rpm -Uvh foo-server-2.7-1.i386.rpm foo-server This is the foo-server subpackage preinstall script ################################################## # rpm -Uvh foo-client-2.7-1.i386.rpm foo-client This is the foo-client subpackage preinstall script ################################################## # rpm -Uvh bazlib-5.6-1.i386.rpm bazlib This is the bazlib subpackage preinstall script ################################################## #
As expected, the unique %pre script for each package has been included. Of course, if we hadn't wanted to actually install the packages, we could have used RPM's --scripts option to display the scripts:
# rpm -qp --scripts foo-2.7-1.i386.rpm preinstall script: echo "This is the foo-server subpackage preinstall script" postinstall script: (none) preuninstall script: (none) postuninstall script: (none) verify script: (none) #
This approach might be a bit safer, particularly if installing the newly built package would disrupt operations on your build system.