pyceo/docs/INSTALLING

                    BUILDING AND INSTALLING
                    -----------------------

This document describes the steps needed to get the package built and
installed on CSC systems. If you don't have authority to do this, you
can safely skip it.

If you don't have the required authority, but have a Debian box of your own,
then note that you have all the tools required to replicate our setup
on your own system for testing. Of course, if you are capable of doing
so, you should probably be on the Systems Committee anyway.


Building the Package
--------------------

To build a Debian package out of the sources, run one of the following
commands at the top of the source tree:

    A. debuild
    B. fakeroot dpkg-buildpackage -us -uc
    C. git-buildpackage

It doesn't matter which, so 'debuild' is probably easiest. If all goes well,
a Debian package and source tarball will appear in the parent directory.

Do NOT build the package as root (rather, don't build anything as root in
general). Use 'fakeroot' so that the permissions in the .deb can be set
correctly. It is only necessary to build as root if you are using pbuilder,
which builds in a chroot.

You can examine the package with tools like dpkg-deb(1) and debdiff(1).
One useful command is `dpkg-deb -c <deb-file>`. This will give you a list
of files that will be installed.

If your build is a development build, you can safely delete it (it will
be overwritten anyway if a subsequent build has the same version number).


Installing the Package
----------------------

If you will be installing the package it is essential you follow certain
guidelines in order to avoid overwriting someone else's changes.

I'm assuming that you have made your changes and commited them to your
repository, and that your last test build was successful and you're read to
install the package. Before you install, you need to:

    1. Examine the currently installed package

        Your package should incorporate all of the changes that are in the
        currently installed package. Otherwise you may be installing a
        package that does not include important bug fixes and improvements.

        Since every release has a changelog entry, you can easily check
        that your source tree is up-to-date by comparing your
        debian/changelog with /usr/share/doc/csc/changelog.Debian.gz.
        The zdiff(1) utility is helpful for doing this comparison.

        If your changelog is missing some entries, find the git repository
        of the person who wrote the changelog entry (this will be easy if
        they put a link in /users/git) and pull in their changes. Review
        the changes and merge them into your tree.

    2. Increase the package version number

        Look at the version number of latest entry in debian/changelog.
        Think of a number that is greater than this number and that
        reflects the magnitude of your change. Generally just increase
        last number by one.

        To set the version number of the next build, run `dch -v <version>`
        at the top of your source tree. This will create a new changelog
        entry and open your favorite editor for the next step.

    3. Write a changelog entry for your update

        Step #2 will put you in your favorite text editor. Add some bullets
        that describe all of the changes in the new version. Note that this
        file follows a set format and must be machine readable. If in doubt,
        run `dpkg-parsechangelog` when you're done to see if it complains.

    4. Commit the changelog update to your repository

        For your commit message, mention that that this is a new release
        (include the version number) and copy your summary from the
        changelog.

    5. Build the package

        Use 'debuild' or 'fakeroot dpkg-buildpackage -us -uc' to build the
        package. Do not simply run 'debian/rules binary' as this will
        create the .deb but not the .tar.gz, .dsc, and .changes.

    5. Install the package

        You're finally ready to run `dpkg -i csc_<version>_<arch>.deb`. Do
        this and cross your fingers. Make sure to test ceo a bit to see if
        it still works. If it doesn't, install the previous version and
        investigate the problem. You will probably have to make more
        changes and repeat this whole process.

    6. Archive the package file and source

        You will be left with four files: a .deb, a .tar.gz, a .changes,
        and a .dsc. Save these to a safe place (preferably in /users/git
        so other can find them easily).

If everyone follows these steps, every installed version will be a
descendant of the previous. Further, since old versions are archived it
will be easy to quickly get ceo working again after a bad update.

For the git skeptics: Yes, a central repository would serialize changes
automatically, making sure each is a descendant of the previous. The reason
I don't want to do this is that you have to trust everyone who can commit
not to break anything. With git any random CSC member can fetch the tree
and start making changes without any special permissions. Not that CSC
members are untrustworthy, but in my opinion git lowers the barrier for
potential contributors by giving them immediate write access to a
repository.


Old Versions
------------

It is desirable that old, known-working builds be available to install in
an emergency. So, as described above, please store your release builds in
an easy to find place.

My (Michael Spang's) builds can be found in /users/git/mspang/csc.builds.
They are cryptographically signed (with debsign).

Old source tarballs are stored alongside the debs. To extract them, run
`dpkg-source -x csc_<version>.dsc`. You can use tar, too, but it will
not check for corruption and won't verify the signature.

If the current version is broken and you need to install an old version,
do so, but note that switching between some versions requires changes to
the configuration files (dpkg will bug you about this). For example,
these files changed significantly between versions 0.1 and 0.2. In this case
install the old configuration files and then merge important information
(e.g. passwords) into them from the .dpkg-old file.