[ic] Interchange + CVS HOWTO: First release
Dan Browning
interchange-users@lists.akopia.com
Thu Jul 19 22:36:00 2001
After a 2 month hiatus, I've finally made good on my offer to write a
"Interchange + CVS HOWTO." Although I'm not a technical writer by nature,
I hope that the quality is good enough to be useful to some (patches to
ic_cvs.sdf welcome).
Even if you aren't using CVS as part of your development now, or don't
think you need CVS, you might consider reading this document anyway. You
might find CVS to be indispensable after using it. I also highlighted a
few development tips in the "Tools of the trade" section that I have found
useful over the last year or so of developing IC.
Further, I hope that this selfless act of a humble (yeah right), lowly
interchange developer might strike some as an inspiration to write IC
documentation themselves.
Jon/Mike: You'll notice the attached .sdf was written in Interchange SDF
style, so if you would like to fitly join this document into the standard
IC docs I can oblige with whatever refinements and fixes are
recommended. (Of course, that doesn't apply if you think this HOWTO is as
ugly as sin to start with).
What follows is a cut and paste of the text version, with HTML, PDF, and
SDF formats attached. If I have broken the cardinal rule on message size,
may I be publicly chastised by the list for the amount of time it takes to
download on a 28.8 modem.
Respectfully,
Dan Browning, Cyclone Computer Systems, danb@cyclonecomputers.com
Interchange + CVS HOWTO
=======================
ic_cvs.1.00 (Draft)
1. Introduction
===============
1.1. Preamble
-------------
Copyright 2001 Dan Browning <danpb@mail.com>. This document is freely
redistributable under terms of the GNU General Public License.
1.2. Purpose
------------
The purpose of this document is to help others take advantage of CVS
and Interchange together to increase the quality of their programming,
whether they are sole developers or part of a large team of
programmers, graphic artists, and HTML design gurus. Portions of it
apply to general CVS setup and use, but it is geared toward the
average developer using Interchange to implement an e-commerce
website.
1.3. Audience
-------------
I intend for this document to be useful to those who are not yet
familiar with CVS as well as those who are. If you already know how
to setup a pserver then you might just skim chapter 2 ("Setup CVS"),
or just skip it all together.
In addition, I have tried to write at a technical level that would be
on par with what I percieve to be the average Interchange user that
participates in the interchange-users mailing list. It is assumed
that the reader can and has setup Interchange and the foundation (or
construct) template catalog is working correctly.
1.4. Contact the author
-----------------------
If you find any spelling errors, technical slipups, mistakes,
subliminal messages, or if you wish to send feedback, critique,
remarks, comments, or if you wish to contribute examples, instructions
for alternative platforms, chapters, or other material, please do so.
The preferred method of submitting these changes is in the form of a
context diff against the SDF source file (ic_cvs.sdf). Please address
your correspondence to:
Dan Browning danpb@mail.com
1.5. The advantages of using CVS
--------------------------------
CVS is a very useful tool and can help you in your development, no
matter if you are one developer or are coordinating a team of
developers.
o What is CVS all about?
o What are it's advantages?
The official CVS website (http://www.cvshome.org/new_users.html) has
more detailed answers to these questions, but here are some brief
points of interest.
o Checkout "historic" points in time or milestones in a project,
for example when an e-commerce site went "live" or before a major
branch in the code.
o Revert to older versions of a file, directory, or an entire
website.
o Branching releases. Concurrently develop an unstable development
version as well as fix bugs in the stable production version.
o Multiple developers can work on the same catalog and even the
same file at the same time. (For more information about how
multiple simultaneous writes are merged and conflicts resolved,
see the cvs docs in the Resources Appendix).
o CVS is better than ftp for file transfer, because it
automatically downloads only changed files, and even then, only
the portion of the file that has changed (using patches).
o CVS can automatically merge two simultaneous writes to the same
file by different developers.
o Allows one to keep track of the changes that have been made over
time (many release managers repackage cvs commit logs into
WHATSNEW, HISTORY, and/or NEWS files).
1.6. How to use this document
-----------------------------
There are many potential uses of CVS as it applies to Interchange. In
fact, there are as many unique ways to use CVS as there are unique
developers. This document can only cover some of the ways, including
basic and useful techniques to get started using CVS. For the intents
of the average web developer using IC for a B2C e-commerce site, I've
identified a few of the possible uses:
Simple
o One server
o One catalog
o One cvs module
o One branch
Medium
o One server
o Two catalogs (one is live, one is development)
o One cvs modules
o Seperate development and live branches
Complex/Custom
o Multiple servers (e.g., developers' servers, staging servers, and
live servers)
o Multiple catalogs
o Multiple cvs modules
o Multiple branches
o Custom setup
This document attempts to cover the Simple well, explain many aspects
of the Medium, which will hopefully give you the background you need
if you decide to setup your own complex development environment.
2. Setup CVS
============
2.1. Assumptions
----------------
Here are some of the assumptions that I make that apply to various
parts of the rest of this document:
o Red Hat 7.x
o Interchange installed (RPM, tarball, or CVS)
o Default interchange tarball directory paths (adjust for your
environment)
o foundation catalog setup and working
Note: I will assume "foundation" for the catalog name and directory
paths, but it should be just as easy to use this document with the
construct catalog or your own catalog by mentally transposing the
names and paths.
There shouldn't be any reason why you could not do everything I
mention here on other Linux distributions, unicies or cygwin.
However, my statements will reflect Red Hat 7.x. Additionally, Red
Hat 6.x is for the most part the same as 7.x, except for the
difference of using inetd instead of xinetd to setup pserver.
2.2. Installing CVS
-------------------
This is the easy part. For Red Hat systems, download the cvs rpm's
and install them. The following RPM command will download and install
the Red Hat 7.1 version of cvs from rpmfind.net.
Note: You need to be root to complete the following tasks
su - root
rpm -Uvh
ftp://speakeasy.rpmfind.net/linux/redhat/7.1/en/os/i386/RedHat/RPMS/cvs-1.11-3.i386.rpm
Create the user and group that will administrate the interchange
repository. For this document, it will be the interch user, (which
has already been created by the RPM installation, if you use that).
But if you understand the mechanics of Unix users/groups, then you can
use whatever username and group scheme you prefer. For example, some
create a cvs user and cvs group, then add the interchange user and
catalog owner to it's group and/or vise-versa. The integration of
interchange and CVS in the latter portion of this document will
require that the CVS user has some write capability to the catalog
directory.
2.3. Create the CVS repository directory
----------------------------------------
You will need to create a repository directory such as /rep, which is
used here and in the rest of the document, but it can be any directory
you desire, and must be owned by the cvs user. Many use /var/rep or
/home/cvs/rep.
su - root
mkdir /rep
chown interch.interch /rep
2.4. Setup environment variables
--------------------------------
The CVSROOT and EDITOR environment variables should be setup for all
users in /etc/profile. Of course, EDITOR can be whatever Unix text
editor you prefer, such as vi, emacs, pico, or joe.
/etc/profile:
export CVSROOT=/rep
export EDITOR=vi
Note: You will need to logout/login for the profile changes to take
effect.
2.5. Initialize the repository
------------------------------
Initialize the repository as the CVS user, which is interch for this
document.
su - interch
cvs -d /rep init
2.6. CVS Authentication
-----------------------
2.6.1. Background
-----------------
Authentication is done in CVS through the $CVSROOT/CVSROOT/passwd
file. It can be easily manipulated through some of the CVS
administration tools that are available.
2.6.2. CVS administration tools
-------------------------------
o http://freshmeat.net/projects/cvsadmin/
o http://freshmeat.net/projects/cvspadm/
I recommend cvsadmin, but there is also a manual method that can be
used in the absence of such tools, which involves copying the system
shadow file and modifying it for use by CVS. For more information on
the manual method, see the RedHat CVS pserver setup guide by Michael
Amorose (http://www.michael-amorose.com/cvs/).
2.6.3. Setup authentication using the cvsadmin tool
---------------------------------------------------
You can find a tarball to install on your system using the above
address, but here is the address of a recent RPM package of the
version. This package is intended for mandrake systems, but is
compatible with Red Hat 7.1:
o
ftp://speakeasy.rpmfind.net/linux/Mandrake-devel/contrib/RPMS/cvsadmin-1.0.1-1mdk.i586.rpm
After installing, create a password file (touch
$CVSROOT/CVSROOT/passwd), and execute cvsadmin add <usernames> for
each of your usernames.
2.7. Setup CVS modules
----------------------
Note: From this point on, assume that all commands are executed as the
CVS user (e.g. interch), unless otherwise specified.
A module is CVS is like the concept of a "project", where each module
has its own branches, trees, and other features.
2.7.1. Add your project to modules
----------------------------------
The format of the modules file is explained in detail in the cvs
documentation, here is the simplest way to use it:
/rep/CVSROOT/modules:
<Module name><TAB><Module Directory>
The module name can be whatever you want, and the module directory is
what we will create later under /rep. We'll want a module for the
template catalog (foundation). For example:
foundation foundation
2.7.2. Create the module directory
----------------------------------
This is the directory that is referred to in the CVSROOT/modules file
we just modified.
mkdir /rep/foundation
2.8. Setup binary file types
----------------------------
This isn't necessary if you aren't going to manage any binary files
(e.g. if you plan on excluding your /images/ directory). But I
recommend including it. The following is an example including many
binary file types (by extension) used in web development.
/rep/CVSROOT/cvswrappers:
*.avi -k 'b' -m 'COPY'
*.doc -k 'b' -m 'COPY'
*.exe -k 'b' -m 'COPY'
*.gif -k 'b' -m 'COPY'
*.gz -k 'b' -m 'COPY'
*.hqx -k 'b' -m 'COPY'
*.jar -k 'b' -m 'COPY'
*.jpeg -k 'b' -m 'COPY'
*.jpg -k 'b' -m 'COPY'
*.mov -k 'b' -m 'COPY'
*.mpg -k 'b' -m 'COPY'
*.pdf -k 'b' -m 'COPY'
*.png -k 'b' -m 'COPY'
*.ppt -k 'b' -m 'COPY'
*.sit -k 'b' -m 'COPY'
*.swf -k 'b' -m 'COPY'
*.tar -k 'b' -m 'COPY'
*.tgz -k 'b' -m 'COPY'
*.tif -k 'b' -m 'COPY'
*.tiff -k 'b' -m 'COPY'
*.xbm -k 'b' -m 'COPY'
*.xls -k 'b' -m 'COPY'
*.zip -k 'b' -m 'COPY'
2.9. Testing your repository
----------------------------
At this point, you should have a working (though empty) CVS
repository. Before we continue with setting up the pserver or
importing source code, try logging in as one of the cvs users listed
in your CVSROOT/passwd and test the checkout.
#test checkout in home directory of any cvs user
mkdir ~/src
cd ~/src
cvs co foundation
This should create foundation/ and foundation/CVS.
2.10. Setup the CVS pserver
---------------------------
You will likely need to be root to do this, and there are lots of
guides on the internet for setting up a cvs pserver, hopefully you
wont have any trouble doing it on your particular operating system.
See the Resources Appendix for more information.
2.10.1. Setup pserver in Red Hat 7.1 using xinetd.
--------------------------------------------------
For Red Hat 7.x, edit /etc/xinetd.d/cvspserver (create a new one if
none exists). The following works for me, but customization may be
required for your environment (see the next section below for an
inetd-based system example). This also must be done as root.
su - root
/etc/xinetd.d/cvspserver:
# default: on
service cvspserver
{
disable = no
socket_type = stream
protocol = tcp
wait = no
user = root
server = /usr/bin/cvs
server_args = -f --allow-root=/rep pserver
}
Also unset the HOME variable in xinetd. This was required for my
repository to work correctly, but if anyone has a better suggestion, I
would appreciate a note.
/etc/xinetd.d/cvspserver:
unset HOME
Now, restart xinetd for the changes to take effect.
service xinetd restart
2.10.2. Setup pserver in inetd-based systems.
---------------------------------------------
I haven't tested this (any takers?), but something like the following
needs to be done for inetd-based systems such as Red Hat 6.2. Make
sure that the following files are setup accordingly.
/etc/services:
cvspserver 2401/tcp
N:/etc/inetd.conf:
cvspserver stream tcp nowait root /usr/sbin/tcpd /usr/local/bin/cvs
--allow-root=/usr/local/newrepos pserver
2.10.3. Testing your pserver
----------------------------
At this point, you should be able to use a cvs client to use your
pserver and execute all the same commands that you can locally (which
we tested before). You may wish to take advantage of a graphical cvs
client, which can be particularly helpful in leveling the learning
curve.
See the Resources Appendix for links to some graphical CVS tools.
3. Import your Interchange catalog into CVS
===========================================
3.1. Configuring your catalog
-----------------------------
Eventually, we will import your catalog into the cvs repository, but
first we need to do some work with a temporary copy of the catalog so
we can get it into shape for importing.
Note: From here on, assume the use of the interchange user, such as
interch, unless otherwise noted.
su - interch
If you installed via RPM:
service interchange stop
If you installed via tarball (default path):
/usr/local/interchange/bin/interchange --stop
3.2. Remove old CVS folders
---------------------------
If, for any reason, you already have CVS files (all the CVS/
directories)in your catalog, they must be removed because they might
interfere with the new CVS setup. For example, maybe you moved
servers and you are setting up CVS again. You might use the following
find command, which will find any folders named CVS in the current
directory and remove them. There is probably a better way to deal
with old CVS/ folders, but the following works for me (again,
suggestions welcome).
Note: You should make a backup of the catalog directory before you do
this.
#Become interchange catalog user
su - interch
#backup catalog folder first
tar czf ~/foundation_backup.tgz /var/.../foundation
#get rid of any old CVS folders -- (BE CAREFULL!)
cd /var/lib/interchange/foundation
find . -name CVS -exec rm -Rf {} \;
3.3. Create a working copy of your catalog
------------------------------------------
A working copy of your catalog is necessary to get it into shape for
use with CVS. The following command creates a copy in the /tmp
directory.
cp -a /var/lib/interchange/catalogs/foundation /tmp/import_foundation
cd /tmp/import_foundation
3.4. Streamline your catalog for CVS
------------------------------------
3.4.1. Considerations about what to import into CVS
---------------------------------------------------
From your working directory (/tmp/import_foundation), decide what
pages will be in the CVS repository, and which will not. While it is
entirely possible to import the entire catalog into the repository
unchanged, I usually prefer to doctor my directories up before letting
them into my repository for several reasons:
o Will the file be modified by another source?
For example, /etc/order.number is modified by interchange when run.
But not everyone will use a local development model that includes
running interchange on a directly checked-out copy of their source.
Which means this specific issue is avoided if you upload every edit
before viewing your changes on a server.
o The likelihood that you will modify the file.
For example, if I am certain that I wont every want to modify the
session/ files directly, then I probably wouldn't need to manage that
through CVS, but I do import the empty session/ directory to make it
easier when setting up new catalogs.
o Speed.
Managing less files in the repository takes away from the amount of
time required for cvs checkout, update, branching, and other cvs
actions. For most, this amount of time is small already, but it is a
consideration for some.
o Ease of use.
One reason NOT to remove anything from your catalog before importing
is it creates the ability to have a completely working catalog from
just one checkout (much like the CVS tree at interchange.redhat.com).
Whereas if you leave out other directories like etc/ session/ orders/,
etc., then you must first combine your checkout with the other working
parts of a catalog before the catalog is viable. But this is slower
and will bring up lots of harmless notification and warning messages
(about changed local versions) if you run interchange on your local
source copy (because interchange will touch etc/ session/ orders/,
etc. directly, and then warn that your local copy has changed from the
CVS copy). You may be able to manage some of these notifications and
warnings with CVSROOT/cvsignore or $CVSIGNORE, see the Resources
appendix for more details.
3.4.2. Remove files that aren't needed in CVS
---------------------------------------------
Here is an example of some directories to remove. If you do move more
directories, be sure to move them to a directory that you can later
use to re-unite with a checked-out copy for a working catalog. But
here I chose just to move files that are not needed for a template
"skeleton" catalog.
The images directory is typically symlinked to
/var/www/html/foundation/images, so I remove this symlink from the
working copy, and replace it with an exact copy which will go into the
CVS repository.
cd /tmp/import_foundation
mkdir /tmp/import_foundation_nonCVS
#Setup images directory
rm images
cp -a /var/www/html/foundation/images .
#Remove
mv error.log logs/* orders/* session/* tmp/* upload/* \
/tmp/import_foundation_nonCVS
3.5. Import the streamlined catalog
-----------------------------------
Import the remaining portion of the catalog using the cvs import
command, with "foundation" as the module name and repository directory
name. See the CVS documentation resources mentioned in Appendix
Resources for more information.
When you run the import command, it will launch $EDITOR (set to 'vi'
earlier), and ask for a message to go along with the import action.
Whatever you see fit to write (e.g. "starting new cvs module with my
foundation catalog...") is fine.
This example import command includes renaming the foundation "working"
directory back to "foundation" for the import.
su - interch
cd /tmp/import_foundation
cvs import foundation foundation start
3.6. Testing the new CVS module
-------------------------------
Now you should be able to do another test checkout or update using any
CVS client, which should now download all the files that you have just
imported into CVS. Additionally, you might test making a change to
one of your checked-out source files, saving it, then committing it.
index.html:
<!--this is a test comment at the top of index.html-->
Now commit the change
cvs commit index.html
Your changed version will now be resident in the repository. There
are a lot of good CVS documentation and resources for discovering more
about the checkout/update/commit cycle and other CVS aspects in the
Resources Appendix.
You'll also notice that even if you start your interchange server, the
change you made did not take effect. The next section will detail the
process of tying CVS and Interchange together in a way that this will
happen automatically.
4. Integrate CVS and Interchange
================================
The next step is to allow CVS to update the directory that Interchange
uses to serve pages.
4.1. CVS checkout into the catalog directory
--------------------------------------------
Now it is the time to replace the directories in your catalog that
have counterparts in CVS with fresh checkouts from CVS (this is a
preliminary action to allow CVS to update your catalog directory when
a change is made to CVS).
Note: Make sure interchange daemon is stopped and you have a good
backup before continuing.
tar czf ~/foundation.backup2.tgz /var/lib/interchange/foundation
Checkout a copy from CVS into a different directory (such as
foundation_CVS).
cd /var/lib/interchange/
cvs co -d foundation_CVS foundation
This should create the foundation_CVS/ directory for you, so that it
wont conflict with your existing foundation/ directory.
4.1.1. Add any needed files to checked-out catalog
--------------------------------------------------
If you removed any directories during the streamlining step, we must
first add those back so that the catalog is usable to Interchange. In
this document, we only removed files within the directories that
weren't needed.
This can also be the time to copy any "data" files such as orders/
logs/, etc. that might be needed if it is a live catalog.
cd /var/lib/interchange/foundation
cp -a <NEEDED_FILES> \
/var/lib/interchange/foundation_CVS
4.1.2. Install and test the new catalog
---------------------------------------
Now lets move the old foundation out of the way and put the new
foundation_CVS in its place.
cd /var/lib/interchange/
mv foundation foundation_old
mv foundation_CVS foundation
Now, link up the CVS images for use by Apache.
cd /var/www/html/foundation/
mv images images_old
ln -s /var/lib/interchange/foundation/images images
Now, you should have a working catalog again. To make sure, start up
interchange and test the site with your browser.
4.2. Testing manual CVS updates on Interchange catalogs
-------------------------------------------------------
Next, lets again update the checkout we made a while back before
importing our catalog. (Alternatively, one could use a visual CVS
client detailed above).
cd ~/src
cvs -q up -d foundation # -q for quiet, -d for directory prune/update
Additionally, you might test making a change to one of your
checked-out source files, saving it, then committing it.
index.html:
<!--this is a test comment at the top of index.html-->
Now commit the change
cvs commit index.html
Your changed version will now be resident in the repository. Again,
CVS documentation is in the Resources Appendix.
This time, we can allow the changes to take effect on the code being
used by interchange to server pages. To do so, one must run a cvs
update on the catalog directory:
cd /var/lib/interchange/foundation
cvs -q up -d #up is the shortened version of "update"
That should notify you of the new version it downloaded with something
like:
U pages/index.html
You may also get something like the following:
M catalog.cfg
M etc/status.foundation
M ...
? orders/000001
? ...
The ? lines in the above example mean that the CVS server has never
heard of the listed directories or files (they are in your local
source dir but not in the CVS source dir). It is harmless, but
sometimes annoying.
The M means that sthe file has been modified on your local copy, and
is out of sync with the remote CVS version (e.g. when Interchange runs
it updates etc/status.foundation). Normally this is corrected by
uploading your "modified" version to the server, but in this case, the
modification was done by Interchange instead of the programmer, and
wasn't meant to be committed back to the CVS repository. These types
of messages can be handled with $CVSIGNORE and
$CVSROOT/CVSROOT/cvsignore.
Now, check to make sure that your change has taken effect by
refreshing the homepage on the site. To see the comment, use
View->Page Source or whatever the relevant command for your browser
is.
At this point, its obvious that it would be time consuming to manually
run 'cvs up' every time you make a change to the source code, so the
next step is to setup CVS to automatically update the catalog whenever
you commit something to CVS.
4.3. Automatic updates on commit
--------------------------------
Start by modifying $CVSROOT/CVSROOT/loginfo
^foundation (date; cat; (sleep 1; cd /var/lib/interchange/foundation;
cvs -q update -d) &) >> $CVSROOT/CVSROOT/updatelog 2>&1
The first line tells cvs that for every commit on modules that start
with "foundation" (notice the regular expression "^foundation"), it
will run cvs update on the given catalog directory in the background.
It is important that it is executed in a forked shell (notice the "&")
after sleep'ing for 1 second, because otherwise you may run into
contention issues that can cause file locking problems. The 1 second
timing used above works fine for me, but a longer pause may be
necessary for slower computers (you'll know if you get errors about
"such-and-such locked by user so-and-so"). See the CVS documentation
in the Resources Appendix for more details.
4.4. Automatic e-mail on commit
-------------------------------
Often it is very helpful to have a commit mailing list that keeps
developers up-to-date on every commit happening to the CVS. To setup
automatic e-mails on every commit, put the following in
/rep/CVSROOT/loginfo:
ALL /usr/bin/cvs-log $CVSROOT/CVSROOT/commitlog $USER "%{sVv}"
This tells CVS to pipe the commit output to a shell script, which in
turn updates a log file and e-mails an update (typically to a mailing
list address). Create the shell script at /usr/bin/cvs-log that is
executable by the cvs user (using "chmod 755 /usr/bin/cvs-log").
/usr/bin/cvs-log:
#!/bin/sh
(echo "----------------------------------------------";
echo -n $2" ";
date;
echo;
cat) | tee $1 | /usr/bin/Mail -s "[foundation-cvs] $3"
foundation-cvs@example.com
Your commit logs will now be archived in the CVSROOT/commitlog file,
and e-mailed to the foundation-cvs@example.com address (of course,
you would need to install a mailing list first). Here is what a
sample e-mail looks like:
Subject: [foundation-cvs] 'directory/subdirectory filename.c,1.7,1.8'
----------------------------------------------
cvs Fri Mar 16 21:14:09 PST 2001
Update of directory/subdirectory
In directory cvs.foundationsomething.com:/tmp/cvs-serv7721
Modified Files:
filename.c
Log Message:
test
Now you have a working CVS development system. At this point it may
be valuable to learn more about CVS the client tools that you are
using.
5. The two track model: development and live catalogs
=====================================================
It is often very valuable to have a two-track development model that
separates the classes of work into separate timing and decision
categories. Some use "staging" and "production" terminology, others
prefer "unstable" and "stable", "beta" and "release", or "development"
and "live".
The easiest starting point for two-track development is to just use
two completely separate CVS modules and catalogs. This can make a lot
of sense for many situations, for example when the next revision of
the site will be so different that it is almost starting from ground
zero.
A slightly more complicated solution is to use the CVS branches
feature. It is more difficult to set up, but can be rewarding when
used correctly.
5.1. When to branch
-------------------
The first decision is when to branch the source code. For websites,
this can sometimes be an easy decision like "first went live", or
"site-wide overhaul", etc.
5.2. Which way to branch
------------------------
There are many different ways to branch source code. What seems to be
the most common method is to use the HEAD (which is the default CVS
mode of "no tag") as the development version, and then make a branch
when a stable release is to be made.
That model doesn't fit my development style at the current time, so I
use the HEAD default branch as my stable live version, and use other
tags (like DEV1 and DEV_REALLY_UNSTABLE) for my development. You will
probably find a method that fits your particular style as you learn
more about CVS.
You will probably find that you are merging (or "folding") most or all
of your development branch back into your stable branch frequently.
This is because unlike traditional programming where products are
launched every two or three years with new features, web sites often
have little fixes and new features added every day or every few weeks,
with new "releases" happening constantly (though not all web sites
follow that trend). The flexibility is there to branch the source for
quite some time to work on a very complex feature or complete redesign
before bringing it to the live site.
Additionally, I prefer to not create a new branch every time I merge,
though some do not mind the overhead.
5.3. Performing the branch
--------------------------
To perform the branch use the cvs tag -b <BRANCH NAME> command. For
example:
cvs tag -b DEV1
Remember that this does not change your locally checked out working
directory to the new tag automatically, it only creates the branch
within the CVS repository.
5.4. Setup the development catalog
----------------------------------
Now we have a branch in CVS, but we need to tie it to something in the
real world, namely, an Interchange catalog.
5.4.1. Importing the catalog
----------------------------
Like we did in Integrating CVS with Interchange, you must make another
copy of your catalog for use as the development version. Some would
like to keep the orders/, logs/, and other directories the same, but I
prefer to start with a clean slate, especially since I don't plan on
having any customers visit the development site. (In fact, you can
restrict who can access the development URL using the Apache
<Directory> allow from... directive).
5.4.1.1. Checkout source code
-----------------------------
cd /var/lib/interchange
cvs co -d foundation_dev foundation
5.4.1.2. Copy any other needed directories to complete the catalog
------------------------------------------------------------------
Depending on how complete your catalog is in CVS, you may need to
create or copy directories/files.
cd /var/lib/interchange/foundation
cp -a catalog.cfg orders/* \
/var/lib/interchange/foundation_dev
Note: A lot of the following steps are performed by the
/usr/local/interchange/bin/makecat script, but here is how to do it
manually:
5.4.2. Setting up a separate database
-------------------------------------
Most often, I find it profitable to make use of a second database for
the development catalog, rather than having both catalogs reference
the same database (especially if the first catalog is live).
5.4.2.1. Create a second database
---------------------------------
Use the means of your database platform to create a separate database.
For example, PostgreSQL users might do something like:
createdb foundation_dev
5.4.2.2. Populate the database
------------------------------
You can rely on the catalogs internal products/*.txt data to generate
the database tables and populate them, or you can export another
catalog's database and import it for the development catalog, like the
example below for PostgreSQL users.
pg_dump foundation > ~/foundation.dump
psql foundation_dev < ~/foundation.dump
5.4.3. Copy the catalog support files
-------------------------------------
#Must be root
su - root
#Copy HTML
cd /var/www/html/
cp -a foundation foundation_dev
#Copy CGI
cd /var/www/cgi-bin
cp -a foundation foundation_dev
5.4.4. Configure the Interchange daemon
---------------------------------------
Many development catalogs will branch at the same time that they
upgrade to a new Interchange daemon version. But for whatever
interchange daemon version you use, perform the necessary
modifications to interchange.cfg. For example:
/usr/local/interchange/interchange.cfg:
Catalog foundation /var/lib/interchange/foundation /cgi-bin/foundation
Catalog foundation_dev /var/lib/interchange/foundation_dev
/cgi-bin/foundation_dev
5.4.5. Configure the catalog specifics
--------------------------------------
The development catalog will differ at least a little bit from the
standard catalog, such as in the CGI_URL and database parameters. You
can also modify/add the foundation_dev/variable.txt instead of the
following.
/var/lib/interchange/catalog.cfg:
Variable CGI_URL /cgi-bin/foundation_dev
Variable IMAGE_DIR /foundation_dev/images
Variable SQLDSN dbi:Pg:dbname=foundation_dev
Variable SQLDB foundation_dev
Now you can restart interchange to make your changes take effect.
5.5. Splitting updates on commit by tag
---------------------------------------
Setup CVS so that when you commit to the DEV1 branch, only the
development (foundation_dev) catalog will be updated. And when you
commit with no tags (HEAD branch), the live (foundation) catalog will
be updated. Here is an example loginfo. Note the -r DEV1 used in the
cvs update command on the development catalog. This isn't strictly
necessary, but it ensures that the right branch is used every time.
$CVSROOT/CVSROOT/loginfo:
^foundation (date; cat; (sleep 1; cd
/var/lib/interchange/foundation_dev; cvs -q up -d -r DEV1; cd
/var/lib/interchange/foundation; cvs -q up -d) &) >>
$CVSROOT/CVSROOT/updatelog 2>&1
ALL /usr/bin/cvs-log $CVSROOT/CVSROOT/commitlog $USER "%{sVv}"
5.6. Using new branches
-----------------------
To use your new branch, checkout a working copy of the source with the
correct tag specified. For example:
cvs co -P -r DEV1
Then make change to one of the files, and commit it. The change
should show on your development catalog, but not your live catalog.
5.7. Merging
------------
When you want to merge a change that you have made on your development
branch into your stable branch, there are many ways that you can do
it. One would be to :
o Make a change in the development branch (DEV1) and commit
it.
o Copy the development-tagged file to a temporary name
o Update to the live version (HEAD)
o Overwrite the live (HEAD) version of the file with your
temporary one
o Commit the result
o Update back to the development version (DEV1)
I do the above so often that I have written a TCL script for WinCVS
that will automatically perform the above steps. And similar shell
scripts can probably be easily written to match your development
environment.
The above seems to be the easiest way, to me. However, there are
other alternatives detailed in the CVS manual in chapter 5, "Branching
and merging", that I highly recommend for reading. One method
involves specifying the last version that has already been merged into
the live branch using a specific version number, date, relative time,
or special purpose tag.
6. Tools of the trade
=====================
This is the productivity tips section, which will hopefully help you
to be able to get more done in less time.
6.1. Workstation interchange installation
-----------------------------------------
Not all developers work on Linux workstations, many use Apples
(graphics designers / html gurus tend too, I've found), and many use
Windows. This means that many developers have the extra step of
uploading their changes to an FTP server or CVS server every time they
make a change.
The remedy to that is to setup an interchange server on your
workstation, or any location that has direct access to the CVS source
files. I'll explain:
The interchange server that runs where the CVS server is (that we
setup earlier) can be seen as the gathering point for all the
developers. However, each developer may run as many interchange
daemons as he/she requires in a local context for the purpose of
seeing the changes made before uploading them via CVS.
For example, Bob could setup another interchange catalog on the same
server as the CVS, (e.g. foundation-bob). To get direct access to
those files (rather than FTP), Bob could use NFS mounts (if Bob's
workstation is Linux) or SMB mounts using Samba if his workstation is
a Windows variant. Any way that Bob can get direct access to the
files will save him some time (by cutting out the "upload" from the
"edit->upload->test" development cycle). One could even use Vmware to
run a Linux server on your Windows workstation.
Note: You can now use the cygwin compatibility confirmed in later
Interchange versions to run Interchange right on your Windows
workstation.
The result will be that you can modify the files with your favorite
text editor and see the results immediately through your local
catalog. Setting up the catalog initially is quite easy. Just follow
the same steps used to setup the CVS catalog. Which is:
o Stop interchange.
o bin/makecat a new catalog.
o Checkout from CVS into a new CVS catalog directory and link the
images/ directory.
o Move any needed files back into the CVS catalog directory.
o Make modifications to products/variable.txt and catalog.cfg (e.g.
CGI_URL, HOSTNAME, DBI_USER, DBI_PASSWORD).
o Restart interchange.
One aspect of this local configuration is managing the differences
between the main interchange daemon which runs on the CVS server and
the local interchange daemon. The differences are probably hostname,
database information, etc. That will all need to be managed (usually
through catalog.cfg entries) and database exports & imports (i.e. the
postgres pg_dump command).
Another thing that you might have noticed at this point is all the
files that are modified locally by the interchange daemon will report
? or M when you run an update. This can be handled with
CVSROOT/cvsignore and $CVSIGNORE, which are beyond the scope of this
document.
6.2. Mailserver for CVS updates
-------------------------------
To setup a mailserver for CVS updates, first download and install
mailman. For Red Hat systems, the following RPM could be used:
o
ftp://speakeasy.rpmfind.net/linux/redhat/7.1/en/powertools/i386/RedHat/RPMS//mailman-2.0.1-2.i386.rpm
After installing, read the following information about Mailman and
what needs to be done after installation (taken from the RPM meta
data):
"Mailman is software to help manage email discussion lists, much like
Majordomo and Smartmail. Unlike most similar products, Mailman gives
each mailing list a web page, and allows users to subscribe,
unsubscribe, etc. over the web. Even the list manager can administer
his or her list entirely from the web. Mailman also integrates most
things people want to do with mailing lists, including archiving, mail
<-> news gateways, and so on.
When the package has finished installing, you will need to:
o Run /var/mailman/bin/mmsitepass to set the mailman administrator
password.
o Edit /var/mailman/Mailman/mm_cfg.py to customize mailman's
configuration for your site.
o Modify the sendmail configuration to ensure that it is running
and accepting connections from the outside world (to ensure that
it runs, set "DAEMON=yes" in /etc/sysconfig/sendmail, ensuring
that it accepts connections from the outside world may require
modifying /etc/mail/sendmail.mc and regenerating sendmail.cf),
and
o Add these lines:
ScriptAlias /mailman/ /var/mailman/cgi-bin/
Alias /pipermail/ /var/mailman/archives/public/
<Directory /var/mailman/archives>
Options +FollowSymlinks
</Directory>
to /etc/httpd/conf/httpd.conf to configure your web server.
Users upgrading from previous releases of this package may need to
move their data or adjust the configuration files to point to the
locations where their data is."
Then run /var/mailman/bin/newlist and follow the directions from
there.
6.3. Locally mapped source code for a network IC server
-------------------------------------------------------
This is useful mostly to Windows users, since Linux users can just as
easily run IC daemons on their own workstation as they can a separate
server.
The idea is to have the IC server use its own files and directories
for things that won't be edited and modified locally, but reference a
samba directory or NFS directory for things that will (such as pages/,
templates/, etc.).
6.3.1. Mount the samba or NFS directory
---------------------------------------
smbmount <...> or mount -t nfsfs <...>
The following script uses two directories (source and destination) to
create symlinks for the commonly modified source directories of
Interchange.
export S=/mnt/nfs/foundation
export D=/var/lib/interchange/foundation
F=db; ln -s $S/$F $D/$F
F=dbconf; ln -s $S/$F $D/$F
F=etc; ln -s $S/$F $D/$F
F=images; ln -s $S/$F $D/$F
F=pages; ln -s $S/$F $D/$F
F=special_pages; ln -s $S/$F $D/$F
F=templates; ln -s $S/$F $D/$F
This will leave you with a working catalog that can be quickly
modified (since your editor can access the local copy), while
interchange has to do the work of going over the SMB or NFS
connection.
6.4. jEdit - a good editor with Interchange/HTML/perl colorization and CVS
--------------------------------------------------------------------------
I have been quite impressed with jEdit (http://www.jedit.org, and open
source editor that is written in java and runs on most platforms.
I use the interchange.xml language definition written by Chris
Jesseman chris@sitemajic.net, which is available from
http://www.sitemajic.net/jedit/. With this, jEdit automatically
colors HTML, perl, AND many interchange tags very intelligently.
Further, jEdit has a CVS plugin, written by Ben Sarsgard
bsarsgard@vmtllc.com, and available at:
http://www.vmtllc.com/~bsarsgard/jedit.html. This plugin allows you
to diff, update, and commit right from the editor.
6.5. Seperate servers for development and live catalogs
-------------------------------------------------------
If you have the luxury of seperate server ardware for the development
and live catalogs, you might find the following utility helpful:
o CVSviaFTP (http://www.cvshome.org/dev/addoncvsftp.html) - from
the CVS Add-ons page (http://www.cvshome.org/dev/addons.html).
It allows one to have a given CVS module automatically publish each
update to an FTP server, which could serve as the live server. Or one
could could use it if your CVS installation is only local and you
could use it to upload your changes to your production server.
A. Credits
==========
o Jon Jenson: Thanks for helping me get going on the SDF format
already used by the Interchange documentation.
o Mike Heins & all who have contributed to the success of
Interchange: Thanks for following the Way Of The Source, for
quality programming, and for helping to making IC something to
write about.
o Thanks to the countless others who have written the CVS
documentation that is available online, which was my only source
for learning CVS.
B. Document history
===================
o May 2001. Conceived and written by Dan Browning.
o July 19, 2001. First draft complete, first public release.
C. Resources
============
C.1. CVS Documentation
----------------------
Here are some resources for learning more about CVS. I have ranked
them by the order of usefulness, which is of course, objective.
o Karl Fogel's CVS book http://cvsbook.red-bean.com/
o The official CVS manual http://www.cvshome.org/docs/manual/
o The official CVS FAQ http://faq.cvshome.org/
o The official CVS homepage http://www.cvshome.org
o Info-CVS mailing list
http://mail.gnu.org/mailman/listinfo/info-cvs
o CVS FAQ 2 http://www.cs.utah.edu/dept/old/texinfo/cvs/FAQ.txt
o Sean Dreilinger's CVS Version Control for Web Site Projects
http://durak.org/cvswebsites/
o Pascal Molli's CVS reference site
http://www.loria.fr/~molli/cvs-index.html
o CVS Tutorial
http://cellworks.washington.edu/pub/docs/cvs/tutorial/cvs_tutorial_1.html
o CVS Tutorial 2
http://www.csc.calpoly.edu/~dbutler/tutorials/winter96/cvs/
o RedHat CVS pserver setup guide
http://www.michael-amorose.com/cvs/
o CVS Add-ons http://www.cvshome.org/dev/addons.html
C.2. CVS Server Software
------------------------
o CVS RPM download (Red Hat 7.1)
ftp://speakeasy.rpmfind.net/linux/redhat/7.1/en/os/i386/RedHat/RPMS/cvs-1.11-3.i386.rpm
o Source tarballs links can can be found at cvshome.org.
C.3. CVS Client Software
------------------------
There are a variety of client access methods for using cvs on your
development box.
o There are some great graphical clients for Linux, Windows, and
Mac at http://www.cvsgui.org. These also give you the same
access to all the command line cvs commands.
o jCVS is a great cross-platform graphical cvs client available at
http://www.jcvs.org.
o jEdit is a great cross-platform text editor written in java,
which not only has a CVS module that allows you to commit
(upload) files directly from the editor, but also has a
interchange markup language (and perl language) colorizer/parser.
It is available from http://www.jedit.org.
______________________________________________________________________
Copyright 2001 Dan Browning <danpb@mail.com>. Freely redistributable
under terms of the GNU General Public License.