--- loncom/build/readme.html 2001/01/16 17:58:43 1.1 +++ loncom/build/readme.html 2001/01/17 13:04:59 1.12 @@ -1,22 +1,292 @@ + + + +LON-CAPA Software Developer Instructions + +

LON-CAPA Software Developer Instructions

+
Written by Scott Harrison, January 17, 2001 +
Last updated, January 17, 2001 +
    +
  1. Using CVS + +
  2. Viewing the software (make HTML) +
  3. Compiling the software (make build) +
  4. Adding/removing files from the LON-CAPA installation (doc/loncapafiles/loncapafiles.html) +
  5. Configurable files versus non-configurable files +
  6. Updating the non-configurable files on your machine (make install) +
  7. Updating the configurable files on your machine (make configinstall) +
  8. Building RPMs (make RPM) +
+
    + +
  1. Using CVS

    +
  2. +

    Viewing the software (make HTML)

    +Commands + +
    +cd loncom/build
    +rm -Rf HTML (or alternatively, "make clean")
    +make HTML
    +cd HTML
    +(look at the index.html file with a web browser such as Netscape)
    +
    +
    +General description of what happens +

    +This is the actual make target code. + +

    +
    +HTML:
    +        install -d HTML
    +        cp ../../doc/loncapafiles/*.gif HTML
    +        perl parse.pl ../../doc/loncapafiles/loncapafiles.html HTML > HTML/index.html
    +
    +
    + +What basically happens is that specially marked-up data in the LON-CAPA +cvs repository file doc/loncapafiles.html is parsed into a more +viewable format by loncom/build/parse.pl. The resulting +file gives a very well organized view of all the files, directories, +links, ownerships, permissions, and brief documentation of what each +file does. +

    +
  3. +

    Compiling the software (make build)

    +Commands + +
    +cd loncom/build
    +make build
    +
    +
    +General description of what happens +

    +This is the actual make target code. + +

    +
    +build:
    +        perl parse.pl ../../doc/loncapafiles/loncapafiles.html build > Makefile.build
    +        make -f Makefile.build all
    +
    +
    + +loncom/build/parse.pl reads in all the build information out +of doc/loncapafiles/loncapafiles.html. A new Makefile named +loncom/build/Makefile.build is dynamically constructed. +This dynamically generated Makefile is then run to build/compile +all the software targets from source. This currently takes 10 minutes +(depends on the speed of the machine you compile with). +

    +Example +

    +Here is information for one file tth.so provided in +doc/loncapafiles/loncapafiles.html. + +

    +
    <METAGROUP> +
    <LONCAPA TYPE=LOCATION DIST="redhat6.2" SOURCE="loncom/modules/TexConvert/tthperl/tth.so" TARGET="usr/lib/perl5/site_perl/5.005/tth.so" CATEGORY="system file"> +
    <DESCRIPTION> +
    shared library file for dynamic loading and unloading of TeX-to-HTML functionality +
    </DESCRIPTION> +
    <BUILD> +
    loncom/modules/TexConvert/tthperl/commands +
    </BUILD> +
    <DEPENDENCIES> +
    ../tthdynamic/tthfunc.c +
    ../ttmdynamic/ttmfunc.c +
    </DEPENDENCIES> +
    + +loncom/build/parse.pl sees the BUILD tags and sets up +a dynamic file Makefile.build to run the command inside the +BUILD tags (currently, DEPENDENCIES is not used for anything +besides documentation). +

    +

    +Here is an example of a dynamically generated Makefile.build +that builds two LON-CAPA files (one of which is tth.so). + +

    +all: ../homework/caparesponse/capa.so ../modules/TexConvert/tthperl/tth.so 
    +
    +../homework/caparesponse/capa.so:  ../homework/caparesponse/caparesponse.c ../ho
    +mework/caparesponse/caparesponse.pm alwaysrun
    +        cd ../homework/caparesponse/; sh ./commands
    +
    +../modules/TexConvert/tthperl/tth.so:  ../modules/TexConvert/tthperl/../tthdynam
    +ic/tthfunc.c ../modules/TexConvert/tthperl/../ttmdynamic/ttmfunc.c
    +        cd ../modules/TexConvert/tthperl/; sh ./commands
    +
    +alwaysrun:
    +
    + +

    +
  4. +

    Adding/removing files from the LON-CAPA installation (doc/loncapafiles/loncapafiles.html)

    +To add and remove (and alter) +

    +All that you have to do to alter the behavior of the installation is +edit a single file (doc/loncapafiles/loncapafiles.html). +Adding, removing, and altering files requires proper attention +to the syntax of file format of course. +

    +File Format +

    +The preceding "make build" documentation +gives an example METAGROUP entry describing one particular file. +All data within loncapafiles.html is specified according +to markup tags. The format and syntax of loncapafiles.html +is currently best described by the HTML documentation code at the beginning of +loncapafiles.html (as well as, by example, seeing how various +information is coded). All in all, the syntax is quite simple. +

    +Philosophy and notes (the thing nobody reads) +

    +Packaging the software from CVS onto a machine file system requires many +things:

    -
  5. Viewing the software (make HTML) -
  6. Compiling the software (make build) -
  7. Adding/removing files from the LON-CAPA installation (doc/loncapafiles/loncapafiles.html) -
  8. Configurable files versus non-configurable files -
  9. Updating the non-configurable files on your machine (make install) -
  10. Updating the configurable files on your machine (make configinstall) -
  11. Building RPMs (make RPM) +

    +

    +I looked into, and tried, different ways of accomplishing the above +including automake and recursive make. The automake system seemed quite +complicated (and needlessly so in terms of this project since, by and large, +it works to coordinate many different types of build/compilation parameters +whereas we are more concerned with installation parameters). Recursive make +has significant deficiencies in the sense that not all the information +is kept in one place, and there are significant levels of dependency +between all the things that must be done to keep software packaging +up to date. A particularly convincing article I found when looking into +much of this was + +"Recursive Make Considered Harmful" by Peter Miller. Complicating +matters was, at the time, it was unclear as to what categories +of software files we had, and whether or not the directory structure +of CVS would remain constant. With an ever-developing directory structure +to CVS, I preferred to organize the information on a per-file basis +as opposed to a per-directory basis (although there is a successful +implementation of a standard big Makefile in loncom/Makefile). +Additionally, a standard big Makefile assumes certain "normalcy" to +the directory structure of different potential operating system directories +(RedHat vs. Debian). +

    +

    +If you take time to look at loncapafiles.html +(and perhaps run the make HTML command) +you will find that the organizing information according to the markup +syntax in loncapafiles.html is simple. Simple is good. +

    +

    +loncom/build/parse.pl is the script (invoked automatically +by the various targets in loncom/build/Makefile) that reads +doc/loncapafiles/loncapafiles.html. parse.pl +is capable of reading and returning different types of information +from loncapafiles.html depending on how parse.pl +is invoked. parse.pl has yet to have introduced new sources +of error, and has been tested in quite a number of ways. As with +any parser however, I remain paranoid. +

    +

    +My regrets with the current system is that parse.pl is +slow (can take 1 minute to run) and includes a few tidbits of code, +specific to the make process, that probably should be in +loncom/build/Makefile. Additionally, loncapafiles.html +should have a DTD and all those other good SGML-ish things (and parsing +should be done with a real SGML-derived parser). +

    +

    +On the plus side, the parse.pl-loncapafiles.html +combination has been working very efficiently and error-free. +

    +
  12. +

    Configurable files versus non-configurable files

    +Machine-specific information is the difference +

    +The current list of configurable files for the LON-CAPA system is +/etc/httpd/access.conf. +All of these configurable files contain machine-specific information. +For instance, the LON-CAPA system relies on unique host IDs such +as msua3, s1, s2, msul1, and 103a1 (specified as a "PerlSetVar lonHostID" +field within /etc/httpd/access.conf). +Non-configurable files simply do NOT have machine-specific information. +The impact on updating software +

    +What this means in terms of software updating is that +

      +
    • non-configurable files can be simply overwritten with newer versions +(without "anything" else to worry about), +
    • and configurable files must follow these steps to be safely overwritten +
        +
      1. have their machine specific information saved, +
      2. be overwritten, and then +
      3. have their machine specific information restored.
    +

    +
  13. +

    Updating the non-configurable files on your machine (make install)

    + + +
  14. +

    Updating the configurable files on your machine (make configinstall)

    + + +
  15. +

    Building RPMs (make RPM)

    +
+ + + + +